Climate and average weather in Bỉm Sơn
In Bỉm Sơn, the summers are oppressive, sweltering, showery, and mostly cloudy and the winters are mild and mostly cloudy.
Over the course of the year, the temperature in Bỉm Sơn typically varies from 15°C to 34°C, and is rarely below 10°C or above 37°C. June is the hottest month of the year, while January is the coldest.
Based on the travel score, the best times of year to visit Bỉm Sơn for warm-weather activities are from early January to mid April and late October to late December.
- Hottest
- Jun
- 34°
- Coldest
- Jan
- 15°
- Wettest
- Aug
- 324 mm
- Driest
- Feb
- 17 mm
- Rain / yr
- 1574 mm
- 145 wet days
- Daylight
- 10.8–13.2 h
- shortest–longest
- Elevation
- 7 m
- 20.1°N
- Clearest
- Nov
- 59% cloud
Bỉm Sơn is district-level town in Thanh Hóa province, Vietnam.
- Density
- 802/km²
- people per km²
- Founded
- 1981
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Bỉm Sơn weather by month, at a glance
The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.
Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around early January to mid April.
Temperature through the year
Daily average highs and lows in Bỉm Sơn, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
The hot season lasts 5.0 months, from April 27 to September 24, with daily high temperatures above 31°C. The hottest month of the year in Bỉm Sơn is June, with an average high of 34°C and low of 27°C.
The cool season lasts 2.7 months, from December 6 to February 25, with daily high temperatures below 23°C. The coldest month of the year in Bỉm Sơn is January, with an average low of 15°C and high of 21°C.
Days typically run about 6°C warmer than nights year-round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 21 | 22 | 25 | 29 | 32 | 34 | 33 | 32 | 31 | 29 | 26 | 22 |
| Avg low (°C) | 15 | 16 | 19 | 22 | 25 | 27 | 27 | 26 | 25 | 23 | 19 | 16 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | 21 | 15 |
| Feb | 22 | 16 |
| Mar | 25 | 19 |
| Apr | 29 | 22 |
| May | 32 | 25 |
| Jun | 34 | 27 |
| Jul | 33 | 27 |
| Aug | 32 | 26 |
| Sep | 31 | 25 |
| Oct | 29 | 23 |
| Nov | 26 | 19 |
| Dec | 22 | 16 |
How hot and cold Bỉm Sơn really feels
The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.
On the hottest afternoons, once humidity is folded in, Bỉm Sơn feels like about 43°C (around June 21). About 182 days a year carry some heat stress, and 114 of them tip into dangerous heat (feels-like above 39°C), peaking in June.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels-like high (°C) | 21 | 22 | 25 | 32 | 39 | 43 | 42 | 41 | 38 | 32 | 26 | 22 |
| Air high (°C) | 21 | 22 | 25 | 29 | 32 | 34 | 33 | 32 | 31 | 29 | 26 | 22 |
| Feels-like low (°C) | 15 | 16 | 19 | 22 | 25 | 27 | 27 | 26 | 25 | 22 | 19 | 16 |
| Air low (°C) | 15 | 16 | 19 | 22 | 25 | 27 | 27 | 26 | 25 | 23 | 19 | 16 |
| Feels-like high (°C) | Air high (°C) | Feels-like low (°C) | Air low (°C) | |
|---|---|---|---|---|
| Jan | 21 | 21 | 15 | 15 |
| Feb | 22 | 22 | 16 | 16 |
| Mar | 25 | 25 | 19 | 19 |
| Apr | 32 | 29 | 22 | 22 |
| May | 39 | 32 | 25 | 25 |
| Jun | 43 | 34 | 27 | 27 |
| Jul | 42 | 33 | 27 | 27 |
| Aug | 41 | 32 | 26 | 26 |
| Sep | 38 | 31 | 25 | 25 |
| Oct | 32 | 29 | 22 | 23 |
| Nov | 26 | 26 | 19 | 19 |
| Dec | 22 | 22 | 16 | 16 |
Average hourly temperature in Bỉm Sơn
A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on June afternoons, near 34°C, and coldest before dawn in January, near 15°C.
Bỉm Sơn weather by month
Every month at a glance. Click a month for its detailed page.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 21° / 15° | 29 | 5.6 | 10.9 | 6.7 |
| Feb | 22° / 16° | 17 | 4.4 | 11.3 | 7.0 |
| Mar | 25° / 19° | 35 | 6.7 | 11.9 | 7.0 |
| Apr | 29° / 22° | 64 | 8.6 | 12.4 | 5.5 |
| May | 32° / 25° | 178 | 15.5 | 12.9 | 3.3 |
| Jun | 34° / 27° | 178 | 14.6 | 13.2 | 2.5 |
| Jul | 33° / 27° | 234 | 17.8 | 13.1 | 2.5 |
| Aug | 32° / 26° | 324 | 23 | 12.7 | 2.6 |
| Sep | 31° / 25° | 278 | 20.8 | 12.1 | 3.2 |
| Oct | 29° / 23° | 156 | 14.5 | 11.5 | 5.1 |
| Nov | 26° / 19° | 57 | 7.9 | 11 | 6.9 |
| Dec | 22° / 16° | 25 | 5.4 | 10.8 | 7.1 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
Bỉm Sơn gets about 1574 mm of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.
The wetter season lasts 5.7 months, from around May 4 to Oct 22, peaking in September at about 81% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Feb 4.
August is the wettest month by volume, with 324 mm over about 23 wet days; February is the driest, with 17 mm.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 17 | 16 | 22 | 29 | 49 | 50 | 58 | 74 | 70 | 46 | 27 | 18 |
| Rain days | 6 | 4 | 7 | 9 | 16 | 15 | 18 | 23 | 21 | 15 | 8 | 5 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 17 | 6 |
| Feb | 16 | 4 |
| Mar | 22 | 7 |
| Apr | 29 | 9 |
| May | 49 | 16 |
| Jun | 50 | 15 |
| Jul | 58 | 18 |
| Aug | 74 | 23 |
| Sep | 70 | 21 |
| Oct | 46 | 15 |
| Nov | 27 | 8 |
| Dec | 18 | 5 |
Monthly rainfall
Over a full year, Bỉm Sơn collects about 1574 mm of rain across 145 wet days — roughly 131 mm in an average month.
It doesn’t fall evenly. August is the wettest month with 324 mm, while February is the driest at just 17 mm. The three wettest months alone bring about 53% of the year’s total.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 29 | 17 | 35 | 64 | 178 | 178 | 234 | 324 | 278 | 156 | 57 | 25 |
| Rain days | 6 | 4 | 7 | 9 | 16 | 15 | 18 | 23 | 21 | 15 | 8 | 5 |
| Rainfall (mm) | Rain days | |
|---|---|---|
| Jan | 29 | 6 |
| Feb | 17 | 4 |
| Mar | 35 | 7 |
| Apr | 64 | 9 |
| May | 178 | 16 |
| Jun | 178 | 15 |
| Jul | 234 | 18 |
| Aug | 324 | 23 |
| Sep | 278 | 21 |
| Oct | 156 | 15 |
| Nov | 57 | 8 |
| Dec | 25 | 5 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In Bỉm Sơn, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.
The clearer part of the year begins around September 15 and lasts for 3.6 months, ending around January 3. The clearest month is November, when the sky is clear, mostly clear, or partly cloudy 48% of the time on average.
The cloudier part of the year begins around May 15 and lasts for 4.0 months, ending around September 14. The cloudiest month is June, when it is overcast or mostly cloudy 87% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 23 | 23 | 24 | 28 | 25 | 13 | 15 | 16 | 29 | 47 | 48 | 36 |
| Cloudier (%) | 77 | 77 | 76 | 72 | 75 | 87 | 85 | 84 | 71 | 53 | 52 | 64 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 23 | 77 |
| Feb | 23 | 77 |
| Mar | 24 | 76 |
| Apr | 28 | 72 |
| May | 25 | 75 |
| Jun | 13 | 87 |
| Jul | 15 | 85 |
| Aug | 16 | 84 |
| Sep | 29 | 71 |
| Oct | 47 | 53 |
| Nov | 48 | 52 |
| Dec | 36 | 64 |
Daylight, sunrise and sunset
Hours of daylight through the year, with sunrise and sunset times.
The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 5, brings about 13 h 12 min of light; the shortest, around January 1, only 10 h 48 min — a swing of roughly 2 h 24 min.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 10.9 | 11.3 | 11.9 | 12.4 | 12.9 | 13.2 | 13.1 | 12.7 | 12.1 | 11.5 | 11.0 | 10.8 |
| Sunrise (AM) | 6:39 | 6:32 | 6:10 | 5:43 | 5:24 | 5:21 | 5:29 | 5:40 | 5:47 | 5:56 | 6:11 | 6:29 |
| Sunset (PM) | 5:33 | 5:51 | 6:02 | 6:11 | 6:21 | 6:33 | 6:35 | 6:21 | 5:54 | 5:28 | 5:13 | 5:16 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 10.9 | 6:39 | 5:33 |
| Feb | 11.3 | 6:32 | 5:51 |
| Mar | 11.9 | 6:10 | 6:02 |
| Apr | 12.4 | 5:43 | 6:11 |
| May | 12.9 | 5:24 | 6:21 |
| Jun | 13.2 | 5:21 | 6:33 |
| Jul | 13.1 | 5:29 | 6:35 |
| Aug | 12.7 | 5:40 | 6:21 |
| Sep | 12.1 | 5:47 | 5:54 |
| Oct | 11.5 | 5:56 | 5:28 |
| Nov | 11.0 | 6:11 | 5:13 |
| Dec | 10.8 | 6:29 | 5:16 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
Bỉm Sơn averages about 5 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 2 and 10 days.
The sunnier stretch runs 3.7 months, from around Sep 13 to Jan 4. The sunniest month is October, with roughly 9 sunny days (mixed).
The greyest month is June, down near 2 sunny days — about 77% fewer than the October peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 4 | 4 | 4 | 4 | 3 | 2 | 3 | 3 | 5 | 9 | 8 | 7 |
| Sky | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Mixed | Mixed | Gloomy |
| Sunny days | Sky | |
|---|---|---|
| Jan | 4 | Gloomy |
| Feb | 4 | Gloomy |
| Mar | 4 | Gloomy |
| Apr | 4 | Gloomy |
| May | 3 | Gloomy |
| Jun | 2 | Gloomy |
| Jul | 3 | Gloomy |
| Aug | 3 | Gloomy |
| Sep | 5 | Gloomy |
| Oct | 9 | Mixed |
| Nov | 8 | Mixed |
| Dec | 7 | Gloomy |
Humidity comfort
Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.
Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.
In Bỉm Sơn, how humid it feels changes dramatically over the year.
The more humid part of the year lasts 7.6 months, from around March 20 to November 4. The muggiest month is May, when the air feels humid, muggy or worse about 100% of the time.
The most comfortable stretch runs from around November 5 to March 19, and January is the most comfortable month — the air is dry or comfortable 58% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 41 | 28 | 10 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 11 | 35 |
| Comfortable (%) | 17 | 17 | 11 | 4 | 0 | 0 | 0 | 0 | 0 | 4 | 16 | 20 |
| Humid (%) | 20 | 22 | 18 | 9 | 2 | 0 | 0 | 0 | 1 | 11 | 22 | 22 |
| Muggy (%) | 20 | 24 | 32 | 19 | 7 | 1 | 0 | 0 | 5 | 20 | 22 | 18 |
| Oppressive (%) | 2 | 10 | 27 | 40 | 23 | 8 | 5 | 2 | 19 | 38 | 25 | 5 |
| Miserable (%) | 0 | 0 | 1 | 28 | 69 | 91 | 95 | 98 | 75 | 25 | 5 | 0 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| Jan | 41 | 17 | 20 | 20 | 2 | 0 |
| Feb | 28 | 17 | 22 | 24 | 10 | 0 |
| Mar | 10 | 11 | 18 | 32 | 27 | 1 |
| Apr | 1 | 4 | 9 | 19 | 40 | 28 |
| May | 0 | 0 | 2 | 7 | 23 | 69 |
| Jun | 0 | 0 | 0 | 1 | 8 | 91 |
| Jul | 0 | 0 | 0 | 0 | 5 | 95 |
| Aug | 0 | 0 | 0 | 0 | 2 | 98 |
| Sep | 0 | 0 | 1 | 5 | 19 | 75 |
| Oct | 1 | 4 | 11 | 20 | 38 | 25 |
| Nov | 11 | 16 | 22 | 22 | 25 | 5 |
| Dec | 35 | 20 | 22 | 18 | 5 | 0 |
Wind
Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.
This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.
Wind in Bỉm Sơn is steady company: average speeds sit near 8 km/h — calm — in every month of the year, with no meaningful windy or calm season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 9 | 9 | 9 | 9 | 8 | 8 | 8 | 7 | 7 | 9 | 9 | 9 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 9 | calm |
| Feb | 9 | calm |
| Mar | 9 | calm |
| Apr | 9 | calm |
| May | 8 | calm |
| Jun | 8 | calm |
| Jul | 8 | calm |
| Aug | 7 | calm |
| Sep | 7 | calm |
| Oct | 9 | calm |
| Nov | 9 | calm |
| Dec | 9 | calm |
Hazard calendar for Bỉm Sơn
When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.
Bỉm Sơn sits in the Pacific typhoon belt; the season peaks July–October.
Bỉm Sơn's monsoon runs May–October, when most of the year's rain falls.
Best time to visit Bỉm Sơn
To characterize how pleasant the weather is in Bỉm Sơn throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around mid January, Bỉm Sơn is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.
Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.
The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit Bỉm Sơn for general outdoor tourist activities is from late October to mid April, with a peak score in the first week of December.
The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Travel score (0–10) | 6.7 | 7.0 | 7.0 | 5.4 | 3.3 | 2.5 | 2.5 | 2.6 | 3.2 | 5.1 | 6.9 | 7.1 |
| Rating | good | good | good | fair | poor | poor | poor | poor | poor | fair | good | good |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 6.7 | good |
| Feb | 7.0 | good |
| Mar | 7.0 | good |
| Apr | 5.4 | fair |
| May | 3.3 | poor |
| Jun | 2.5 | poor |
| Jul | 2.5 | poor |
| Aug | 2.6 | poor |
| Sep | 3.2 | poor |
| Oct | 5.1 | fair |
| Nov | 6.9 | good |
| Dec | 7.1 | good |
The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best times of year to visit Bỉm Sơn for hot-weather activities run from late February to mid May and again from late September to early December, with a peak score in the second week of April.
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
What to pack for Bỉm Sơn, by month
Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.
For a warm-season trip around June (highs near 34°C), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 21°C), pack a light layer.
In June, Bỉm Sơn sees daytime highs around 34°C and nights near 27°C. Pack light clothes and rain gear. Worth having: sun protection. About 15 days see rain.
Sea temperature near Bỉm Sơn
Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.
The sea at the nearest coast (about 36 km away) is warmest in August at about 30°C and coldest in February near 20°C.
The water stays above 20°C all year — warm enough for a swim any month.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 21 | 20 | 21 | 24 | 28 | 29 | 30 | 30 | 29 | 28 | 26 | 23 |
| Comfort | Refreshing | Refreshing | Refreshing | Refreshing | Warm | Tropical | Tropical | Tropical | Tropical | Warm | Warm | Refreshing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 21 | Refreshing |
| Feb | 20 | Refreshing |
| Mar | 21 | Refreshing |
| Apr | 24 | Refreshing |
| May | 28 | Warm |
| Jun | 29 | Tropical |
| Jul | 30 | Tropical |
| Aug | 30 | Tropical |
| Sep | 29 | Tropical |
| Oct | 28 | Warm |
| Nov | 26 | Warm |
| Dec | 23 | Refreshing |
UV index (midday) in Bỉm Sơn by month
Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.
Under clear skies, the midday UV index in Bỉm Sơn peaks around July 14 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 6 (high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 7 | 9 | 10 | 8 | 10 | 12 | 12 | 11 | 9 | 9 | 7 | 6 |
| Level | Very high | Very high | Very high | Very high | Very high | Extreme | Extreme | Extreme | Very high | Very high | High | High |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 7 | Very high |
| Feb | 9 | Very high |
| Mar | 10 | Very high |
| Apr | 8 | Very high |
| May | 10 | Very high |
| Jun | 12 | Extreme |
| Jul | 12 | Extreme |
| Aug | 11 | Extreme |
| Sep | 9 | Very high |
| Oct | 9 | Very high |
| Nov | 7 | High |
| Dec | 6 | High |
Average hourly UV index in Bỉm Sơn
Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.
The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
UV falls off far faster than brightness as the sun drops, so even in July the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 6.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV ≥ 3 (h/day) | 6 | 6.5 | 7 | 7 | 7.5 | 8.5 | 8.5 | 8 | 7 | 6.5 | 6 | 5.5 |
| UV ≥ 6 (h/day) | 3 | 4 | 4.5 | 4 | 5 | 6 | 6.5 | 6 | 4.5 | 4 | 2.5 | 1.5 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 6 | 3 |
| Feb | 6.5 | 4 |
| Mar | 7 | 4.5 |
| Apr | 7 | 4 |
| May | 7.5 | 5 |
| Jun | 8.5 | 6 |
| Jul | 8.5 | 6.5 |
| Aug | 8 | 6 |
| Sep | 7 | 4.5 |
| Oct | 6.5 | 4 |
| Nov | 6 | 2.5 |
| Dec | 5.5 | 1.5 |
Air quality in Bỉm Sơn by month
Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.
Air quality in Bỉm Sơn is worst in December — around 134 µg/m³ PM2.5 (unhealthy), about 3.8× the cleanest month (July, 35 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 126 | 106 | 94 | 87 | 60 | 42 | 35 | 46 | 69 | 93 | 116 | 134 |
| Level | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Poor | Moderate | Poor | Unhealthy | Unhealthy | Unhealthy | Unhealthy |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 126 | Unhealthy |
| Feb | 106 | Unhealthy |
| Mar | 94 | Unhealthy |
| Apr | 87 | Unhealthy |
| May | 60 | Unhealthy |
| Jun | 42 | Poor |
| Jul | 35 | Moderate |
| Aug | 46 | Poor |
| Sep | 69 | Unhealthy |
| Oct | 93 | Unhealthy |
| Nov | 116 | Unhealthy |
| Dec | 134 | Unhealthy |
Growing season
Bỉm Sơn is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Frost-free chance (%) | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Frost nights | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Frost-free chance (%) | Frost nights | |
|---|---|---|
| Jan | 100 | 0 |
| Feb | 100 | 0 |
| Mar | 100 | 0 |
| Apr | 100 | 0 |
| May | 100 | 0 |
| Jun | 100 | 0 |
| Jul | 100 | 0 |
| Aug | 100 | 0 |
| Sep | 100 | 0 |
| Oct | 100 | 0 |
| Nov | 100 | 0 |
| Dec | 100 | 0 |
Growing degree days
Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Bỉm Sơn banks about 5,424 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around June.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Growing degree days (°C·days) | 240 | 257 | 366 | 469 | 581 | 614 | 626 | 596 | 538 | 484 | 376 | 279 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 240 |
| Feb | 257 |
| Mar | 366 |
| Apr | 469 |
| May | 581 |
| Jun | 614 |
| Jul | 626 |
| Aug | 596 |
| Sep | 538 |
| Oct | 484 |
| Nov | 376 |
| Dec | 279 |
Solar energy
Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.
Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.
Bỉm Sơn receives about 4.0 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 2.4 and 5.3 kWh/m².
The brighter stretch of the year lasts 6.2 months, from around Apr 5 to Oct 10. The brightest month is June, averaging about 5.3 kWh/m² (bright).
The dimmest month is January, down near 2.5 kWh/m² — roughly 53% less than the June peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 2.4 | 2.8 | 3.4 | 4.5 | 5.2 | 5.3 | 5.2 | 4.7 | 4.3 | 3.9 | 3.3 | 2.7 |
| Level | Moderate | Moderate | Moderate | Bright | Bright | Bright | Bright | Bright | Bright | Moderate | Moderate | Moderate |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 2.4 | Moderate |
| Feb | 2.8 | Moderate |
| Mar | 3.4 | Moderate |
| Apr | 4.5 | Bright |
| May | 5.2 | Bright |
| Jun | 5.3 | Bright |
| Jul | 5.2 | Bright |
| Aug | 4.7 | Bright |
| Sep | 4.3 | Bright |
| Oct | 3.9 | Moderate |
| Nov | 3.3 | Moderate |
| Dec | 2.7 | Moderate |
Where is Bỉm Sơn?
Bỉm Sơn sits at 20.1°N, 105.9°E, 7 m above sea level, in Vietnam. The nearest listed city is Nga Sơn, 14 km away.
Topography around Bỉm Sơn
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Bỉm Sơn.
Within 3 km, the terrain around Bỉm Sơn has only modest variations in elevation — a maximum elevation change of 99 m around an average of 13 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 327 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,500 m.
The land around Bỉm Sơn is covered by trees (39%) and cropland (27%) within 3 km, trees (52%) and cropland (33%) within 16 km, and trees (41%), cropland (29%) and water (23%) within 80 km.
Vietnam travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type A / B / C / F
- 220 V · 50 Hz
- Prices
- ≈ 29% of US
- price level, 2025
- GDP per capita
- $5,066
- 2025
- Happiness
- 6.4 / 10
- World Happiness, 2025
- Safe drinking water
- 59%
- of population, 2024
- Homicide rate
- 1.5
- per 100k, 2011
- Road deaths
- 30.6
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- Moderate
- EF EPI 500
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Bỉm Sơn (20.0781°, 105.8603°, elevation 7 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).