Climate and average weather in Mường Lay
In Mường Lay, the summers are muggy, hot, wet, and mostly cloudy and the winters are mild and partly cloudy.
Over the course of the year, the temperature in Mường Lay typically varies from 12°C to 29°C, and is rarely below 8°C or above 33°C. May is the hottest month of the year, while January is the coldest.
Based on the travel score, the best times of year to visit Mường Lay for warm-weather activities are from early January to late March and mid October to late December.
- Hottest
- May
- 29°
- Coldest
- Jan
- 12°
- Wettest
- Jun
- 455 mm
- Driest
- Dec
- 47 mm
- Rain / yr
- 2430 mm
- 206 wet days
- Daylight
- 10.7–13.3 h
- shortest–longest
- Elevation
- 496 m
- 22.0°N
- Clearest
- Mar
- 49% cloud
Mường Lay is old town of Dien Bien province, Vietnam.
- Density
- 179/km²
- people per km²
- Founded
- 1971
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Mường Lay 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 late March.
Temperature through the year
Daily average highs and lows in Mường Lay, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
The hot season lasts 6.6 months, from March 30 to October 16, with daily high temperatures above 27°C. The hottest month of the year in Mường Lay is May, with an average high of 29°C and low of 21°C.
The cool season lasts 2.3 months, from December 3 to February 9, with daily high temperatures below 22°C. The coldest month of the year in Mường Lay is January, with an average low of 12°C and high of 21°C.
Days typically run about 8°C warmer than nights, with the widest day–night swing (around 11°C) in March.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 21 | 23 | 26 | 28 | 29 | 29 | 29 | 29 | 29 | 27 | 24 | 21 |
| Avg low (°C) | 12 | 12 | 15 | 19 | 21 | 23 | 23 | 23 | 22 | 20 | 16 | 13 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | 21 | 12 |
| Feb | 23 | 12 |
| Mar | 26 | 15 |
| Apr | 28 | 19 |
| May | 29 | 21 |
| Jun | 29 | 23 |
| Jul | 29 | 23 |
| Aug | 29 | 23 |
| Sep | 29 | 22 |
| Oct | 27 | 20 |
| Nov | 24 | 16 |
| Dec | 21 | 13 |
How hot and cold Mường Lay 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, Mường Lay feels like about 33°C (around June 4). About 92 days a year carry some heat stress, peaking in June.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels-like high (°C) | 21 | 23 | 27 | 30 | 32 | 32 | 32 | 32 | 32 | 28 | 24 | 21 |
| Air high (°C) | 21 | 23 | 26 | 28 | 29 | 29 | 29 | 29 | 29 | 27 | 24 | 21 |
| Feels-like low (°C) | 12 | 12 | 15 | 19 | 21 | 23 | 23 | 23 | 22 | 20 | 16 | 13 |
| Air low (°C) | 12 | 12 | 15 | 19 | 21 | 23 | 23 | 23 | 22 | 20 | 16 | 13 |
| Feels-like high (°C) | Air high (°C) | Feels-like low (°C) | Air low (°C) | |
|---|---|---|---|---|
| Jan | 21 | 21 | 12 | 12 |
| Feb | 23 | 23 | 12 | 12 |
| Mar | 27 | 26 | 15 | 15 |
| Apr | 30 | 28 | 19 | 19 |
| May | 32 | 29 | 21 | 21 |
| Jun | 32 | 29 | 23 | 23 |
| Jul | 32 | 29 | 23 | 23 |
| Aug | 32 | 29 | 23 | 23 |
| Sep | 32 | 29 | 22 | 22 |
| Oct | 28 | 27 | 20 | 20 |
| Nov | 24 | 24 | 16 | 16 |
| Dec | 21 | 21 | 13 | 13 |
Average hourly temperature in Mường Lay
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 May afternoons, near 29°C, and coldest before dawn in January, near 12°C.
Mường Lay 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° / 12° | 59 | 8 | 10.8 | 6.8 |
| Feb | 23° / 12° | 54 | 8.3 | 11.2 | 7.1 |
| Mar | 26° / 15° | 123 | 13.1 | 11.8 | 6.3 |
| Apr | 28° / 19° | 219 | 19.5 | 12.5 | 4.7 |
| May | 29° / 21° | 328 | 25.2 | 13 | 3.5 |
| Jun | 29° / 23° | 455 | 28.3 | 13.3 | 2.9 |
| Jul | 29° / 23° | 453 | 29.4 | 13.2 | 3.0 |
| Aug | 29° / 23° | 364 | 26.9 | 12.8 | 3.2 |
| Sep | 29° / 22° | 187 | 19.7 | 12.1 | 4.2 |
| Oct | 27° / 20° | 86 | 13.7 | 11.5 | 5.9 |
| Nov | 24° / 16° | 55 | 8 | 10.9 | 7.2 |
| Dec | 21° / 13° | 47 | 6.2 | 10.7 | 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.
Mường Lay gets about 2430 mm of precipitation a year. On a typical day the chance of rain is very wet, but that rises and falls sharply with the seasons.
The wetter season lasts 5.8 months, from around Apr 1 to Sep 25, peaking in June at about 96% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Dec 20.
June is the wettest month by volume, with 455 mm over about 28 wet days; December is the driest, with 47 mm.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 25 | 30 | 42 | 65 | 82 | 94 | 95 | 86 | 66 | 44 | 28 | 20 |
| Rain days | 8 | 8 | 13 | 20 | 25 | 28 | 29 | 27 | 20 | 14 | 8 | 6 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 25 | 8 |
| Feb | 30 | 8 |
| Mar | 42 | 13 |
| Apr | 65 | 20 |
| May | 82 | 25 |
| Jun | 94 | 28 |
| Jul | 95 | 29 |
| Aug | 86 | 27 |
| Sep | 66 | 20 |
| Oct | 44 | 14 |
| Nov | 28 | 8 |
| Dec | 20 | 6 |
Monthly rainfall
Over a full year, Mường Lay collects about 2430 mm of rain across 206 wet days — roughly 202 mm in an average month.
It doesn’t fall evenly. June is the wettest month with 455 mm, while December is the driest at just 47 mm. The three wettest months alone bring about 52% of the year’s total.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 59 | 54 | 123 | 219 | 328 | 455 | 453 | 364 | 187 | 86 | 55 | 47 |
| Rain days | 8 | 8 | 13 | 20 | 25 | 28 | 29 | 27 | 20 | 14 | 8 | 6 |
| Rainfall (mm) | Rain days | |
|---|---|---|
| Jan | 59 | 8 |
| Feb | 54 | 8 |
| Mar | 123 | 13 |
| Apr | 219 | 20 |
| May | 328 | 25 |
| Jun | 455 | 28 |
| Jul | 453 | 29 |
| Aug | 364 | 27 |
| Sep | 187 | 20 |
| Oct | 86 | 14 |
| Nov | 55 | 8 |
| Dec | 47 | 6 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In Mường Lay, 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 23 and lasts for 7.5 months, ending around May 9. The clearest month is March, when the sky is clear, mostly clear, or partly cloudy 61% of the time on average.
The cloudier part of the year begins around May 10 and lasts for 4.5 months, ending around September 22. The cloudiest month is June, when it is overcast or mostly cloudy 93% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 47 | 59 | 61 | 54 | 31 | 7 | 9 | 17 | 34 | 50 | 55 | 50 |
| Cloudier (%) | 53 | 41 | 39 | 46 | 69 | 93 | 91 | 83 | 66 | 50 | 45 | 50 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 47 | 53 |
| Feb | 59 | 41 |
| Mar | 61 | 39 |
| Apr | 54 | 46 |
| May | 31 | 69 |
| Jun | 7 | 93 |
| Jul | 9 | 91 |
| Aug | 17 | 83 |
| Sep | 34 | 66 |
| Oct | 50 | 50 |
| Nov | 55 | 45 |
| Dec | 50 | 50 |
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 2, brings about 13 h 18 min of light; the shortest, around January 1, only 10 h 42 min — a swing of roughly 2 h 36 min.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 10.8 | 11.2 | 11.8 | 12.5 | 13.0 | 13.3 | 13.2 | 12.8 | 12.1 | 11.5 | 10.9 | 10.7 |
| Sunrise (AM) | 6:53 | 6:45 | 6:22 | 5:52 | 5:32 | 5:28 | 5:36 | 5:49 | 5:58 | 6:08 | 6:25 | 6:44 |
| Sunset (PM) | 5:40 | 5:59 | 6:12 | 6:23 | 6:35 | 6:48 | 6:50 | 6:34 | 6:06 | 5:37 | 5:21 | 5:24 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 10.8 | 6:53 | 5:40 |
| Feb | 11.2 | 6:45 | 5:59 |
| Mar | 11.8 | 6:22 | 6:12 |
| Apr | 12.5 | 5:52 | 6:23 |
| May | 13.0 | 5:32 | 6:35 |
| Jun | 13.3 | 5:28 | 6:48 |
| Jul | 13.2 | 5:36 | 6:50 |
| Aug | 12.8 | 5:49 | 6:34 |
| Sep | 12.1 | 5:58 | 6:06 |
| Oct | 11.5 | 6:08 | 5:37 |
| Nov | 10.9 | 6:25 | 5:21 |
| Dec | 10.7 | 6:44 | 5:24 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
Mường Lay averages about 7 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 1 and 14 days.
The sunnier stretch runs 7.3 months, from around Sep 26 to May 6. The sunniest month is March, with roughly 13 sunny days (mixed).
The greyest month is June, down near 1 sunny days — about 94% fewer than the March peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 9 | 11 | 13 | 10 | 5 | 1 | 1 | 2 | 5 | 8 | 10 | 9 |
| Sky | Mixed | Mixed | Mixed | Mixed | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Mixed | Mixed |
| Sunny days | Sky | |
|---|---|---|
| Jan | 9 | Mixed |
| Feb | 11 | Mixed |
| Mar | 13 | Mixed |
| Apr | 10 | Mixed |
| May | 5 | Gloomy |
| Jun | 1 | Gloomy |
| Jul | 1 | Gloomy |
| Aug | 2 | Gloomy |
| Sep | 5 | Gloomy |
| Oct | 8 | Gloomy |
| Nov | 10 | Mixed |
| Dec | 9 | Mixed |
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 Mường Lay, how humid it feels changes dramatically over the year.
The more humid part of the year lasts 7.5 months, from around March 21 to November 3. The muggiest month is May, when the air feels humid, muggy or worse about 99% of the time.
The most comfortable stretch runs from around November 4 to March 20, and January is the most comfortable month — the air is dry or comfortable 94% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 49 | 37 | 11 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 11 | 41 |
| Comfortable (%) | 45 | 44 | 27 | 4 | 1 | 0 | 0 | 0 | 0 | 7 | 30 | 40 |
| Humid (%) | 6 | 18 | 45 | 20 | 5 | 0 | 0 | 0 | 3 | 19 | 36 | 17 |
| Muggy (%) | 0 | 1 | 17 | 57 | 26 | 3 | 0 | 2 | 21 | 50 | 22 | 2 |
| Oppressive (%) | 0 | 0 | 0 | 18 | 68 | 94 | 97 | 96 | 75 | 22 | 1 | 0 |
| Miserable (%) | 0 | 0 | 0 | 0 | 1 | 3 | 2 | 2 | 0 | 0 | 0 | 0 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| Jan | 49 | 45 | 6 | 0 | 0 | 0 |
| Feb | 37 | 44 | 18 | 1 | 0 | 0 |
| Mar | 11 | 27 | 45 | 17 | 0 | 0 |
| Apr | 1 | 4 | 20 | 57 | 18 | 0 |
| May | 0 | 1 | 5 | 26 | 68 | 1 |
| Jun | 0 | 0 | 0 | 3 | 94 | 3 |
| Jul | 0 | 0 | 0 | 0 | 97 | 2 |
| Aug | 0 | 0 | 0 | 2 | 96 | 2 |
| Sep | 0 | 0 | 3 | 21 | 75 | 0 |
| Oct | 1 | 7 | 19 | 50 | 22 | 0 |
| Nov | 11 | 30 | 36 | 22 | 1 | 0 |
| Dec | 41 | 40 | 17 | 2 | 0 | 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 Mường Lay is steady company: average speeds sit near 3 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) | 3 | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 2 | 3 | 3 | 3 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 3 | calm |
| Feb | 3 | calm |
| Mar | 3 | calm |
| Apr | 3 | calm |
| May | 3 | calm |
| Jun | 2 | calm |
| Jul | 2 | calm |
| Aug | 2 | calm |
| Sep | 2 | calm |
| Oct | 3 | calm |
| Nov | 3 | calm |
| Dec | 3 | calm |
Hazard calendar for Mường Lay
When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.
Mường Lay's monsoon runs April–August, when most of the year's rain falls.
Best time to visit Mường Lay
To characterize how pleasant the weather is in Mường Lay throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around mid January, Mường Lay 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 Mường Lay for general outdoor tourist activities is from mid October to late March, with a peak score in the third week of November.
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) | 6.8 | 7.1 | 6.3 | 4.7 | 3.5 | 2.9 | 3.0 | 3.2 | 4.2 | 5.9 | 7.2 | 7.2 |
| Rating | good | good | good | fair | poor | poor | poor | poor | fair | good | good | good |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 6.8 | good |
| Feb | 7.1 | good |
| Mar | 6.3 | good |
| Apr | 4.7 | fair |
| May | 3.5 | poor |
| Jun | 2.9 | poor |
| Jul | 3.0 | poor |
| Aug | 3.2 | poor |
| Sep | 4.2 | fair |
| Oct | 5.9 | good |
| Nov | 7.2 | good |
| Dec | 7.2 | 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 Mường Lay for hot-weather activities run from mid February to late April and again from mid September to early December, with a peak score in the first week of March.
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 Mường Lay, 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 May (highs near 29°C), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 21°C), pack rain gear.
In May, Mường Lay sees daytime highs around 29°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 25 days see rain.
UV index (midday) in Mường Lay 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 Mường Lay peaks around June 19 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 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 | 11 | 9 | 11 | 14 | 13 | 12 | 10 | 9 | 8 | 6 |
| Level | High | Very high | Extreme | Very high | Extreme | Extreme | Extreme | Extreme | Very high | Very high | Very high | High |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 7 | High |
| Feb | 9 | Very high |
| Mar | 11 | Extreme |
| Apr | 9 | Very high |
| May | 11 | Extreme |
| Jun | 14 | Extreme |
| Jul | 13 | Extreme |
| Aug | 12 | Extreme |
| Sep | 10 | Very high |
| Oct | 9 | Very high |
| Nov | 8 | Very high |
| Dec | 6 | High |
Average hourly UV index in Mường Lay
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 June 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 | 7.5 | 7.5 | 8 | 8.5 | 8.5 | 8.5 | 7.5 | 7 | 6 | 5 |
| UV ≥ 6 (h/day) | 2 | 4 | 5.5 | 4.5 | 6 | 6.5 | 6.5 | 6 | 5 | 4.5 | 3.5 | 0 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 6 | 2 |
| Feb | 6.5 | 4 |
| Mar | 7.5 | 5.5 |
| Apr | 7.5 | 4.5 |
| May | 8 | 6 |
| Jun | 8.5 | 6.5 |
| Jul | 8.5 | 6.5 |
| Aug | 8.5 | 6 |
| Sep | 7.5 | 5 |
| Oct | 7 | 4.5 |
| Nov | 6 | 3.5 |
| Dec | 5 | 0 |
Air quality in Mường Lay 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 Mường Lay is worst in April — around 99 µg/m³ PM2.5 (unhealthy), about 8.1× the cleanest month (July, 12 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) | 31 | 41 | 73 | 99 | 32 | 14 | 12 | 13 | 17 | 23 | 26 | 30 |
| Level | Moderate | Poor | Unhealthy | Unhealthy | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 31 | Moderate |
| Feb | 41 | Poor |
| Mar | 73 | Unhealthy |
| Apr | 99 | Unhealthy |
| May | 32 | Moderate |
| Jun | 14 | Moderate |
| Jul | 12 | Moderate |
| Aug | 13 | Moderate |
| Sep | 17 | Moderate |
| Oct | 23 | Moderate |
| Nov | 26 | Moderate |
| Dec | 30 | Moderate |
Growing season
Mường Lay 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. Mường Lay banks about 4,455 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) | 193 | 215 | 335 | 403 | 471 | 476 | 487 | 489 | 456 | 411 | 303 | 216 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 193 |
| Feb | 215 |
| Mar | 335 |
| Apr | 403 |
| May | 471 |
| Jun | 476 |
| Jul | 487 |
| Aug | 489 |
| Sep | 456 |
| Oct | 411 |
| Nov | 303 |
| Dec | 216 |
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.
Mường Lay receives about 4.1 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.1 and 5.3 kWh/m².
The brighter stretch of the year lasts 3.8 months, from around Feb 18 to Jun 14. The brightest month is April, averaging about 5.2 kWh/m² (bright).
The dimmest month is December, down near 3.1 kWh/m² — roughly 40% less than the April peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 3.1 | 4.0 | 4.9 | 5.2 | 4.9 | 4.1 | 3.9 | 4.3 | 4.4 | 4.0 | 3.5 | 3.1 |
| Level | Moderate | Moderate | Bright | Bright | Bright | Bright | Moderate | Bright | Bright | Moderate | Moderate | Moderate |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 3.1 | Moderate |
| Feb | 4.0 | Moderate |
| Mar | 4.9 | Bright |
| Apr | 5.2 | Bright |
| May | 4.9 | Bright |
| Jun | 4.1 | Bright |
| Jul | 3.9 | Moderate |
| Aug | 4.3 | Bright |
| Sep | 4.4 | Bright |
| Oct | 4.0 | Moderate |
| Nov | 3.5 | Moderate |
| Dec | 3.1 | Moderate |
Where is Mường Lay?
Mường Lay sits at 22.0°N, 103.1°E, 496 m above sea level, in Vietnam. The nearest listed city is Lai Châu, 55 km away.
Topography around Mường Lay
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Mường Lay.
Within 3 km, the terrain around Mường Lay has large variations in elevation — a maximum elevation change of 987 m around an average of 501 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,867 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,950 m.
The land around Mường Lay is covered by trees (78%) within 3 km, trees (80%) within 16 km, and trees (80%) 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 Mường Lay (22°, 103.1333°, elevation 496 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. 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).