Climate and average weather in Bo

In Bo, the summers are oppressive, hot, wet, and mostly cloudy and the winters are mild and mostly cloudy.

Best: early January to mid April

Over the course of the year, the temperature in Bo typically varies from 14°C to 32°C, and is rarely below 9°C or above 36°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 Bo for warm-weather activities are from early January to mid April and mid October to late December.

Hottest
Jun
32°
Coldest
Jan
14°
Wettest
Aug
393 mm
Driest
Feb
28 mm
Rain / yr
2048 mm
181 wet days
Daylight
10.7–13.3 h
shortest–longest
Elevation
67 m
20.7°N
Clearest
Nov
58% cloud

Bo 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

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Bo, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 5.4 months, from April 22 to October 1, with daily high temperatures above 29°C. The hottest month of the year in Bo is June, with an average high of 32°C and low of 26°C.

The cool season lasts 2.6 months, from December 6 to February 21, with daily high temperatures below 21°C. The coldest month of the year in Bo is January, with an average low of 14°C and high of 19°C.

Days typically run about 6°C warmer than nights year-round.

10°20°30°40°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan1914
Feb2115
Mar2418
Apr2821
May3124
Jun3226
Jul3226
Aug3125
Sep3024
Oct2721
Nov2418
Dec2114

How hot and cold Bo really feels

Feels-like highFeels-like lowactual air temp

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, Bo feels like about 41°C (around June 25). About 161 days a year carry some heat stress, and 72 of them tip into dangerous heat (feels-like above 39°C), peaking in June.

10°20°30°40°JanFebMarAprMayJunJulAugSepOctNovDecdangerous heat
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan19191314
Feb21211515
Mar24241818
Apr30282121
May36312424
Jun40322626
Jul40322626
Aug39312525
Sep35302424
Oct29272121
Nov24241818
Dec20211414

Average hourly temperature in Bo

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 32°C, and coldest before dawn in January, near 14°C.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Bo weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan19° / 14°448.510.96.0
Feb21° / 15°287.211.36.3
Mar24° / 18°5910.411.96.4
Apr28° / 21°11413.512.55.3
May31° / 24°27520.2133.4
Jun32° / 26°26721.113.22.7
Jul32° / 26°32023.613.12.7
Aug31° / 25°39326.412.72.7
Sep30° / 24°29021.112.13.6
Oct27° / 21°15614.711.55.6
Nov24° / 18°668.2117.0
Dec21° / 14°356.310.86.8

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Bo gets about 2048 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 5.7 months, from around Apr 23 to Oct 13, peaking in August at about 86% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Dec 17.

August is the wettest month by volume, with 393 mm over about 26 wet days; February is the driest, with 28 mm.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetAug 22 · 86%Dec 17 · 19%
Rain on a day (%)Rain days
Jan279
Feb267
Mar3410
Apr4514
May6520
Jun7021
Jul7724
Aug8526
Sep7121
Oct4715
Nov288
Dec216

Monthly rainfall

Over a full year, Bo collects about 2048 mm of rain across 181 wet days — roughly 171 mm in an average month.

It doesn’t fall evenly. August is the wettest month with 393 mm, while February is the driest at just 28 mm. The three wettest months alone bring about 49% of the year’s total.

050100150200250300350400450JanFebMarAprMayJunJulAugSepOctNovDec4428591142752673203932901566635
Rainfall (mm)Rain days
Jan449
Feb287
Mar5910
Apr11414
May27520
Jun26721
Jul32024
Aug39326
Sep29021
Oct15615
Nov668
Dec356

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Bo, 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 14 and lasts for 3.8 months, ending around January 8. 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 8 and lasts for 4.2 months, ending around September 13. The cloudiest month is June, when it is overcast or mostly cloudy 90% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecNov 4 · 52%Jun 18 · 9%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearer
Clearer (%)Cloudier (%)
Jan2476
Feb2278
Mar2278
Apr2773
May2179
Jun1090
Jul1288
Aug1585
Sep2971
Oct4654
Nov4852
Dec4159

Daylight, sunrise and sunset

DaylightNight

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 18, brings about 13 h 18 min of light; the shortest, around December 17, only 10 h 42 min — a swing of roughly 2 h 36 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan10.96:415:33
Feb11.36:345:51
Mar11.96:126:03
Apr12.55:446:12
May13.05:256:23
Jun13.25:216:35
Jul13.15:296:38
Aug12.75:416:23
Sep12.15:495:56
Oct11.55:575:28
Nov11.06:135:13
Dec10.86:315:17

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Bo averages about 5 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 1 and 10 days.

The sunnier stretch runs 3.9 months, from around Sep 14 to Jan 10. The sunniest month is November, with roughly 9 sunny days (mixed).

The greyest month is June, down near 1 sunny days — about 84% fewer than the November peak.

051015JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergloomymixedNov 310 daysJun 181 days
Sunny daysSky
Jan4Gloomy
Feb4Gloomy
Mar4Gloomy
Apr4Gloomy
May3Gloomy
Jun1Gloomy
Jul2Gloomy
Aug2Gloomy
Sep5Gloomy
Oct8Mixed
Nov9Mixed
Dec8Mixed

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

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 Bo, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 7.4 months, from around March 22 to November 1. 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 2 to March 21, and January is the most comfortable month — the air is dry or comfortable 68% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJan 22 · 70%May 10 · 0%oppressivehumidmuggymiserablecomfortabledrycomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan4721211200
Feb3420232030
Mar13152131190
Apr2512224415
May003103453
Jun0002989
Jul0000496
Aug00001090
Sep00294049
Oct251528437
Nov14202325180
Dec4025221220

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 Bo is steady company: average speeds sit near 6 km/hcalm — in every month of the year, with no meaningful windy or calm season.

0510JanFebMarAprMayJunJulAugSepOctNovDeccalmApr 19 · 6 km/hAug 4 · 5 km/h
Wind speed (km/h)Feels
Jan6calm
Feb6calm
Mar6calm
Apr6calm
May6calm
Jun5calm
Jul5calm
Aug5calm
Sep5calm
Oct6calm
Nov6calm
Dec6calm

Hazard calendar for Bo

In seasonPeak

When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.

Bo's monsoon runs May–September, when most of the year's rain falls.

Monsoon
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Best time to visit Bo

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Bo throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around mid January, Bo 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 Bo for general outdoor tourist activities is from mid October to mid April, with a peak score in the third week of November.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationNov 17 · 7.1

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).

Travel score (0–10)Rating
Jan6.0good
Feb6.4good
Mar6.4good
Apr5.3fair
May3.4poor
Jun2.7poor
Jul2.7poor
Aug2.7poor
Sep3.6fair
Oct5.6good
Nov7.0good
Dec6.8good

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 Bo for hot-weather activities run from mid March to mid May and again from late September to late November, with a peak score in the first week of November.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timebeach/pool scoretemperaturecloudsprecipitationNov 5 · 6.4

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 Bo, by month

EssentialRecommendedOptional

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 32°C), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 19°C), pack rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In June, Bo sees daytime highs around 32°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 21 days see rain.

UV index (midday) in Bo by month

LowModerateHighVery highExtreme

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 Bo peaks around June 20 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 22 at about 6 (high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highHighExtremeVery highHighJun 20UV 11Nov 22UV 6
UV index (midday)Level
Jan6High
Feb7High
Mar9Very high
Apr6High
May7High
Jun12Extreme
Jul10Extreme
Aug10Extreme
Sep7High
Oct8Very high
Nov6High
Dec6High

Average hourly UV index in Bo

LowModerateHighVery highExtreme

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 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan5.51.5
Feb63
Mar74.5
Apr6.51.5
May73.5
Jun8.56
Jul85.5
Aug85.5
Sep6.53
Oct6.53.5
Nov5.50
Dec5.50.5

Air quality in Bo by month

GoodModeratePoorUnhealthyVery unhealthy

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 Bo is worst in December — around 171 µg/m³ PM2.5 (very unhealthy), about 3.4× the cleanest month (July, 50 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0306090120150180JanFebMarAprMayJunJulAugSepOctNovDecVery unhealthyUnhealthyPoorUnhealthyVery unhealthyDec 19170 µg/m³Jul 1452 µg/m³
PM2.5 (µg/m³)Level
Jan161Very unhealthy
Feb136Unhealthy
Mar122Unhealthy
Apr106Unhealthy
May76Unhealthy
Jun59Unhealthy
Jul50Poor
Aug68Unhealthy
Sep96Unhealthy
Oct125Unhealthy
Nov152Very unhealthy
Dec171Very unhealthy
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Bo is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecfrost-free year round
Frost-free chance (%)Frost nights
Jan1000
Feb1000
Mar1000
Apr1000
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov1000
Dec1000

Growing degree days

Degree days (base 10°C)Frost-free shaded

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. Bo banks about 4,917 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around June.

02,0004,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan192
Feb218
Mar328
Apr434
May534
Jun564
Jul577
Aug557
Sep503
Oct445
Nov334
Dec231

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.

Bo receives about 3.8 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 2.2 and 5.0 kWh/m².

The brighter stretch of the year lasts 6.4 months, from around Apr 6 to Oct 17. The brightest month is June, averaging about 4.9 kWh/m² (bright).

The dimmest month is January, down near 2.3 kWh/m² — roughly 53% less than the June peak.

0123456JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightJun 295.0 kWhJan 162.2 kWh
Solar energy (kWh/m²)Level
Jan2.3Moderate
Feb2.6Moderate
Mar3.1Moderate
Apr4.2Bright
May4.9Bright
Jun5.0Bright
Jul4.8Bright
Aug4.5Bright
Sep4.2Bright
Oct3.8Moderate
Nov3.2Moderate
Dec2.6Moderate

Where is Bo?

Bo sits at 20.7°N, 105.5°E, 67 m above sea level, in Vietnam. The nearest listed city is Xuân Mai, 26 km away.

Topography around Bo

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Bo.

Within 3 km, the terrain around Bo has significant variations in elevation — a maximum elevation change of 427 m around an average of 122 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,185 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,622 m.

The land around Bo is covered by trees (71%) and cropland (23%) within 3 km, trees (86%) within 16 km, and trees (60%) and cropland (27%) within 80 km.

3 km
427 m
16 km
1,185 m
80 km
1,622 m
treesgrasslandcroplandartificial surfaceswater
Nearby: Xuân Mai 26 km · Hòa Bình 26 km · Phủ Lý 42 km · Hà Đông 42 km · Dại Mỗ 42 km · Vinhomes Smart City 43 km · Tây Mỗ 43 km · Thanh Liệt 44 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
none 86%Catholic 6%Buddhist 6%Protestant 1%

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 Bo (20.6726°, 105.5362°, elevation 67 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).