Climate and average weather in San Borja

In San Borja, the weather is humid, hot, wet, and partly cloudy and remarkably steady, with daytime highs holding near hot levels all year. The wettest stretch peaks around January.

Best: mid May to early August

Over the course of the year, the temperature in San Borja typically varies from 18°C to 33°C, and is rarely below 12°C or above 38°C. September is the hottest month of the year, while June is the coldest.

Based on the travel score, the best time of year to visit San Borja for warm-weather activities is from mid May to early August.

Hottest
Sep
33°
Coldest
Jun
19°
Wettest
Jan
348 mm
Driest
Jul
49 mm
Rain / yr
2125 mm
196 wet days
Daylight
11.1–12.9 h
shortest–longest
Elevation
195 m
14.9°S
Clearest
Aug
44% cloud

San Borja is Municipio en Bolivia.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

San Borja 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 mid May to early August.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

Temperatures in San Borja stay fairly even through the year, without a distinct hot or cool season. The warmest month is September, with an average high of 33°C and low of 21°C; the coolest is June, with an average low of 19°C and high of 28°C.

Days typically run about 9°C warmer than nights, with the widest day–night swing (around 12°C) in August.

10°15°20°25°30°35°40°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan3123
Feb3123
Mar3123
Apr3022
May2920
Jun2819
Jul2818
Aug3119
Sep3321
Oct3323
Nov3223
Dec3123

How hot and cold San Borja 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, San Borja feels like about 37°C (around October 20). About 261 days a year carry some heat stress, peaking in October.

15°20°25°30°35°40°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan36312323
Feb36312323
Mar36312323
Apr34302222
May30292020
Jun29281919
Jul29281818
Aug32311919
Sep35332121
Oct36332323
Nov36322323
Dec36312323

Average hourly temperature in San Borja

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 September afternoons, near 33°C, and coldest before dawn in June, near 19°C.

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

San Borja 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
Jan31° / 23°34827.112.82.7
Feb31° / 23°30323.312.52.9
Mar31° / 23°2652412.13.0
Apr30° / 22°15416.711.73.9
May29° / 20°8611.311.35.5
Jun28° / 19°577.611.16.5
Jul28° / 18°496.211.26.5
Aug31° / 19°60711.54.9
Sep33° / 21°11810.811.93.6
Oct33° / 23°17817.612.33.0
Nov32° / 23°21219.412.73.0
Dec31° / 23°29424.612.92.8

Chance of rain

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

San Borja gets about 2125 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 6.0 months, from around Oct 14 to Apr 15, peaking in January at about 88% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jul 26.

January is the wettest month by volume, with 348 mm over about 27 wet days; July is the driest, with 49 mm.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetJan 8 · 88%Jul 26 · 17%
Rain on a day (%)Rain days
Jan8627
Feb8423
Mar7824
Apr5517
May3711
Jun268
Jul206
Aug237
Sep3611
Oct5518
Nov6519
Dec7925

Monthly rainfall

Over a full year, San Borja collects about 2125 mm of rain across 196 wet days — roughly 177 mm in an average month.

It doesn’t fall evenly. January is the wettest month with 348 mm, while July is the driest at just 49 mm. The three wettest months alone bring about 45% of the year’s total.

050100150200250300350400JanFebMarAprMayJunJulAugSepOctNovDec34830326515486574960118178212294
Rainfall (mm)Rain days
Jan34827
Feb30323
Mar26524
Apr15417
May8611
Jun578
Jul496
Aug607
Sep11811
Oct17818
Nov21219
Dec29425

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In San Borja, 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 April 23 and lasts for 5.7 months, ending around October 11. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 69% of the time on average.

The cloudier part of the year begins around October 12 and lasts for 6.3 months, ending around April 22. The cloudiest month is January, 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%JanFebMarAprMayJunJulAugSepOctNovDecAug 14 · 70%Jan 12 · 10%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan1090
Feb1189
Mar1882
Apr3367
May4555
Jun5743
Jul6634
Aug6931
Sep5545
Oct3268
Nov2179
Dec1288

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 January 1, brings about 12 h 54 min of light; the shortest, around June 9, only 11 h 06 min — a swing of roughly 1 h 48 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan12.86:137:00
Feb12.56:276:56
Mar12.16:346:40
Apr11.76:376:17
May11.36:446:03
Jun11.16:536:01
Jul11.26:576:09
Aug11.56:466:16
Sep11.96:246:19
Oct12.36:026:22
Nov12.75:516:33
Dec12.95:576:49

Sunny days

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

San Borja averages about 6 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 1 and 16 days.

The sunnier stretch runs 5.1 months, from around May 4 to Oct 4. The sunniest month is August, with roughly 16 sunny days (bright).

The greyest month is January, down near 1 sunny days — about 94% fewer than the August peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightAug 1616 daysJan 31 days
Sunny daysSky
Jan1Gloomy
Feb1Gloomy
Mar2Gloomy
Apr4Gloomy
May8Gloomy
Jun11Mixed
Jul15Mixed
Aug16Bright
Sep10Mixed
Oct5Gloomy
Nov2Gloomy
Dec1Gloomy

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 San Borja, how humid it feels changes noticeably over the year.

The more humid part of the year lasts 7.2 months, from around September 27 to May 2. The muggiest month is January, when the air feels humid, muggy or worse about 100% of the time.

The most comfortable stretch runs from around May 3 to September 26, and July is the most comfortable month — the air is dry or comfortable 23% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJul 23 · 26%Jan 1 · 0%miserablemuggyoppressivehumidcomfortabledryhumidcomfortablehumid
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan00015148
Feb00135344
Mar00054846
Apr125134732
May281522476
Jun791627410
Jul13111834240
Aug11111933250
Sep571230451
Oct01617669
Nov003106025
Dec00135838

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 San Borja is steady company: average speeds sit near 8 km/hcalm — in every month of the year, with no meaningful windy or calm season.

051015JanFebMarAprMayJunJulAugSepOctNovDeccalmlight breezeDec 11 · 8 km/hMar 27 · 7 km/h
Wind speed (km/h)Feels
Jan8calm
Feb7calm
Mar7calm
Apr7calm
May7calm
Jun8calm
Jul8calm
Aug8calm
Sep8calm
Oct8calm
Nov8calm
Dec8calm

Hazard calendar for San Borja

In seasonPeak

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

San Borja's rainy season runs October–March, when most of the year's rain falls.

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

Best time to visit San Borja

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around late May, San Borja 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 San Borja for general outdoor tourist activities is from mid May to early August, with a peak score in the first week of July.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationJul 4 · 6.8

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
Jan2.7poor
Feb2.9poor
Mar3.0poor
Apr4.0fair
May5.5good
Jun6.4good
Jul6.5good
Aug4.9fair
Sep3.6fair
Oct3.0poor
Nov3.0poor
Dec2.8poor

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit San Borja for hot-weather activities is from early May to mid September, with a peak score in the last week of July.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 26 · 7.9

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 San Borja, 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.

San Borja packs about the same all year — highs hold near 33°C. Across the year the things worth having are light clothes, rain gear and sun protection.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In September, San Borja sees daytime highs around 33°C and nights near 21°C. Pack light clothes. Worth having: rain gear and sun protection. About 11 days see rain.

UV index (midday) in San Borja 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 San Borja peaks around January 21 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near September 11 at about 8 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeJan 21UV 15Sep 11UV 8
UV index (midday)Level
Jan16Extreme
Feb15Extreme
Mar14Extreme
Apr11Extreme
May9Very high
Jun8Very high
Jul8Very high
Aug8Very high
Sep8Very high
Oct12Extreme
Nov14Extreme
Dec13Extreme

Average hourly UV index in San Borja

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 January the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 7 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)
Jan8.57
Feb8.57
Mar86.5
Apr7.55.5
May6.54.5
Jun6.53.5
Jul6.53.5
Aug74
Sep6.54
Oct86
Nov8.56.5
Dec8.56.5

Air quality in San Borja 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 San Borja is worst in September — around 50 µg/m³ PM2.5 (poor), about 6.4× the cleanest month (May, 8 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecGoodModeratePoorModerateSep 2350 µg/m³May 218 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb12Good
Mar11Good
Apr9Good
May8Good
Jun8Good
Jul11Good
Aug22Moderate
Sep50Poor
Oct50Poor
Nov27Moderate
Dec11Good
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

San Borja 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. San Borja banks about 5,820 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around October.

02,0004,0006,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan529
Feb471
Mar522
Apr484
May441
Jun400
Jul405
Aug468
Sep506
Oct545
Nov518
Dec532

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.

San Borja receives about 4.7 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.6 and 5.6 kWh/m².

The brighter stretch of the year lasts 6.1 months, from around Aug 11 to Feb 11. The brightest month is October, averaging about 5.5 kWh/m² (bright).

The dimmest month is May, down near 3.9 kWh/m² — roughly 30% less than the October peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecbrighterdimmerbrighterdimmoderatebrightintenseOct 85.6 kWhMay 293.6 kWh
Solar energy (kWh/m²)Level
Jan4.9Bright
Feb4.7Bright
Mar4.7Bright
Apr4.5Bright
May3.8Moderate
Jun3.7Moderate
Jul4.0Bright
Aug4.8Bright
Sep5.4Bright
Oct5.5Bright
Nov5.3Bright
Dec5.0Bright

Where is San Borja?

San Borja sits at 14.9°S, 66.7°W, 195 m above sea level, in Bolivia. The nearest listed city is Caranavi, 140 km away.

CaranaviTrinidadSorataLa PazQuimeAchocallaLajaViacha

Topography around San Borja

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

Within 3 km, the terrain around San Borja has only modest variations in elevation — a maximum elevation change of 21 m around an average of 194 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 44 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,527 m.

The land around San Borja is covered by grassland (61%) and trees (28%) within 3 km, grassland (63%) and trees (30%) within 16 km, and trees (75%) and grassland (23%) within 80 km.

3 km
21 m
16 km
44 m
80 km
1,527 m
treesshrubsgrasslandartificial surfaceswaterwetland
Nearby: Caranavi 140 km · Trinidad 198 km · Sorata 228 km · La Paz 237 km · Quime 242 km · Achocalla 243 km · Laja 256 km · Viacha 260 km

Bolivia travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / B / C
230 V · 50 Hz
Prices
≈ 40% of US
price level, 2025
GDP per capita
$5,148
2025
Happiness
5.8 / 10
World Happiness, 2025
Homicide rate
4.4
per 100k, 2023
Road deaths
21.1
per 100k/yr, 2019
Income group
Lower middle
World Bank
English
Moderate
EF EPI 521
Religion
Roman Catholic 65%Protestant 20%none 6%other 5%

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 San Borja (-14.852°, -66.7495°, elevation 195 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).