San Borja in Summer
In summer (December, January and February), San Borja sees average daytime highs around 31°C and overnight lows near 23°C, with 946 mm of rain over about 75 wet days across the season. It is the 2nd-warmest season and the wettest season of the year.
Across summer, daytime highs hold fairly steady around 31°C. The sky is clear or mostly clear about 4% of the time across summer, and the air most often feels oppressive.
Summer is San Borja's weakest season of the year to visit on our travel score. For the whole year in context, see San Borja's year-round climate.
- Avg daytime high
- 31°C
- 2nd-warmest season
- Avg overnight low
- 23°C
- Rainfall
- 946 mm
- 75 wet days
- Avg wind
- 8 km/h
- Travel score
- 2.8
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in San Borja in Summer
Across summer, daytime highs hold fairly steady around 31°C.
A typical summer day in San Borja reaches about 31°C and drops to 23°C overnight. The warmest of the three months is December, the coolest February.
How summer really feels in San Borja
Once humidity and wind are folded in, summer brings about 90 days that feel above 32°C and 0 that feel at or below 0°C.
The story in summer is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
San Borja weather by month
How the three summer months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 31° / 23° | 348 | 27.1 | 12.8 | 2.7 |
| Feb | 31° / 23° | 303 | 23.3 | 12.5 | 2.9 |
| Mar | 31° / 23° | 265 | 24 | 12.1 | 3.0 |
| Apr | 30° / 22° | 154 | 16.7 | 11.7 | 3.9 |
| May | 29° / 20° | 86 | 11.3 | 11.3 | 5.5 |
| Jun | 28° / 19° | 57 | 7.6 | 11.1 | 6.5 |
| Jul | 28° / 18° | 49 | 6.2 | 11.2 | 6.5 |
| Aug | 31° / 19° | 60 | 7 | 11.5 | 4.9 |
| Sep | 33° / 21° | 118 | 10.8 | 11.9 | 3.6 |
| Oct | 33° / 23° | 178 | 17.6 | 12.3 | 3.0 |
| Nov | 32° / 23° | 212 | 19.4 | 12.7 | 3.0 |
| Dec | 31° / 23° | 294 | 24.6 | 12.9 | 2.8 |
Cloud cover in Summer
The sky is clear or mostly clear about 4% of the time across summer.
Chance of precipitation in Summer
San Borja gets around 946 mm of rain over 75 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 8 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 12 h 48 min in early December to 12 h 18 min by late February. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 4.9 kWh/m².
Hazard calendar for San Borja
In summer, San Borja overlaps its rainy season season. The full year is below, with each hazard's peak months called out.
San Borja's rainy season runs October–March, when most of the year's rain falls.
Is summer a good time to visit San Borja?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a weaker month for outdoor sightseeing in San Borja.
What to pack for San Borja in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, San Borja sees daytime highs around 31°C and nights near 23°C. Pack light clothes and rain gear. Worth having: sun protection. About 75 days see rain.
UV index in San Borja in Summer
Clear-sky midday UV across summer averages around 15 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 16 | 15 | 14 | 11 | 9 | 8 | 8 | 8 | 8 | 12 | 14 | 13 |
| Level | Extreme | Extreme | Extreme | Extreme | Very high | Very high | Very high | Very high | Very high | Extreme | Extreme | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 16 | Extreme |
| Feb | 15 | Extreme |
| Mar | 14 | Extreme |
| Apr | 11 | Extreme |
| May | 9 | Very high |
| Jun | 8 | Very high |
| Jul | 8 | Very high |
| Aug | 8 | Very high |
| Sep | 8 | Very high |
| Oct | 12 | Extreme |
| Nov | 14 | Extreme |
| Dec | 13 | Extreme |
Air quality in San Borja in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual 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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 11 | 12 | 11 | 9 | 8 | 8 | 11 | 22 | 50 | 50 | 27 | 11 |
| Level | Good | Good | Good | Good | Good | Good | Good | Moderate | Poor | Poor | Moderate | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 11 | Good |
| Feb | 12 | Good |
| Mar | 11 | Good |
| Apr | 9 | Good |
| May | 8 | Good |
| Jun | 8 | Good |
| Jul | 11 | Good |
| Aug | 22 | Moderate |
| Sep | 50 | Poor |
| Oct | 50 | Poor |
| Nov | 27 | Moderate |
| Dec | 11 | Good |
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.
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.
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
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.