San Antonio in Summer
In summer (December, January and February), San Antonio sees average daytime highs around 22°C and overnight lows near 15°C, with 128 mm of rain over about 29 wet days across the season. It is the 3rd-warmest season and the wettest season of the year.
Across summer, daytime highs hold fairly steady around 22°C. The sky is clear or mostly clear about 11% of the time across summer, and the air most often feels dry.
Summer is San Antonio's weakest season of the year to visit on our travel score. For the whole year in context, see San Antonio's year-round climate.
- Avg daytime high
- 22°C
- 3rd-warmest season
- Avg overnight low
- 15°C
- Rainfall
- 128 mm
- 29 wet days
- Avg wind
- 7 km/h
- Travel score
- 6.4
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in San Antonio in Summer
Across summer, daytime highs hold fairly steady around 22°C.
A typical summer day in San Antonio reaches about 22°C and drops to 15°C overnight. The warmest of the three months is December, the coolest December.
San Antonio 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 | 22° / 15° | 52 | 12 | 12.9 | 6.0 |
| Feb | 22° / 15° | 63 | 13.2 | 12.6 | 5.6 |
| Mar | 22° / 15° | 41 | 10.2 | 12.1 | 6.3 |
| Apr | 23° / 15° | 9 | 2.1 | 11.6 | 8.2 |
| May | 23° / 14° | 1 | 0.2 | 11.2 | 9.1 |
| Jun | 22° / 13° | 0 | 0.1 | 11 | 9.0 |
| Jul | 22° / 13° | 0 | 0.2 | 11.1 | 9.0 |
| Aug | 22° / 13° | 1 | 0.3 | 11.4 | 9.1 |
| Sep | 23° / 14° | 1 | 0.2 | 11.9 | 9.2 |
| Oct | 23° / 15° | 1 | 0.2 | 12.4 | 8.8 |
| Nov | 23° / 15° | 2 | 0.6 | 12.8 | 8.5 |
| Dec | 23° / 15° | 13 | 3.3 | 13 | 7.6 |
Cloud cover in Summer
The sky is clear or mostly clear about 11% of the time across summer.
Chance of precipitation in Summer
San Antonio gets around 128 mm of rain over 29 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 7 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 13 hours in early December to 12 h 24 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 7.0 kWh/m².
Is summer a good time to visit San Antonio?
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 reasonable time to visit San Antonio for sightseeing.
What to pack for San Antonio in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, San Antonio sees daytime highs around 22°C and nights near 15°C. Pack rain gear and sun protection. Worth having: light clothes. About 29 days see rain.
Sea temperature near San Antonio in Summer
The nearest coast averages about 21°C across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 51 km away) is warmest in February at about 22°C and coldest in August near 17°C.
It's comfortable for a long swim from Dec 3 to Apr 19 — about 4.5 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 22 | 22 | 21 | 20 | 19 | 18 | 17 | 17 | 17 | 18 | 19 | 21 |
| Comfort | Refreshing | Refreshing | Refreshing | Refreshing | Cool | Cool | Cool | Cool | Cool | Cool | Cool | Refreshing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 22 | Refreshing |
| Feb | 22 | Refreshing |
| Mar | 21 | Refreshing |
| Apr | 20 | Refreshing |
| May | 19 | Cool |
| Jun | 18 | Cool |
| Jul | 17 | Cool |
| Aug | 17 | Cool |
| Sep | 17 | Cool |
| Oct | 18 | Cool |
| Nov | 19 | Cool |
| Dec | 21 | Refreshing |
UV index in San Antonio in Summer
Clear-sky midday UV across summer averages around 17 (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 Antonio peaks around February 8 at about 18 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 23 at about 9 (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) | 18 | 18 | 15 | 13 | 10 | 9 | 9 | 11 | 13 | 16 | 15 | 16 |
| Level | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | Very high | Extreme | Extreme | Extreme | Extreme | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 18 | Extreme |
| Feb | 18 | Extreme |
| Mar | 15 | Extreme |
| Apr | 13 | Extreme |
| May | 10 | Extreme |
| Jun | 9 | Very high |
| Jul | 9 | Very high |
| Aug | 11 | Extreme |
| Sep | 13 | Extreme |
| Oct | 16 | Extreme |
| Nov | 15 | Extreme |
| Dec | 16 | Extreme |
Where is San Antonio?
San Antonio sits at 17.2°S, 70.9°W, 1,455 m above sea level, in Peru. The nearest listed city is Moquegua, 2.0 km away.
Topography around San Antonio
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Antonio.
Within 3 km, the terrain around San Antonio has significant variations in elevation — a maximum elevation change of 466 m around an average of 1,486 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,183 m; within 80 km, extreme variations in elevation — a maximum elevation change of 5,786 m.
The land around San Antonio is covered by bare terrain (64%) within 3 km, bare terrain (90%) within 16 km, and bare terrain (76%) within 80 km.
Peru travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type A / B / C
- 220 V · 60 Hz
- Prices
- ≈ 51% of US
- price level, 2025
- GDP per capita
- $9,684
- 2025
- Happiness
- 6.0 / 10
- World Happiness, 2025
- Safe drinking water
- 49%
- of population, 2024
- Homicide rate
- 8.6
- per 100k, 2021
- Road deaths
- 13.6
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- Moderate
- EF EPI 519
- 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 Antonio (-17.2172°, -70.9259°, elevation 1,455 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.