San Luis in Summer
In summer (December, January and February), San Luis sees average daytime highs around 28°C and overnight lows near 17°C, with 290 mm of rain over about 37 wet days across the season. It is the warmest season of the year and the wettest season of the year.
Across summer, daytime highs hold fairly steady around 28°C. The sky is clear or mostly clear about 53% of the time across summer, and the air most often feels dry.
Summer is San Luis's weakest season of the year to visit on our travel score. For the whole year in context, see San Luis's year-round climate.
- Avg daytime high
- 28°C
- warmest season of the year
- Avg overnight low
- 17°C
- Rainfall
- 290 mm
- 37 wet days
- Avg wind
- 11 km/h
- Travel score
- 5.8
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in San Luis in Summer
Across summer, daytime highs hold fairly steady around 28°C.
A typical summer day in San Luis reaches about 28°C and drops to 17°C overnight. The warmest of the three months is January, the coolest December.
San Luis 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 | 29° / 18° | 107 | 13.3 | 14 | 5.3 |
| Feb | 28° / 17° | 81 | 10.9 | 13.2 | 6.3 |
| Mar | 26° / 15° | 80 | 10.1 | 12.3 | 7.1 |
| Apr | 22° / 11° | 53 | 7 | 11.2 | 7.4 |
| May | 18° / 8° | 25 | 4.2 | 10.3 | 6.8 |
| Jun | 16° / 5° | 8 | 1.9 | 9.8 | 6.3 |
| Jul | 16° / 4° | 9 | 2.1 | 10 | 6.1 |
| Aug | 18° / 6° | 15 | 2.6 | 10.8 | 7.4 |
| Sep | 21° / 9° | 30 | 4.6 | 11.8 | 7.6 |
| Oct | 24° / 12° | 66 | 8.7 | 12.8 | 7.5 |
| Nov | 26° / 14° | 89 | 11.7 | 13.7 | 6.7 |
| Dec | 28° / 17° | 102 | 13.1 | 14.2 | 5.8 |
Cloud cover in Summer
The sky is clear or mostly clear about 53% of the time across summer.
Chance of precipitation in Summer
San Luis gets around 290 mm of rain over 37 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 11 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 hours in early December to 12 h 48 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 7.2 kWh/m².
Hazard calendar for San Luis
In summer, San Luis overlaps its rainy season season. The full year is below, with each hazard's peak months called out.
San Luis's rainy season runs October–April, when most of the year's rain falls.
Is summer a good time to visit San Luis?
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 Luis for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for San Luis in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, San Luis sees daytime highs around 28°C and nights near 17°C. Pack light clothes and sun protection. Worth having: rain gear. About 37 days see rain.
UV index in San Luis in Summer
Clear-sky midday UV across summer averages around 13 (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 Luis peaks around January 17 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 21 at about 3 (moderate).
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) | 14 | 13 | 10 | 6 | 4 | 3 | 3 | 4 | 6 | 10 | 12 | 13 |
| Level | Extreme | Extreme | Extreme | High | Moderate | Moderate | Moderate | Moderate | High | Very high | Extreme | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 14 | Extreme |
| Feb | 13 | Extreme |
| Mar | 10 | Extreme |
| Apr | 6 | High |
| May | 4 | Moderate |
| Jun | 3 | Moderate |
| Jul | 3 | Moderate |
| Aug | 4 | Moderate |
| Sep | 6 | High |
| Oct | 10 | Very high |
| Nov | 12 | Extreme |
| Dec | 13 | Extreme |
Where is San Luis?
San Luis sits at 33.3°S, 66.3°W, 729 m above sea level, in Argentina. The nearest listed city is Villa Mercedes, 91 km away.
Topography around San Luis
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Luis.
Within 3 km, the terrain around San Luis has only modest variations in elevation — a maximum elevation change of 121 m around an average of 743 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,416 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,820 m.
The land around San Luis is covered by artificial surfaces (72%) within 3 km, shrubs (50%) and grassland (24%) within 16 km, and shrubs (59%) and grassland (22%) within 80 km.
Argentina travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type C / I
- 220 V · 50 Hz
- Prices
- ≈ 46% of US
- price level, 2025
- GDP per capita
- $14,898
- 2025
- Happiness
- 6.4 / 10
- World Happiness, 2025
- Homicide rate
- 4.5
- per 100k, 2023
- Road deaths
- 14.1
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- High
- EF EPI 575
- 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 Luis (-33.2914°, -66.3247°, elevation 729 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.