San Luis in Summer
In summer (June, July and August), San Luis sees average daytime highs around 105°F and overnight lows near 80°F, with 0.6 in of rain over about 5 wet days across the season. It is the warmest season of the year and the 3rd-wettest season.
Over the season highs climb from about 99°F in early June to 104°F by late August. The sky is clear or mostly clear about 83% 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
- 105°F
- warmest season of the year
- Avg overnight low
- 80°F
- Rainfall
- 0.6 in
- 5 wet days
- Avg wind
- 6 mph
- Travel score
- 0.2
- weakest season of the year
- Months
- Jun · Jul · Aug
Temperature in San Luis in Summer
Over the season highs climb from about 99°F in early June to 104°F by late August.
A typical summer day in San Luis reaches about 105°F and drops to 80°F overnight. The warmest of the three months is July, the coolest June.
How summer really feels in San Luis
Once humidity and wind are folded in, summer brings about 92 days that feel above 90°F and 0 that feel at or below 32°F.
The story in summer is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
San Luis weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 71° / 49° | 0.4 | 1.5 | 10.1 | 8.4 |
| Feb | 74° / 52° | 0.5 | 2.3 | 10.8 | 8.6 |
| Mar | 81° / 56° | 0.4 | 1.5 | 11.8 | 8.1 |
| Apr | 87° / 61° | 0.1 | 0.6 | 12.8 | 6.1 |
| May | 95° / 68° | 0.0 | 0.2 | 13.6 | 3.5 |
| Jun | 103° / 75° | 0.0 | 0.2 | 14.1 | 0.7 |
| Jul | 106° / 83° | 0.2 | 1.5 | 13.9 | 0.0 |
| Aug | 106° / 84° | 0.4 | 2.9 | 13.2 | 0.0 |
| Sep | 101° / 78° | 0.5 | 2.2 | 12.2 | 1.2 |
| Oct | 91° / 67° | 0.2 | 0.9 | 11.2 | 4.9 |
| Nov | 78° / 56° | 0.2 | 0.8 | 10.3 | 8.6 |
| Dec | 69° / 48° | 0.4 | 1.7 | 9.9 | 8.2 |
Cloud cover in Summer
The sky is clear or mostly clear about 83% of the time across summer.
Chance of precipitation in Summer
San Luis gets around 0.6 in of rain over 5 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 6 mph across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 hours in early June to 12 h 42 min by late August. 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 7.8 kWh/m².
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 weaker month for outdoor sightseeing in San Luis.
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 105°F and nights near 80°F. Pack light clothes and sun protection. About 5 days see rain.
UV index in San Luis in Summer
Clear-sky midday UV across summer averages around 10 (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 June 23 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 18 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) | 4 | 5 | 5 | 8 | 8 | 11 | 11 | 10 | 9 | 6 | 4 | 3 |
| Level | Moderate | Moderate | Moderate | Very high | Very high | Extreme | Extreme | Very high | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 4 | Moderate |
| Feb | 5 | Moderate |
| Mar | 5 | Moderate |
| Apr | 8 | Very high |
| May | 8 | Very high |
| Jun | 11 | Extreme |
| Jul | 11 | Extreme |
| Aug | 10 | Very high |
| Sep | 9 | Very high |
| Oct | 6 | High |
| Nov | 4 | Moderate |
| Dec | 3 | Moderate |
Where is San Luis?
San Luis sits at 32.5°N, 114.8°W, 131 ft above sea level, in United States. The nearest listed city is San Luis Río Colorado, 2.5 mi away.
Topography around San Luis
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of San Luis.
Within 2 miles, the terrain around San Luis has only modest variations in elevation — a maximum elevation change of 89 ft around an average of 118 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 180 ft; within 50 miles, large variations in elevation — a maximum elevation change of 3,652 ft.
The land around San Luis is covered by artificial surfaces (46%), bare terrain (26%) and cropland (24%) within 2 miles, bare terrain (45%) and cropland (41%) within 10 miles, and bare terrain (73%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- 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 (32.487°, -114.7822°, elevation 131 ft), 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.