Climate and average weather in San Luis
In San Luis, the summers are sweltering, dry, and clear and the winters are mild and mostly clear.
Over the course of the year, the temperature in San Luis typically varies from 48°F to 106°F, and is rarely below 40°F or above 112°F. July is the hottest month of the year, while December is the coldest.
Based on the travel score, the best time of year to visit San Luis for warm-weather activities is from late October to early April.
- Hottest
- Jul
- 106°
- Coldest
- Dec
- 48°
- Wettest
- Sep
- 0.5 in
- Driest
- Jun
- 0.0 in
- Rain / yr
- 3.3 in
- 16 wet days
- Daylight
- 9.9–14.1 h
- shortest–longest
- Elevation
- 131 ft
- 32.5°N
- Clearest
- Jun
- 10% cloud
San Luis is city in Yuma County, Arizona, United States.
- Density
- 356/km²
- people per km²
- Founded
- 1930
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
San Luis 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 late October to early April.
Temperature through the year
Daily average highs and lows in San Luis, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
The hot season lasts 4.2 months, from May 27 to September 30, with daily high temperatures above 97°F. The hottest month of the year in San Luis is July, with an average high of 106°F and low of 83°F.
The cool season lasts 3.1 months, from November 23 to February 23, with daily high temperatures below 76°F. The coldest month of the year in San Luis is December, with an average low of 48°F and high of 69°F.
Days typically run about 24°F warmer than nights, with the widest day–night swing (around 27°F) in June.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 71 | 74 | 81 | 87 | 95 | 103 | 106 | 106 | 101 | 91 | 78 | 69 |
| Avg low (°F) | 49 | 52 | 56 | 61 | 68 | 75 | 83 | 84 | 78 | 67 | 56 | 48 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| Jan | 71 | 49 |
| Feb | 74 | 52 |
| Mar | 81 | 56 |
| Apr | 87 | 61 |
| May | 95 | 68 |
| Jun | 103 | 75 |
| Jul | 106 | 83 |
| Aug | 106 | 84 |
| Sep | 101 | 78 |
| Oct | 91 | 67 |
| Nov | 78 | 56 |
| Dec | 69 | 48 |
How hot and cold San Luis really feels
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 Luis feels like about 109°F (around August 15). About 180 days a year carry some heat stress, and 90 of them tip into dangerous heat (feels-like above 102°F), peaking in August.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels-like high (°F) | 71 | 75 | 81 | 87 | 95 | 103 | 108 | 109 | 101 | 91 | 78 | 69 |
| Air high (°F) | 71 | 74 | 81 | 87 | 95 | 103 | 106 | 106 | 101 | 91 | 78 | 69 |
| Feels-like low (°F) | 47 | 52 | 56 | 61 | 68 | 75 | 83 | 84 | 78 | 66 | 56 | 46 |
| Air low (°F) | 49 | 52 | 56 | 61 | 68 | 75 | 83 | 84 | 78 | 67 | 56 | 48 |
| Feels-like high (°F) | Air high (°F) | Feels-like low (°F) | Air low (°F) | |
|---|---|---|---|---|
| Jan | 71 | 71 | 47 | 49 |
| Feb | 75 | 74 | 52 | 52 |
| Mar | 81 | 81 | 56 | 56 |
| Apr | 87 | 87 | 61 | 61 |
| May | 95 | 95 | 68 | 68 |
| Jun | 103 | 103 | 75 | 75 |
| Jul | 108 | 106 | 83 | 83 |
| Aug | 109 | 106 | 84 | 84 |
| Sep | 101 | 101 | 78 | 78 |
| Oct | 91 | 91 | 66 | 67 |
| Nov | 78 | 78 | 56 | 56 |
| Dec | 69 | 69 | 46 | 48 |
Average hourly temperature in San Luis
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 July afternoons, near 106°F, and coldest before dawn in December, near 48°F.
San Luis weather by month
Every month at a glance. Click a month for its detailed page.
| 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 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
San Luis gets about 3.3 in of precipitation a year. On a typical day the chance of rain is mostly dry, but that rises and falls sharply with the seasons.
The wetter season lasts 2.6 months, from around Jul 9 to Sep 24, peaking in September at about 12% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jun 15.
September is the wettest month by volume, with 0.5 in over about 2 wet days; June is the driest, with 0.0 in.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 5 | 8 | 5 | 2 | 1 | 1 | 5 | 9 | 7 | 3 | 3 | 5 |
| Rain days | 2 | 2 | 2 | 1 | 0 | 0 | 2 | 3 | 2 | 1 | 1 | 2 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 5 | 2 |
| Feb | 8 | 2 |
| Mar | 5 | 2 |
| Apr | 2 | 1 |
| May | 1 | 0 |
| Jun | 1 | 0 |
| Jul | 5 | 2 |
| Aug | 9 | 3 |
| Sep | 7 | 2 |
| Oct | 3 | 1 |
| Nov | 3 | 1 |
| Dec | 5 | 2 |
Monthly rainfall
Over a full year, San Luis collects about 3.3 in of rain across 16 wet days — roughly 0.3 in in an average month.
It doesn’t fall evenly. September is the wettest month with 0.5 in, while June is the driest at just 0.0 in. The three wettest months alone bring about 44% of the year’s total.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (in) | 0.4 | 0.5 | 0.4 | 0.1 | 0.0 | 0.0 | 0.2 | 0.4 | 0.5 | 0.2 | 0.2 | 0.4 |
| Rain days | 2 | 2 | 2 | 1 | 0 | 0 | 2 | 3 | 2 | 1 | 1 | 2 |
| Rainfall (in) | Rain days | |
|---|---|---|
| Jan | 0.4 | 2 |
| Feb | 0.5 | 2 |
| Mar | 0.4 | 2 |
| Apr | 0.1 | 1 |
| May | 0.0 | 0 |
| Jun | 0.0 | 0 |
| Jul | 0.2 | 2 |
| Aug | 0.4 | 3 |
| Sep | 0.5 | 2 |
| Oct | 0.2 | 1 |
| Nov | 0.2 | 1 |
| Dec | 0.4 | 2 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In San Luis, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.
The clearer part of the year begins around April 6 and lasts for 7.1 months, ending around November 7. The clearest month is June, when the sky is clear, mostly clear, or partly cloudy 94% of the time on average.
The cloudier part of the year begins around November 8 and lasts for 4.9 months, ending around April 5. The cloudiest month is February, when it is overcast or mostly cloudy 26% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 75 | 74 | 80 | 88 | 90 | 94 | 88 | 91 | 94 | 91 | 82 | 75 |
| Cloudier (%) | 25 | 26 | 20 | 12 | 10 | 6 | 12 | 9 | 6 | 9 | 18 | 25 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 75 | 25 |
| Feb | 74 | 26 |
| Mar | 80 | 20 |
| Apr | 88 | 12 |
| May | 90 | 10 |
| Jun | 94 | 6 |
| Jul | 88 | 12 |
| Aug | 91 | 9 |
| Sep | 94 | 6 |
| Oct | 91 | 9 |
| Nov | 82 | 18 |
| Dec | 75 | 25 |
Daylight, sunrise and sunset
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 June 7, brings about 14 h 06 min of light; the shortest, around January 1, only 9 h 54 min — a swing of roughly 4 h 12 min.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 10.1 | 10.8 | 11.8 | 12.8 | 13.6 | 14.1 | 13.9 | 13.2 | 12.2 | 11.2 | 10.3 | 9.9 |
| Sunrise (AM) | 7:46 | 7:29 | 6:56 | 6:15 | 5:46 | 5:36 | 5:46 | 6:07 | 6:28 | 6:49 | 7:15 | 7:39 |
| Sunset (PM) | 5:51 | 6:18 | 6:41 | 7:03 | 7:25 | 7:43 | 7:43 | 7:19 | 6:39 | 6:00 | 5:33 | 5:32 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 10.1 | 7:46 | 5:51 |
| Feb | 10.8 | 7:29 | 6:18 |
| Mar | 11.8 | 6:56 | 6:41 |
| Apr | 12.8 | 6:15 | 7:03 |
| May | 13.6 | 5:46 | 7:25 |
| Jun | 14.1 | 5:36 | 7:43 |
| Jul | 13.9 | 5:46 | 7:43 |
| Aug | 13.2 | 6:07 | 7:19 |
| Sep | 12.2 | 6:28 | 6:39 |
| Oct | 11.2 | 6:49 | 6:00 |
| Nov | 10.3 | 7:15 | 5:33 |
| Dec | 9.9 | 7:39 | 5:32 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
San Luis averages about 23 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 17 and 28 days.
The sunnier stretch runs 3.5 months, from around Apr 8 to Jul 22. The sunniest month is June, with roughly 27 sunny days (brilliant).
The greyest month is February, down near 18 sunny days — about 33% fewer than the June peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 19 | 17 | 21 | 23 | 26 | 27 | 25 | 25 | 26 | 26 | 22 | 20 |
| Sky | Bright | Bright | Bright | Brilliant | Brilliant | Brilliant | Brilliant | Brilliant | Brilliant | Brilliant | Bright | Bright |
| Sunny days | Sky | |
|---|---|---|
| Jan | 19 | Bright |
| Feb | 17 | Bright |
| Mar | 21 | Bright |
| Apr | 23 | Brilliant |
| May | 26 | Brilliant |
| Jun | 27 | Brilliant |
| Jul | 25 | Brilliant |
| Aug | 25 | Brilliant |
| Sep | 26 | Brilliant |
| Oct | 26 | Brilliant |
| Nov | 22 | Bright |
| Dec | 20 | Bright |
Humidity comfort
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 Luis, how humid it feels changes dramatically over the year.
The more humid part of the year lasts 3.4 months, from around June 24 to October 6. The muggiest month is August, when the air feels humid, muggy or worse about 72% of the time.
The most comfortable stretch runs from around October 7 to June 23, and January is the most comfortable month — the air is dry or comfortable 100% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 99 | 99 | 100 | 100 | 96 | 78 | 27 | 15 | 41 | 80 | 98 | 100 |
| Comfortable (%) | 1 | 1 | 0 | 0 | 3 | 13 | 19 | 13 | 14 | 10 | 2 | 0 |
| Humid (%) | 0 | 0 | 0 | 0 | 0 | 7 | 27 | 22 | 15 | 6 | 0 | 0 |
| Muggy (%) | 0 | 0 | 0 | 0 | 0 | 2 | 22 | 32 | 19 | 3 | 0 | 0 |
| Oppressive (%) | 0 | 0 | 0 | 0 | 0 | 0 | 6 | 16 | 11 | 1 | 0 | 0 |
| Miserable (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 0 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| Jan | 99 | 1 | 0 | 0 | 0 | 0 |
| Feb | 99 | 1 | 0 | 0 | 0 | 0 |
| Mar | 100 | 0 | 0 | 0 | 0 | 0 |
| Apr | 100 | 0 | 0 | 0 | 0 | 0 |
| May | 96 | 3 | 0 | 0 | 0 | 0 |
| Jun | 78 | 13 | 7 | 2 | 0 | 0 |
| Jul | 27 | 19 | 27 | 22 | 6 | 0 |
| Aug | 15 | 13 | 22 | 32 | 16 | 1 |
| Sep | 41 | 14 | 15 | 19 | 11 | 1 |
| Oct | 80 | 10 | 6 | 3 | 1 | 0 |
| Nov | 98 | 2 | 0 | 0 | 0 | 0 |
| Dec | 100 | 0 | 0 | 0 | 0 | 0 |
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 Luis is steady company: average speeds sit near 6 mph — calm — in every month of the year, with no meaningful windy or calm season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (mph) | 6 | 6 | 6 | 7 | 6 | 6 | 7 | 6 | 6 | 5 | 6 | 6 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (mph) | Feels | |
|---|---|---|
| Jan | 6 | calm |
| Feb | 6 | calm |
| Mar | 6 | calm |
| Apr | 7 | calm |
| May | 6 | calm |
| Jun | 6 | calm |
| Jul | 7 | calm |
| Aug | 6 | calm |
| Sep | 6 | calm |
| Oct | 5 | calm |
| Nov | 6 | calm |
| Dec | 6 | calm |
Best time to visit San Luis
To characterize how pleasant the weather is in San Luis throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around late March, San Luis is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.
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 64°F and 82°F. Based on this score, the best time of year to visit San Luis for general outdoor tourist activities is from late October to early April, with a peak score in the third week of November.
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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Travel score (0–10) | 8.4 | 8.6 | 8.1 | 6.1 | 3.5 | 0.8 | 0.0 | 0.0 | 1.2 | 5.0 | 8.5 | 8.2 |
| Rating | ideal | ideal | ideal | good | poor | poor | poor | poor | poor | fair | ideal | ideal |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 8.4 | ideal |
| Feb | 8.6 | ideal |
| Mar | 8.1 | ideal |
| Apr | 6.1 | good |
| May | 3.5 | poor |
| Jun | 0.8 | poor |
| Jul | 0.0 | poor |
| Aug | 0.0 | poor |
| Sep | 1.2 | poor |
| Oct | 5.0 | fair |
| Nov | 8.5 | ideal |
| Dec | 8.2 | ideal |
The beach/pool score favors clear, rainless days with daytime highs between 75°F and 93°F. Based on this score, the best times of year to visit San Luis for hot-weather activities run from late February to mid May and again from early October to late November, with a peak score in the first week of April.
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 Luis, by month
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.
For a warm-season trip around July (highs near 106°F), the essentials are light clothes and sun protection. In the cold season around December (highs near 69°F), pack a light layer.
In July, San Luis sees daytime highs around 106°F and nights near 83°F. Pack light clothes and sun protection.
UV index (midday) in San Luis by month
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 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 |
Average hourly UV index in San Luis
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 June the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 6 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV ≥ 3 (h/day) | 3.5 | 4.5 | 5 | 7 | 7.5 | 8.5 | 8.5 | 8 | 7 | 5.5 | 4 | 1.5 |
| UV ≥ 6 (h/day) | 0 | 0 | 0 | 4 | 4.5 | 6 | 6 | 5.5 | 4.5 | 1.5 | 0 | 0 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 3.5 | 0 |
| Feb | 4.5 | 0 |
| Mar | 5 | 0 |
| Apr | 7 | 4 |
| May | 7.5 | 4.5 |
| Jun | 8.5 | 6 |
| Jul | 8.5 | 6 |
| Aug | 8 | 5.5 |
| Sep | 7 | 4.5 |
| Oct | 5.5 | 1.5 |
| Nov | 4 | 0 |
| Dec | 1.5 | 0 |
Growing season
San Luis is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Frost-free chance (%) | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Frost nights | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Frost-free chance (%) | Frost nights | |
|---|---|---|
| Jan | 100 | 0 |
| Feb | 100 | 0 |
| Mar | 100 | 0 |
| Apr | 100 | 0 |
| May | 100 | 0 |
| Jun | 100 | 0 |
| Jul | 100 | 0 |
| Aug | 100 | 0 |
| Sep | 100 | 0 |
| Oct | 100 | 0 |
| Nov | 100 | 0 |
| Dec | 100 | 0 |
Growing degree days
Growing degree days tally heat above 50°F: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. San Luis banks about 9,712 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around August.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Growing degree days (°F·days) | 311 | 367 | 575 | 725 | 968 | 1,165 | 1,377 | 1,382 | 1,178 | 886 | 507 | 271 |
| Growing degree days (°F·days) | |
|---|---|
| Jan | 311 |
| Feb | 367 |
| Mar | 575 |
| Apr | 725 |
| May | 968 |
| Jun | 1,165 |
| Jul | 1,377 |
| Aug | 1,382 |
| Sep | 1,178 |
| Oct | 886 |
| Nov | 507 |
| Dec | 271 |
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 Luis receives about 6.1 kWh/m² a day of solar energy on average — intense — with a clear seasonal swing between 3.3 and 8.5 kWh/m².
The brighter stretch of the year lasts 6.4 months, from around Mar 14 to Sep 23. The brightest month is June, averaging about 8.4 kWh/m² (intense).
The dimmest month is December, down near 3.4 kWh/m² — roughly 60% less than the June peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 3.7 | 4.7 | 6.2 | 7.5 | 8.3 | 8.5 | 7.8 | 7.1 | 6.3 | 5.2 | 4.0 | 3.4 |
| Level | Moderate | Bright | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Bright | Moderate | Moderate |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 3.7 | Moderate |
| Feb | 4.7 | Bright |
| Mar | 6.2 | Intense |
| Apr | 7.5 | Intense |
| May | 8.3 | Intense |
| Jun | 8.5 | Intense |
| Jul | 7.8 | Intense |
| Aug | 7.1 | Intense |
| Sep | 6.3 | Intense |
| Oct | 5.2 | Bright |
| Nov | 4.0 | Moderate |
| Dec | 3.4 | 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. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).