San Luis, CO Climate: Temperature & Rain by Month
Temperature and precipitation from NOAA NCEI 1991–2020 normals →, plus PlainClimate's derived comfort score
30-year climate normals (1991-2020) from San Luis's primary NOAA station, SAN LUIS 1 S.
The climate verdict for San Luis
Dryness leads the climate profile for San Luis, Colorado, with 9.0 inches of precipitation a year. NOAA records an annual average of 44°F. At 28/100 (below average) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 0% of scores.
- 44°F
- average temperature, NOAA 1991-2020 normal
- 28/100
- comfort score, above 0% of station-mapped location scores
- 9.0"
- precipitation, annual total
- 115 days
- frost-free growing season
San Luis: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00057430 · San Luis, CO 44°F mean · 9.0" precip
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-ARID · SWING-MID · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 44°F
- RANK-COOL #1,029
- PHOTO-FINISH ≈ Donner Mem Stat…
- PRCP-ARID 9.0"
- SWING-MID 43°F
- COMF-LOW 28/100
- LOAD-HEAT 7,719 HDD
- STN-1 USC00057430
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Donner Mem State Park, CA (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every CO station list.
- San Luis (this station) 44°F
- Cold Mammoth Lakes R…, CA 44°F
- Hot Truckee Ranger…, CA 44°F
- Near Donner Mem Stat…, CA 44°F
- Near Hatch, UT 44°F
Climate Living Index · San Luis
San Luis: 10/100 · grade F
San Luis publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for San Luis, not an official NOAA rating. Rankings still use Comfort Score 28/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Annual temperature balance | 44.0°F · 23.5° from 67.5°F | 16/100 · F |
| Precipitation balance | 9.0 in · 26.0 from 35 in | 9/100 · F |
| Normal heat + freeze calendar | 214 calendar days | 7/100 · F |
| Frost-free season | 115 days/year | 5/100 · F |
San Luis · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
San Luis's normals sit in a dry climate class: BSk
Precipitation is low relative to temperature but above true desert thresholds: cold semi-arid steppe (BSk). Class BSk is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: dry (arid or semi-arid), specifically cold semi-arid steppe.
- Köppen code
- BSk
- Group
- Dry (arid or semi-arid)
- Warmest month
- 65.0°F
- Coldest month
- 21.6°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where San Luis sits across the climate record
Three NOAA fields for San Luis's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Cooler than 85%
- Among 6,861 stations, San Luis sits in the cooler third of annual means.
- Annual precipitation
- Drier than 95%
- San Luis's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- 50th percentile swing
- Typical seasonal amplitude versus 6,861 complete station-years.
How San Luis compares across U.S. station-mapped locations
San Luis's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
28 0th percentile score exceeds 0% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). This entry sits in this band.
- 30–40: 280 station-mapped locations (5%). Above this entry.
- 40–50: 1,113 station-mapped locations (18%). Above this entry.
- 50–60: 1,329 station-mapped locations (21%). Above this entry.
- 60–70: 1,236 station-mapped locations (20%). Above this entry.
- 70–80: 650 station-mapped locations (11%). Above this entry.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 37°F (3°C) | 6°F (-14°C) | 22°F (-6°C) | 0.4" | 31.0 | 0.0 |
| February | 41°F (5°C) | 12°F (-11°C) | 27°F (-3°C) | 0.5" | 27.7 | 0.0 |
| March | 52°F (11°C) | 23°F (-5°C) | 37°F (3°C) | 0.3" | 29.6 | 0.0 |
| April | 58°F (15°C) | 27°F (-3°C) | 43°F (6°C) | 0.6" | 23.6 | 0.0 |
| May | 68°F (20°C) | 35°F (1°C) | 51°F (11°C) | 0.7" | 9.7 | 0.1 |
| June | 79°F (26°C) | 42°F (5°C) | 60°F (16°C) | 0.8" | 1.4 | 0.3 |
| July | 82°F (28°C) | 48°F (9°C) | 65°F (18°C) | 1.5" | 0.1 | 1.1 |
| August | 79°F (26°C) | 47°F (9°C) | 63°F (17°C) | 1.3" | 0.0 | 0.1 |
| September | 74°F (23°C) | 39°F (4°C) | 57°F (14°C) | 1.0" | 4.8 | 0.0 |
| October | 63°F (17°C) | 28°F (-2°C) | 46°F (8°C) | 0.9" | 22.9 | 0.0 |
| November | 49°F (10°C) | 18°F (-8°C) | 33°F (1°C) | 0.5" | 28.8 | 0.0 |
| December | 39°F (4°C) | 9°F (-13°C) | 24°F (-5°C) | 0.4" | 31.0 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 82°F around July 9, short of 90°F on every date, while 214 dates carry a normal low at or below freezing, the coldest 6°F near January 16.
The freezing stretch
The normal low stays at or below 32°F into May 6, then returns to freezing around October 6, covering 214 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is August 4, when 27% of years recorded at least a hundredth of an inch. The driest is January 6 at 7%. Summed across the calendar, that is about 47 wet dates a year.
The widest day
June 14 carries the biggest normal gap between afternoon and dawn, 38°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for San Luis.
Where San Luis Stands Nationally
Winters bite deep and often: the normal nightly low dips to freezing or below on around 214 nights a year, placing this among the most frost-prone tenth of ranked stations.
Aridity defines the water calendar: about 9 inches in a normal year lands this among the driest tenth of ranked stations.
San Luis earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall
2.1 days with precipitation
4.0 days with precipitation
3.0 days with precipitation
3.1 days with precipitation
3.4 days with precipitation
3.6 days with precipitation
6.8 days with precipitation
8.5 days with precipitation
4.1 days with precipitation
3.5 days with precipitation
2.4 days with precipitation
2.6 days with precipitation
San Luis runs a summer-peaked wet season
40% of San Luis's yearly precipitation falls in June, July and August alone, against the 25% an evenly spread year would give those three months. The wettest month is July at 1.5", on a 43.4°F seasonal spread. Warm-season convection and, across the Southwest, the North American monsoon produce this shape: rain arrives in short heavy bursts during the hottest part of the year rather than as long cool-season soaking.
- Wettest three months: July, August, September, taking 43% of the annual total between them.
- Driest month: March at 0.3".
- Winter share: 14% falls in December, January and February.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. A summer-peaked label means the June-August share reaches 35%; it describes timing across an average year, not any single season, and says nothing about how heavy an individual storm can be.
San Luis is dry, and what does fall arrives gently
Only about 47 days a year record measurable precipitation here, 13% of the calendar, and they carry 9.0" between them. At roughly 0.19 inches on an average wet day, this is not the damp drizzle of a marine climate; it is an arid record in which precipitation is both uncommon and light when it appears.
The wettest month by count is August at about 9 wet days; the driest is January at about 2.
A low per-event average in a dry record is a statement about typical days only. Arid regions can still take a large share of a year's total from a single convective storm, which a normal cannot show.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, not the extremes within it.
Frost Dates & Growing Season
First Fall Freeze
September 23
50% probability date
Last Spring Freeze
May 31
50% probability date
Growing Season
115 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
7,719
Higher = more heating needed
Cooling Degree Days
75
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside CO closest to San Luis on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (44°F here).
- Blair, WI 44°F · 0.0°F off
- Brockway, MT 44°F · 0.0°F off
- Dassel, MN 44°F · 0.0°F off
- De Smet, SD 44°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (9.0" here), excluding temperature-peer places.
- Wenatchee, WA 9.0" · 0.0" off
- Ellensburg, WA 9.0" · 0.0" off
- Wellington, UT 9.1" · 0.1" off
- Hamer, ID 8.9" · 0.1" off
Scarce-water calendar
Where San Luis's limited precipitation lands
heating led · dry · mid swing
San Luis's energy balance leans toward cold weather: 7,719 annual heating degree days against 75 for cooling. Its 43.4°F seasonal range still makes the monthly rows more useful than the annual average alone.
Only about 115 days are frost-free in a normal year. That short interval is consistent with the cold-season signal, but the measure does not predict the exact first or last freeze in any one year.
July and January mark the typical warm and cold ends of the calendar in San Luis's middle-range seasonal profile. The measured spread is 43.4°F. The annual average is 44°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
San Luis's cold-season load does not imply a wet climate. Annual precipitation is 9.0 inches, which places the station in PlainClimate's dry range. Snowfall is not added to the interpretation because its annual value is missing. The snowfall and rainfall fields should be read separately rather than inferred from temperature.
San Luis wettest normal
July
July concentrates the scarce annual total (9.0 inches).
San Luis driest normal
March
March is typically driest; arid stations are defined by when water is absent, not by a four-season grid.
Questions about San Luis's climate
How dry is San Luis? ▼
How cold does San Luis get in winter? ▼
How much energy does heating and cooling require in San Luis? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from San Luis's primary station: SAN LUIS 1 S (USC00057430). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 0868105). Match rule for San Luis: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for San Luis comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.