Fort Lewis, Colorado climate: Climate normals at a NOAA weather station
Fort Lewis's normal year runs from 12°F January nights to 80°F July afternoons. (NOAA 1991-2020 normals)
In metric: a yearly mean of 6.8°C, January lows of −11°C, July highs of 27°C.
- NOAA stationFort Lewis
- Station IDUSC00053016
- Location37.23°N 108.05°W
- Elevation7,614 ft (2,321 m)
On October 23, the normal high in Fort Lewis is 57°F and the normal low 29°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Fort Lewis.
- Jan 36° 12°
- Feb 40° 17°
- Mar 48° 23°
- Apr 56° 29°
- May 66° 36°
- Jun 76° 43°
- Jul 80° 51°
- Aug 78° 50°
- Sep 71° 43°
- Oct 60° 32°
- Nov 46° 22°
- Dec 36° 14°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Fort Lewis each month?
July is the warmest month, with normal highs of 80°F; January the coldest, with normal lows of 12°F.
| Month | High | Low | Mean | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|
| January | 36°F | 12°F | 23.9°F | – | <1 | 31 | 9 h 50 min |
| February | 40°F | 17°F | 28.0°F | – | <1 | 28 | 10 h 50 min |
| March | 48°F | 23°F | 35.4°F | – | <1 | 29 | 11 h 50 min |
| April | 56°F | 29°F | 42.4°F | – | <1 | 24 | 13 h 10 min |
| May | 66°F | 36°F | 50.6°F | – | <1 | 13 | 14 h 10 min |
| June | 76°F | 43°F | 59.7°F | – | <1 | 2 | 14 h 40 min |
| July | 80°F | 51°F | 65.7°F | – | 2 | <1 | 14 h 30 min |
| August | 78°F | 50°F | 64.1°F | – | <1 | <1 | 13 h 40 min |
| September | 71°F | 43°F | 57.0°F | – | <1 | 2 | 12 h 30 min |
| October | 60°F | 32°F | 45.8°F | – | <1 | 17 | 11 h 20 min |
| November | 46°F | 22°F | 34.3°F | – | <1 | 28 | 10 h 10 min |
| December | 36°F | 14°F | 25.0°F | – | <1 | 31 | 9 h 40 min |
| Year (annual) | 58°F | 31°F | 44.3°F | – | 2 | 205 |
The same normals in °C and millimetres
| Month | High | Low | Mean |
|---|---|---|---|
| January | 2°C | −11°C | −4.5°C |
| February | 4°C | −9°C | −2.2°C |
| March | 9°C | −5°C | 1.9°C |
| April | 13°C | −2°C | 5.8°C |
| May | 19°C | 2°C | 10.3°C |
| June | 25°C | 6°C | 15.4°C |
| July | 27°C | 11°C | 18.7°C |
| August | 26°C | 10°C | 17.8°C |
| September | 22°C | 6°C | 13.9°C |
| October | 15°C | 0°C | 7.7°C |
| November | 8°C | −5°C | 1.3°C |
| December | 2°C | −10°C | −3.9°C |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Durango station (12 miles away), gets 64 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00053016; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
Which months are mildest at Fort Lewis?
Normal highs sit between 65°F and 85°F in May, June, July, August and September.
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00053016.
When is the last frost at Fort Lewis?
In Fort Lewis, the last spring frost (32°F) comes after June 1 in half of years and after June 19 in one year in ten; the first autumn frost comes before September 27 in half of years and before September 13 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- June 11 year in 10 after June 19; 9 in 10 after May 16
- First autumn frost, half of years before
- September 271 year in 10 before September 13; 9 in 10 before October 8
NOAA puts the median frost-free season at 116 days, and the season without a hard freeze (28°F) at 139 days.
A hard freeze (28°F) comes after May 17 in half of springs and before October 6 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Fort Lewis in zone 6a in ZIP code 81326, the nearest ZIP area.
Frost dates for every NOAA station in Colorado · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00053016; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get at Fort Lewis?
In a normal year in Fort Lewis, 2 days a year reach 90°F and 205 nights fall to 32°F or colder.
- Days at 90°F or more
- 2a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 205a normal year
- Days that stay below freezing
- 24high of 32°F or less
The highest temperature in this station's record (since 1917) is 102°F, on July 4, 1973; the lowest is −35°F, on January 12, 1963.
The wettest calendar year on that record is 1965, with 25.53 in; the snowiest season is 1992–93, with 167.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00053016; records: ACIS (NOAA Regional Climate Centers), station USC00053016. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Fort Lewis?
Over a year 83% of the sunlight that would reach the ground under clear skies gets through the clouds at Fort Lewis, 5.3 kWh per square metre a day. June is the sunniest month (91%) and December the cloudiest (75%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 78% | 2.8 |
| February | 76% | 3.7 |
| March | 80% | 5.1 |
| April | 81% | 6.4 |
| May | 84% | 7.5 |
| June | 91% | 8.3 |
| July | 85% | 7.3 |
| August | 84% | 6.5 |
| September | 86% | 5.7 |
| October | 85% | 4.4 |
| November | 83% | 3.2 |
| December | 75% | 2.4 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How many heating and cooling degree days does Fort Lewis record?
A normal year at Fort Lewis brings 7,625 heating degree days, 42% more than the median U.S. place (5,373), and 110 cooling degree days, 88% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,577 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,273 | 0 |
| February | 1,036 | 0 |
| March | 918 | 0 |
| April | 678 | 0 |
| May | 445 | 1 |
| June | 173 | 14 |
| July | 36 | 58 |
| August | 64 | 35 |
| September | 243 | 3 |
| October | 597 | 0 |
| November | 921 | 0 |
| December | 1,242 | 0 |
| Year (annual) | 7,625 | 110 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00053016. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Have recent years at Fort Lewis been warmer than normal?
2023 averaged 44.2°F, 0.1°F below the 1991-2020 normal of 44.3°F.
| Year | Mean | Against normal |
|---|---|---|
| 2023 | 44.2°F | −0.1°F |
Over 54 complete years from 1921 to 2023, the station's annual mean temperature rose at a fitted 3.0°F per century (+0.17°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00053016; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Fort Lewis's climate compare?
Fort Lewis is warmer than 39 of the 125 places with their own NOAA record in Colorado. Across the 7,247 U.S. stations with normals, its annual mean of 44.3°F is warmer than 17%.
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers.
Which places near Fort Lewis share this climate record?
Marvel has no NOAA station with 1991-2020 normals of its own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Marvel, CO91 people · 9 mi SW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Fort Lewis's climate
What is the coldest month at Fort Lewis?
January, with a normal high of 36°F and a normal low of 12°F. The warmest is July (80°F by day, 51°F at night).
Does it snow at Fort Lewis?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Durango station (12 miles away), records 64 inches of snow in a normal year.
What plant hardiness zone is Fort Lewis in?
The USDA's 2023 map puts Fort Lewis in zone 6a in ZIP code 81326, the nearest ZIP area.
How late can frost come at Fort Lewis?
In half of years the last 32°F night comes after June 1; in one year in ten it comes after June 19. Waiting until June 19 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Colorado climateThe statewide normals and every place in the state
- Mancos, CO16 miles from this station, 46.3°F a year
- Durango, CO17 miles from this station, 46.4°F a year
- Lemon Dam, CO24 miles from this station, 42.9°F a year
- Mesa Verde National Park, CO24 miles from this station, 49.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made