Fort Lewis, CO Climate: Temperature by Month
Average temperature and precipitation from NOAA NCEI 1991–2020 normals →, with a derived climate comfort score
30-year climate normals (1991-2020) from Fort Lewis's primary NOAA station, FT LEWIS.
The climate verdict for Fort Lewis
Fort Lewis, Colorado has a mixed annual climate rather than one dominant extreme. Its NOAA normal shows an annual average of 44°F. July is the warmest month at 66°F and January the coldest at 24°F.
- 44°F
- average temperature, NOAA 1991-2020 normal
- 118 days
- growing season, frost-free days
Fort Lewis: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00053016 · Fort Lewis, CO 44°F mean
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-UNK · SWING-MID · COMF-UNK · LOAD-HEAT · STN-1 · BOOK-PART
- TEMP-COOL 44°F
- RANK-COOL #1,098
- PHOTO-FINISH ≈ Longmire Rainie…
- PRCP-UNK Rain n/a
- SWING-MID 42°F
- COMF-UNK Comfort n/a
- LOAD-HEAT 7,625 HDD
- STN-1 USC00053016
- BOOK-PART 4/6 fields
Nearest mean-temperature peer: Longmire Rainier Nps, WA (+ 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.
- Hot Great Sand Dune…, CO 45°F
- Fort Lewis (this station) 44°F
- Near Longmire Rainie…, WA 44°F
- Near Bryce Canyon Na…, UT 44°F
- Near Double Four Rch, WY 44°F
Climate Living Index · Fort Lewis
Fort Lewis: 14/100 · grade F
Fort Lewis publishes 3 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 3 missing weights rescale to 100.
PlainClimate-derived for Fort Lewis, not an official NOAA rating. Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Annual temperature balance | 44.3°F · 23.2° from 67.5°F | 17/100 · F |
| Normal heat + freeze calendar | 198 calendar days | 15/100 · F |
| Frost-free season | 118 days/year | 6/100 · F |
Fort Lewis · 2026-08-04 · NOAA NCEI Climate Normals · method .
National standing · heating-led station
Where Fort Lewis sits across the climate record
Available NOAA 1991–2020 fields for Fort Lewis are ranked only against stations that publish the same field, missing metrics stay blank rather than estimated.
- Annual temperature
- Cooler than 84%
- Among 6,861 stations, Fort Lewis sits in the cooler third of annual means.
- Seasonal temperature swing
- 43rd percentile swing
- Typical seasonal amplitude versus 6,861 complete station-years.
Fort Lewis's measured station temperature trend
MethodologyAcross 54 complete annual observations from 1921 to 2023, FT LEWIS warmed at a fitted rate of 0.17°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Fort Lewis primary station fitted change +0.17 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 36°F (2°C) | 12°F (-11°C) | 24°F (-5°C) | N/A | 30.9 | 0.0 |
| February | 40°F (4°C) | 17°F (-9°C) | 28°F (-2°C) | N/A | 27.7 | 0.0 |
| March | 48°F (9°C) | 23°F (-5°C) | 35°F (2°C) | N/A | 28.9 | 0.0 |
| April | 56°F (13°C) | 29°F (-2°C) | 42°F (6°C) | N/A | 23.6 | 0.0 |
| May | 66°F (19°C) | 36°F (2°C) | 51°F (10°C) | N/A | 12.5 | 0.0 |
| June | 76°F (25°C) | 43°F (6°C) | 60°F (15°C) | N/A | 2.4 | 0.4 |
| July | 80°F (27°C) | 51°F (11°C) | 66°F (19°C) | N/A | 0.1 | 1.5 |
| August | 78°F (26°C) | 50°F (10°C) | 64°F (18°C) | N/A | 0.1 | 0.2 |
| September | 71°F (22°C) | 43°F (6°C) | 57°F (14°C) | N/A | 2.3 | 0.0 |
| October | 60°F (15°C) | 32°F (0°C) | 46°F (8°C) | N/A | 17.2 | 0.0 |
| November | 46°F (8°C) | 22°F (-5°C) | 34°F (1°C) | N/A | 28.1 | 0.0 |
| December | 36°F (2°C) | 14°F (-10°C) | 25°F (-4°C) | N/A | 30.7 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 81°F around July 11, short of 90°F on every date, while 198 dates carry a normal low at or below freezing, the coldest 11°F near January 1.
The freezing stretch
The normal low stays at or below 32°F into April 30, then returns to freezing around October 16, covering 198 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.
The widest day
June 15 carries the biggest normal gap between afternoon and dawn, 34°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Fort Lewis.
Where Fort Lewis Stands Nationally
Winters bite deep and often: the normal nightly low dips to freezing or below on around 198 nights a year, placing this among the most frost-prone tenth of ranked stations.
Daily temperature swings run wider than most of the country, peaking near 34°F between the normal high and low.
Fort Lewis earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.
Monthly Precipitation
Average monthly rainfall
Frost Dates & Growing Season
First Fall Freeze
September 27
50% probability date
Last Spring Freeze
June 1
50% probability date
Growing Season
118 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
7,625
Higher = more heating needed
Cooling Degree Days
110
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside CO closest to Fort Lewis 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).
- Gettysburg, SD 44°F · 0.0°F off
- Harrold, SD 44°F · 0.0°F off
- Jim Falls, WI 44°F · 0.0°F off
- Kewaunee, WI 44°F · 0.0°F off
Data-derived climate profile
How Fort Lewis's climate pattern fits together
heating led · mid swing
Fort Lewis's energy balance leans toward cold weather: 7,625 annual heating degree days against 110 for cooling. Its 41.8°F seasonal range still makes the monthly rows more useful than the annual average alone.
Only about 118 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 Fort Lewis's middle-range seasonal profile. The measured spread is 41.8°F. The annual average is 44°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
A moisture-range label is withheld because Fort Lewis's annual precipitation total is unavailable. Monthly source values remain visible where NOAA provides them, and no annual amount is reconstructed from incomplete data.
These labels group NOAA 1991-2020 normals from Fort Lewis's primary station, so the winter figures are a thirty-year average and not a floor: a single hard season can run well below them. Treat each band as a descriptive range for Fort Lewis, not an official NOAA class or a year-ahead forecast.
Questions about Fort Lewis's climate
How cold does Fort Lewis get in winter? ▼
How much energy does heating and cooling require in Fort Lewis? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Fort Lewis's primary station: FT LEWIS (USC00053016). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The conservative exact name-and-state crosswalk finds no Census place match, so PlainClimate treats this as a station-mapped location and does not claim it is a municipality. No exact Gazetteer row for Fort Lewis; facility counts that depend on place identity are therefore an upper bound, not a municipal census.
On this page every temperature, precipitation, and derived score for Fort Lewis 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.