Gillette, Wyoming climate: Normal weather by month, frost dates and records
Gillette's normal year runs from 14°F January nights to 87°F July afternoons, with 13.6 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 7.7°C, January lows of −10°C, July highs of 31°C, 345 mm of precipitation a year.
- NOAA stationGillette Campbell Airport
- Station IDUSW00094023
- Location44.34°N 105.54°W
- Elevation4,354 ft (1,327 m)
- Population33,846
On October 23, the normal high in Gillette is 55°F and the normal low 30°F, and the chance of measurable rain or snow is 24%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Gillette.
- Jan 36° 14°
- Feb 37° 15°
- Mar 48° 23°
- Apr 55° 30°
- May 65° 39°
- Jun 77° 48°
- Jul 87° 56°
- Aug 86° 54°
- Sep 75° 44°
- Oct 59° 32°
- Nov 46° 22°
- Dec 36° 15°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Gillette each month?
July is the warmest month, with normal highs of 87°F; January the coldest, with normal lows of 14°F. The most precipitation falls in May (2.63 in), the least in January (0.33 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 36°F | 14°F | 25.2°F | 0.33 | 7 | <1 | 30 | 9 h 10 min |
| February | 37°F | 15°F | 26.1°F | 0.43 | 9 | <1 | 27 | 10 h 30 min |
| March | 48°F | 23°F | 35.6°F | 0.83 | 8 | <1 | 26 | 11 h 50 min |
| April | 55°F | 30°F | 42.5°F | 1.60 | 11 | <1 | 18 | 13 h 20 min |
| May | 65°F | 39°F | 52.1°F | 2.63 | 12 | <1 | 7 | 14 h 40 min |
| June | 77°F | 48°F | 62.5°F | 2.03 | 10 | 4 | <1 | 15 h 30 min |
| July | 87°F | 56°F | 71.3°F | 1.52 | 8 | 16 | <1 | 15 h 10 min |
| August | 86°F | 54°F | 69.8°F | 0.97 | 7 | 12 | <1 | 14 h 10 min |
| September | 75°F | 44°F | 59.4°F | 0.98 | 7 | 4 | 2 | 12 h 40 min |
| October | 59°F | 32°F | 45.5°F | 1.38 | 9 | <1 | 15 | 11 h |
| November | 46°F | 22°F | 33.6°F | 0.52 | 6 | <1 | 25 | 9 h 40 min |
| December | 36°F | 15°F | 25.4°F | 0.36 | 7 | <1 | 30 | 8 h 50 min |
| Year (annual) | 59°F | 33°F | 45.8°F | 13.58 | 100 | 35 | 179 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 2°C | −10°C | −3.8°C | 8 mm |
| February | 3°C | −9°C | −3.3°C | 11 mm |
| March | 9°C | −5°C | 2.0°C | 21 mm |
| April | 13°C | −1°C | 5.8°C | 41 mm |
| May | 18°C | 4°C | 11.2°C | 67 mm |
| June | 25°C | 9°C | 16.9°C | 52 mm |
| July | 31°C | 13°C | 21.8°C | 39 mm |
| August | 30°C | 12°C | 21.0°C | 25 mm |
| September | 24°C | 7°C | 15.2°C | 25 mm |
| October | 15°C | 0°C | 7.5°C | 35 mm |
| November | 8°C | −6°C | 0.9°C | 13 mm |
| December | 2°C | −10°C | −3.7°C | 9 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. Gillette's own co-op station Gillette (4 mi SE) does: 56 inches of snow in a normal year (see the other stations below).
Source: NOAA NCEI 1991-2020 monthly normals, station USW00094023; 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.
When is the best weather to visit Gillette?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September has the fewest days with rain (7).
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 USW00094023.
When is the last frost in Gillette?
In Gillette, the last spring frost (32°F) comes after May 22 in half of years and after June 4 in one year in ten; the first autumn frost comes before September 25 in half of years and before September 9 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
- May 221 year in 10 after June 4; 9 in 10 after May 8
- First autumn frost, half of years before
- September 251 year in 10 before September 9; 9 in 10 before October 8
NOAA puts the median frost-free season at 125 days, and the season without a hard freeze (28°F) at 148 days.
A hard freeze (28°F) comes after May 9 in half of springs and before October 4 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Gillette in zone 4b in ZIP code 82727, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Gillette's NOAA station is in zone 5a: the coldest night of a typical year reaches −19°F (19 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Wyoming · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00094023; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. 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 in Gillette?
In a normal year in Gillette, 35 days a year reach 90°F (3 of them 100°F or more), 179 nights fall to 32°F or colder and 100 days bring measurable precipitation.
- Days at 90°F or more
- 35a normal year
- Days at 100°F or more
- 3a normal year
- Nights at 32°F or colder
- 179a normal year
- Days that stay below freezing
- 41high of 32°F or less
- Days with 0.01 inch of precipitation
- 100a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USW00094023.
How humid and windy is Gillette, and how clear are its skies?
The summer (June-August) dew point averages 46°F. The muggiest month is July, with an average dew point of 48°F; the driest air comes in December (13°F). November is the windiest month (11.4 mph on average), and July has the most clear or nearly clear hours (82%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 15°F | 63% | 51% | 11.3 mph | 65% | 20% |
| February | 17°F | 62% | 46% | 10.6 mph | 64% | 22% |
| March | 25°F | 58% | 39% | 11.3 mph | 58% | 26% |
| April | 33°F | 60% | 40% | 11.2 mph | 60% | 24% |
| May | 44°F | 61% | 40% | 9.9 mph | 59% | 18% |
| June | 48°F | 51% | 29% | 9.1 mph | 79% | 5% |
| July | 48°F | 46% | 25% | 8.8 mph | 82% | 5% |
| August | 42°F | 42% | 23% | 9.3 mph | 81% | 7% |
| September | 34°F | 51% | 30% | 9.8 mph | 74% | 12% |
| October | 24°F | 54% | 36% | 10.5 mph | 67% | 21% |
| November | 17°F | 61% | 49% | 11.4 mph | 66% | 20% |
| December | 13°F | 63% | 54% | 11.0 mph | 67% | 21% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00094023. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Gillette?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Gillette, 4.3 kWh per square metre a day. July is the sunniest month (88%) and December the cloudiest (68%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 71% | 1.8 |
| February | 70% | 2.7 |
| March | 72% | 3.9 |
| April | 71% | 5.0 |
| May | 73% | 6.0 |
| June | 82% | 7.1 |
| July | 88% | 7.2 |
| August | 87% | 6.2 |
| September | 82% | 4.8 |
| October | 75% | 3.1 |
| November | 74% | 2.1 |
| December | 68% | 1.5 |
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 much heating and cooling does Gillette need?
A normal year in Gillette brings 7,497 heating degree days, 40% more than the median U.S. place (5,373), and 519 cooling degree days, 43% 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 2,232 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,234 | 0 |
| February | 1,089 | 0 |
| March | 910 | 0 |
| April | 674 | 0 |
| May | 407 | 7 |
| June | 138 | 62 |
| July | 18 | 215 |
| August | 37 | 184 |
| September | 215 | 48 |
| October | 609 | 3 |
| November | 941 | 0 |
| December | 1,226 | 0 |
| Year (annual) | 7,497 | 519 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00094023. 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.
Has Gillette been warmer than normal lately?
2023 averaged 46.8°F, 1.0°F above the 1991-2020 normal of 45.8°F. 2 of the 3 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 47.5°F | +1.7°F | 8.62 |
| 2022 | 45.5°F | −0.3°F | 14.84 |
| 2023 | 46.8°F | +1.0°F | 17.39 |
Over 30 complete years from 1985 to 2023, the station's annual mean temperature rose at a fitted 2.3°F per century (+0.13°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00094023; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Gillette's climate compare?
Gillette is warmer than 51 of the other 70 places with their own NOAA record in Wyoming, and wetter than 39. Across the 7,247 U.S. stations with normals, its annual mean of 45.8°F is warmer than 23%.
In the Köppen classification computed from these normals, Gillette is BSk: cold semi-arid steppe. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Gillette share this climate record?
Sleepy Hollow 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.
- Sleepy Hollow, WY1,812 people · 9 mi SE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Gillette's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Gillette. This page uses Gillette Campbell Airport; the other differs by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Gillette (4 mi SE) USC00483855 | 7 mi SE | 4,640 ft | 46.8°F | 16°F | 86°F | 17.6 | 56 | May 15 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Gillette's climate
What is the coldest month in Gillette?
January, with a normal high of 36°F and a normal low of 14°F. The warmest is July (87°F by day, 56°F at night).
Does it snow in Gillette?
Yes. NOAA publishes no 1991-2020 snowfall normal for Gillette's NOAA station; Gillette's own co-op station Gillette (4 mi SE) records 56 inches of snow in a normal year.
What is the rainiest month in Gillette?
May, with 2.63 in of precipitation in a normal year; the driest is January with 0.33 in.
What plant hardiness zone is Gillette in?
The USDA's 2023 map puts Gillette in zone 4b in ZIP code 82727, the nearest ZIP area. By the same method at Gillette's NOAA station, the coldest night of a typical year reaches −19°F (19 years, 1991-2020): zone 5a.
How late can frost come in Gillette?
In half of years the last 32°F night comes after May 22; in one year in ten it comes after June 4. Waiting until June 4 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Gillette in OctoberThis month day by day, its records and recent years
- Wyoming climateThe statewide normals and every place in the state
- Echeta (2 mi NW), WY21 miles from this station, 45.8°F a year
- Weston (1 mi E), WY24 miles from this station, 45.5°F a year
- Dillinger, WY27 miles from this station, 45.0°F a year
- Moorcroft, WY32 miles from this station, 44.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made