Climateby Month

Gillette, WY climate by month

NOAA 1991-2020 normals · 4,554 ft elevation

Gillette has warm summers and cold and snowy winters. Highs peak at 86°F in July and fall to 36°F in December. The wettest month is May (about 13 wet days) and the driest is September (about 6). Normal snowfall is about 56 in a year. By our comfort score the best months are May and June.

Warmest month
86°F
July normal high
Coldest month
16°F
January normal low
Wet days a year
100
17.6 in of precipitation
Snow a year
55.7 in
normal snowfall

How warm is Gillette?

Normal highs range from 36°F in December to 86°F in July.

0°20°40°60°80°100° January: normal high 36°F (2°C), low 16°F (-9°C) 36° 16° February: normal high 38°F (3°C), low 17°F (-8°C) March: normal high 49°F (9°C), low 25°F (-4°C) April: normal high 56°F (13°C), low 32°F (0°C) May: normal high 66°F (19°C), low 41°F (5°C) June: normal high 77°F (25°C), low 50°F (10°C) July: normal high 86°F (30°C), low 57°F (14°C) 86° 57° August: normal high 85°F (29°C), low 56°F (13°C) September: normal high 75°F (24°C), low 46°F (8°C) October: normal high 59°F (15°C), low 34°F (1°C) November: normal high 46°F (8°C), low 24°F (-4°C) December: normal high 36°F (2°C), low 16°F (-9°C) JFMAMJJASOND

Bars run from the normal low to the normal high for each month.

How rainy is Gillette?

May has the most wet days (about 13); the year brings about 18 in of precipitation.

January: 8 wet days February: 8 wet days March: 8 wet days April: 11 wet days May: 13 wet days 13 June: 10 wet days July: 8 wet days August: 6 wet days September: 6 wet days 6 October: 8 wet days November: 6 wet days December: 7 wet days JFMAMJJASOND

Wet day: at least 0.01 in of rain or melted snow, counted from daily records 1991-2020.

How much does it snow?

Normal snowfall is 55.7 in a year, most of it in April.

January: 8.2 in of snow February: 9.0 in of snow March: 8.6 in of snow April: 9.4 in of snow 9.4 May: 1.3 in of snow June: 0.1 in of snow July: 0.0 in of snow 0.0 August: 0.0 in of snow September: 0.5 in of snow October: 4.4 in of snow November: 5.8 in of snow December: 8.4 in of snow JFMAMJJASOND

How humid is Gillette?

Humidity data is not available for this location.

How much daylight?

Daylight ranges from about 8.9 hours in December to 15.5 hours in June.

January: 9.3 hours of daylight February: 10.5 hours of daylight March: 11.9 hours of daylight April: 13.5 hours of daylight May: 14.8 hours of daylight June: 15.5 hours of daylight 15.5 July: 15.1 hours of daylight August: 14.0 hours of daylight September: 12.5 hours of daylight October: 11.0 hours of daylight November: 9.6 hours of daylight December: 8.9 hours of daylight 8.9 JFMAMJJASOND
See all numbers
Monthly climate normals and day counts for Gillette, 1991-2020
MonthHighLowPrecip.Wet daysSnowDaylight
January 36°F16°F 0.6 in8 8.2 in 9.3 h
February 38°F17°F 0.8 in8 9.0 in 10.5 h
March 49°F25°F 1.1 in8 8.6 in 11.9 h
April 56°F32°F 2.1 in11 9.4 in 13.5 h
May 66°F41°F 3.3 in13 1.3 in 14.8 h
June 77°F50°F 2.5 in10 0.1 in 15.5 h
July 86°F57°F 1.7 in8 0.0 in 15.1 h
August 85°F56°F 1.4 in6 0.0 in 14.0 h
September 75°F46°F 1.3 in6 0.5 in 12.5 h
October 59°F34°F 1.6 in8 4.4 in 11.0 h
November 46°F24°F 0.6 in6 5.8 in 9.6 h
December 36°F16°F 0.6 in7 8.4 in 8.9 h

High and low: NOAA 1991-2020 normal daily high and low. Wet days: at least 0.01 in of rain or melted snow. Muggy days: daily mean dew point 65°F or higher.

Best months to visit Gillette

By our comfort score, the best months are May and June.

Comfort score by month (0-100) and its parts, in days per month
MonthScoreComfortableNotable rainHot or cold
Jan 320219
Feb 350216
Mar 49439
Apr 60854
May 711471
Jun 741663
Jul 576412
Aug 576310
Sep 661233
Oct 591143
Nov 413211
Dec 300220

Score = 40 × share of comfortable days + 25 × share of days without notable rain + 20 × share of days neither hot (90°F+) nor cold (high 40°F or below) + 15 × daylight. Comfortable days here are judged by temperature only (no humidity station nearby). How the score works.

Frost dates in Gillette

The last spring frost typically comes around May 22, and the first fall frost around Sep 25, leaving 125 frost-free days in a typical year.

Frost and freeze dates for Gillette
Typical date1 year in 10
Last spring frost (32°F)May 22after Jun 4
First fall frost (32°F)Sep 25before Sep 9
Last hard freeze (28°F)May 9after May 22
First hard freeze (28°F)Oct 4before Sep 20
Frost-free season125 daysunder 106 days

"Typical" is the date with a 50% chance of a later spring frost (or earlier fall frost). Planting after the "1 year in 10" spring date gives a 90% chance of no further frost. The Old Farmer's Almanac publishes 30% dates, which fall between our typical and 1-in-10 dates.

Station: Gillette Campbell Airport (USW00094023), NOAA 1991-2020 freeze probabilities. Frost dates for every city in Wyoming.

Hottest and coldest readings, 1991-2020

The highest reading was 107°F (June 24, 2012); the lowest was -33°F (February 2, 1996).

From the temperature station's daily records with NOAA quality flags removed. Not an all-time record.

Near Gillette

Similar climates elsewhere

Where the numbers come from

  • Temperature, rain, snowfall and snow depth: Gillette 4SE (USC00483855), 3.1 mi ESE of the city center, 4,640 ft (86 ft higher than the city). NOAA normals and daily records, 1991-2020.
  • Frost dates and humidity and wind by hour: Gillette Campbell Airport (USW00094023), 3.9 mi NNW of the city center, 4,354 ft (200 ft lower than the city). NOAA normals and daily records, 1991-2020.
  • Not available for this location: cloud cover and daily humidity and wind (no station close enough or similar enough in elevation).

Distances from the city center (USGS). Methodology · Report an error