Monthly climate in Gillette, Wyoming, United States

Last updated: May 6, 2024

Under the Köppen–Geiger climate classification Gillette features a cold semi-arid climate (BSk).Temperatures typically range between -5 °C (23 °F) and 23 °C (74 °F) through the year, but rarely can drop to -30 °C (-22 °F) or can rise to as high as 41 °C (106 °F).The average annual precipitation amounts to about 471 mm (18.5 inches) and receives 97 rainy days on the 1 mm (0.04 inches) threshold annually.Gillette enjoys an average of 3237 hours of sunshine throughout the year, and daylight varies from 8 hours 54 minutes to 15 hours 26 minutes per day.

Monthly average temperatures in Gillette, Wyoming, United States §

The warmest months in Gillette are June, July and August, with daily mean temperatures ranging from 19 to 23 °C (67 - 74 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from -5 to -1 °C (23 - 30 °F) throughout the day. On average each year, Gillette experiences 75 days above 25 °C (77.0 °F) and 143 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Gillette, Wyoming, United States.Generated using Copernicus Climate Change Service information.Data for period from January 2017 to June 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Maximum 14°C
(58°F)
20°C
(67°F)
25°C
(78°F)
27°C
(81°F)
33°C
(91°F)
39°C
(103°F)
41°C
(106°F)
38°C
(100°F)
38°C
(101°F)
29°C
(84°F)
23°C
(74°F)
21°C
(71°F)
Mean maximum 12°C
(55°F)
15°C
(59°F)
21°C
(71°F)
25°C
(77°F)
30°C
(87°F)
32°C
(89°F)
37°C
(99°F)
36°C
(97°F)
35°C
(95°F)
26°C
(80°F)
19°C
(67°F)
16°C
(61°F)
Average high 3°C
(37°F)
1°C
(34°F)
9°C
(49°F)
12°C
(54°F)
18°C
(64°F)
26°C
(79°F)
30°C
(87°F)
29°C
(84°F)
23°C
(74°F)
13°C
(55°F)
8°C
(47°F)
4°C
(39°F)
Daily mean -3°C
(27°F)
-5°C
(23°F)
3°C
(38°F)
6°C
(42°F)
12°C
(53°F)
19°C
(67°F)
23°C
(74°F)
21°C
(71°F)
16°C
(62°F)
6°C
(44°F)
3°C
(37°F)
-1°C
(30°F)
Average low -8°C
(18°F)
-11°C
(12°F)
-3°C
(27°F)
-1°C
(31°F)
6°C
(42°F)
12°C
(54°F)
16°C
(60°F)
14°C
(57°F)
9°C
(49°F)
1°C
(34°F)
-3°C
(28°F)
-6°C
(22°F)
Mean minimum -21°C
(-6°F)
-25°C
(-13°F)
-13°C
(8°F)
-12°C
(11°F)
-1°C
(30°F)
6°C
(43°F)
9°C
(49°F)
8°C
(46°F)
2°C
(35°F)
-12°C
(11°F)
-13°C
(9°F)
-16°C
(3°F)
Minimum -25°C
(-12°F)
-30°C
(-22°F)
-24°C
(-11°F)
-20°C
(-4°F)
-3°C
(28°F)
2°C
(36°F)
7°C
(45°F)
6°C
(44°F)
-2°C
(30°F)
-21°C
(-6°F)
-19°C
(-2°F)
-23°C
(-9°F)

Compare climate in Gillette with other places

Compare temperature, precipitation, sunshine, UV index in Gillette, Wyoming, United States with other places around the world.

Monthly average precipitation in Gillette, Wyoming, United States §

Gillette usually has the most precipitation in April, May and July, with an average of 11 rainy days and 61 mm (2.4 inches) of precipitation per month.The driest months in Gillette are January, November and December. On average, 21 mm (0.8 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Gillette, Wyoming, United States.Generated using Copernicus Climate Change Service information.Data for period from January 2017 to January 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Average precipitation mm (inches) 19 (0.8) 26 (1.0) 33 (1.3) 61 (2.4) 67 (2.6) 39 (1.6) 56 (2.2) 35 (1.4) 43 (1.7) 47 (1.9) 20 (0.8) 24 (0.9)
Average precipitation days (≥ 1 mm) 5 7 9 11 14 8 9 7 6 9 6 6

Monthly sunshine hours in Gillette, Wyoming, United States §

The sunniest months in Gillette are June, July and August, when the sun shines an average of 12 hours 3 minutes a day.Least sunny months in Gillette: January, February and December receive an average of 6 hours 13 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Gillette, Wyoming, United States.Generated using Copernicus Atmosphere Monitoring Service information.Data for period from January 2017 to January 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Mean monthly sunshine hours 159 205 259 271 298 372 386 350 282 232 217 201
Mean daily daylight hours 9h 17m 10h 28m 11h 57m 13h 29m 14h 47m 15h 26m 15h 5m 13h 55m 12h 27m 10h 55m 9h 35m 8h 54m

Solar UV radiation in Gillette, Wyoming, United States §

Gillette experiences the highest level of ultraviolet (UV) radiation in April, June and July, when the maximum UV index can reach values of 10 - 11, which corresponds to the Very High / Extreme category of sun exposure.January, November and December are in the Low / Moderate exposure category. In these months, the maximum values of the UV index do not exceed 3. For more detailed information, check out our hourly Gillette UV Index data.

Average daily maximum UV levels by month for Gillette, Wyoming, United States.Generated using Copernicus Atmosphere Monitoring Service information.Data for period from January 2022 to January 2023.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
UV Index (month maximum) 3 5 6 10 9 11 11 10 8 5 3 2