Casper weather in December

In December, Casper sees average daytime highs of 30°F and overnight lows near 13°F, with 0.9 in of precipitation across 5.6 wet days and about 8.9 hours of daylight. It is the 11th-warmest and 9th-wettest month of the year here.

Highs ease over the month, from about 33°F in the first days to 28°F by the end. The sky is clear or mostly clear about 42% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 06 min at the start of December to 8 h 54 min by month's end. Set against the rest of the year, December is Casper's 8th-clearest and 1st-windiest month. For the whole year in context, see Casper's year-round climate.

Daytime high: 30°; 11th warmest
Overnight low: 13°; 2nd coldest
Precipitation: 0.9 in; 5.6 wet days
Daylight: 8 h 54 min; 7:36 AM – 4:27 PM
Cloud cover: 50%; 8th clearest
Wind: 9 mph; 1st windiest
Solar energy: 2.16 kWh/m²
Travel score: 0.0; out of 10

Casper is city in and county seat of Natrona County, Wyoming, United States.

Density: 868/km²; people per km²

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

← November Casper year-round climate January →Best places to visit in December

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 33°F in the first days to 28°F by the end.

A typical December day in Casper reaches about 30°F in the afternoon and slips back to 13°F overnight — a 17°F spread between the day's warmth and the night's chill. On most days the high lands between 17°F and 42°F. Set against its neighbours, December runs about 11°F cooler than November and on par with January.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Avg high (°F)	34	34	33	33	33	32	32	32	31	31	31	31	30	30	30	30	29	29	29	29	29	28	28	28	28	28	28	28	28	28	28
Avg low (°F)	17	17	16	16	15	15	15	15	14	14	14	13	13	13	13	12	12	12	12	11	11	11	11	11	11	11	11	11	11	11	11

	Avg high (°F)	Avg low (°F)
1	34	17
2	34	17
3	33	16
4	33	16
5	33	15
6	32	15
7	32	15
8	32	15
9	31	14
10	31	14
11	31	14
12	31	13
13	30	13
14	30	13
15	30	13
16	30	12
17	29	12
18	29	12
19	29	12
20	29	11
21	29	11
22	28	11
23	28	11
24	28	11
25	28	11
26	28	11
27	28	11
28	28	11
29	28	11
30	28	11
31	28	11

How December really feels in Casper

Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 31 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F

heat index over the day's high

Days feeling ≤ 32°F

31 feel bitter (≤ 14°F)

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Casper weather by month

How December compares with the rest of the year at a glance. December is the 11th-warmest and 9th-wettest month here — the current month is highlighted below.

Month	High / Low (°F)	Rainfall (inches)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	29° / 12°	0.8	5.6	5.7	9.2	0.0
Feb	32° / 13°	1.0	5.9	5.8	10.2	0.0
Mar	42° / 22°	1.5	7.1	6	11.6	0.5
Apr	50° / 29°	2.3	10.8	7	13.1	2.3
May	62° / 39°	2.7	11.1	2.3	14.4	5.0
Jun	75° / 49°	1.4	6.3	0.1	15.1	7.5
Jul	84° / 56°	0.7	4.5	0	14.8	6.5
Aug	82° / 55°	0.6	4.1	0	13.8	7.3
Sep	71° / 46°	1.1	5.6	0.7	12.3	7.5
Oct	55° / 33°	1.8	7	4.1	10.8	4.0
Nov	41° / 22°	1.1	5.7	5.5	9.5	0.4
Dec	30° / 13°	0.9	5.6	6.1	8.9	0.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 42% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 18% of December, with mostly cloudy or overcast conditions the remaining 40%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Clearer (%)	61	61	59	59	59	59	59	59	59	59	59	59	59	60	60	60	60	60	60	60	61	61	61	61	61	61	60	60	60	59	59
Cloudier (%)	39	39	41	41	41	41	41	41	41	41	41	41	41	40	40	40	40	40	40	40	39	39	39	39	39	39	40	40	40	41	41

	Clearer (%)	Cloudier (%)
1	61	39
2	61	39
3	59	41
4	59	41
5	59	41
6	59	41
7	59	41
8	59	41
9	59	41
10	59	41
11	59	41
12	59	41
13	59	41
14	60	40
15	60	40
16	60	40
17	60	40
18	60	40
19	60	40
20	60	40
21	61	39
22	61	39
23	61	39
24	61	39
25	61	39
26	61	39
27	60	40
28	60	40
29	60	40
30	59	41
31	59	41

Chance of precipitation in December

Any precipitationSnow

Casper gets around 0.9 in of rain and snow over 5.6 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 18% and peaks near 20% on the wettest days, and about 6 days bring snow.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Rain chance (%)	19	19	18	18	17	17	17	17	17	17	17	17	17	18	18	18	19	19	19	20	20	20	20	20	20	19	19	19	19	18	18
Snow chance (%)	20	20	19	19	19	19	18	18	18	18	18	19	19	19	20	20	21	21	21	21	21	21	21	21	21	21	20	20	19	19	18

	Rain chance (%)	Snow chance (%)
1	19	20
2	19	20
3	18	19
4	18	19
5	17	19
6	17	19
7	17	18
8	17	18
9	17	18
10	17	18
11	17	18
12	17	19
13	17	19
14	18	19
15	18	20
16	18	20
17	19	21
18	19	21
19	19	21
20	20	21
21	20	21
22	20	21
23	20	21
24	20	21
25	20	21
26	19	21
27	19	20
28	19	20
29	19	19
30	18	19
31	18	18

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Dry (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

Wind in December

Winds average 9 mph in December, the windiest month of the year.

Across December, daily wind ranges from about 9 mph on the calmest days to 9 mph at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Wind speed (mph)	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9
Feels	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze

	Wind speed (mph)	Feels
1	9	light breeze
2	9	light breeze
3	9	light breeze
4	9	light breeze
5	9	light breeze
6	9	light breeze
7	9	light breeze
8	9	light breeze
9	9	light breeze
10	9	light breeze
11	9	light breeze
12	9	light breeze
13	9	light breeze
14	9	light breeze
15	9	light breeze
16	9	light breeze
17	9	light breeze
18	9	light breeze
19	9	light breeze
20	9	light breeze
21	9	light breeze
22	9	light breeze
23	9	light breeze
24	9	light breeze
25	9	light breeze
26	9	light breeze
27	9	light breeze
28	9	light breeze
29	9	light breeze
30	9	light breeze
31	9	light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 06 min at the start of December to 8 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 7:23 AM to 7:42 AM, and sunset from 4:27 PM to 4:35 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Daylight (h)	9.1	9.1	9.0	9.0	9.0	9.0	9.0	8.9	8.9	8.9	8.9	8.9	8.9	8.9	8.9	8.9	8.8	8.8	8.8	8.8	8.8	8.8	8.8	8.8	8.8	8.8	8.8	8.9	8.9	8.9	8.9
Sunrise (AM)	7:23	7:24	7:25	7:26	7:27	7:28	7:29	7:30	7:30	7:31	7:32	7:33	7:34	7:34	7:35	7:36	7:36	7:37	7:38	7:38	7:39	7:39	7:40	7:40	7:40	7:41	7:41	7:41	7:42	7:42	7:42
Sunset (PM)	4:27	4:27	4:27	4:27	4:26	4:26	4:26	4:26	4:26	4:26	4:26	4:26	4:26	4:27	4:27	4:27	4:27	4:28	4:28	4:28	4:29	4:29	4:30	4:30	4:31	4:31	4:32	4:33	4:33	4:34	4:35

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	9.1	7:23	4:27
2	9.1	7:24	4:27
3	9.0	7:25	4:27
4	9.0	7:26	4:27
5	9.0	7:27	4:26
6	9.0	7:28	4:26
7	9.0	7:29	4:26
8	8.9	7:30	4:26
9	8.9	7:30	4:26
10	8.9	7:31	4:26
11	8.9	7:32	4:26
12	8.9	7:33	4:26
13	8.9	7:34	4:26
14	8.9	7:34	4:27
15	8.9	7:35	4:27
16	8.9	7:36	4:27
17	8.8	7:36	4:27
18	8.8	7:37	4:28
19	8.8	7:38	4:28
20	8.8	7:38	4:28
21	8.8	7:39	4:29
22	8.8	7:39	4:29
23	8.8	7:40	4:30
24	8.8	7:40	4:30
25	8.8	7:40	4:31
26	8.8	7:41	4:31
27	8.8	7:41	4:32
28	8.9	7:41	4:33
29	8.9	7:42	4:33
30	8.9	7:42	4:34
31	8.9	7:42	4:35

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.16 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.16 kWh/m² to a high of 7.76 kWh/m² in June across the year — December's 2.16 kWh/m² sits near the bottom.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Solar energy (kWh/m²)	2.3	2.3	2.2	2.2	2.2	2.2	2.2	2.2	2.2	2.2	2.1	2.1	2.1	2.1	2.1	2.1	2.1	2.1	2.1	2.1	2.1	2.1	2.1	2.2	2.2	2.2	2.2	2.2	2.2	2.2	2.2
Level	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate

	Solar energy (kWh/m²)	Level
1	2.3	Moderate
2	2.3	Moderate
3	2.2	Moderate
4	2.2	Moderate
5	2.2	Moderate
6	2.2	Moderate
7	2.2	Moderate
8	2.2	Moderate
9	2.2	Moderate
10	2.2	Moderate
11	2.1	Moderate
12	2.1	Moderate
13	2.1	Moderate
14	2.1	Moderate
15	2.1	Moderate
16	2.1	Moderate
17	2.1	Moderate
18	2.1	Moderate
19	2.1	Moderate
20	2.1	Moderate
21	2.1	Moderate
22	2.1	Moderate
23	2.1	Moderate
24	2.2	Moderate
25	2.2	Moderate
26	2.2	Moderate
27	2.2	Moderate
28	2.2	Moderate
29	2.2	Moderate
30	2.2	Moderate
31	2.2	Moderate

Planning a trip in December

Is December a good time to visit Casper?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

0.0

Sightseeing

10th-best month of the year

0.0

Beach & pool

8th-best month of the year

December is a weaker month for outdoor sightseeing in Casper.

What to pack for Casper in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Casper sees daytime highs around 30°F and nights near 13°F. Pack a warm layer and a heavy coat. About 6 days see rain.

a warm layera heavy coat

UV index in Casper in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Casper peaks around July 11 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	2	3	5	6	8	10	10	8	7	4	3	2
Level	Low	Moderate	High	High	Very high	Very high	Very high	Very high	High	Moderate	Moderate	Low

	UV index (midday)	Level
Jan	2	Low
Feb	3	Moderate
Mar	5	High
Apr	6	High
May	8	Very high
Jun	10	Very high
Jul	10	Very high
Aug	8	Very high
Sep	7	High
Oct	4	Moderate
Nov	3	Moderate
Dec	2	Low

Location & terrain

Where is Casper?

Casper sits at 42.9°N, 106.3°W, 5,118 ft above sea level, in United States. The nearest listed city is Gillette, 106 mi away.

Topography around Casper

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Casper.

Within 2 miles, the terrain around Casper has only modest variations in elevation — a maximum elevation change of 282 ft around an average of 5,180 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,173 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,770 ft.

The land around Casper is covered by grassland (49%) and artificial surfaces (32%) within 2 miles, grassland (81%) within 10 miles, and grassland (91%) within 50 miles.

2 miles

282 ft

grassland 49%

10 miles

3,173 ft

grassland 81%

50 miles

4,770 ft

grassland 91%

treesshrubsgrasslandcroplandartificial surfacesbare terrainwater

← November Casper year-round climate January →Best places to visit in December

December weather nearby: Gillette 106 mi · Laramie 114 mi · Sheridan 137 mi · Cheyenne 142 mi · Fort Collins 170 mi · Rock Springs 172 mi · Rapid City 176 mi · Estes Park 177 mi

United States travel facts

Power plugs: Type A / B; 120 V · 60 Hz
Prices: ≈ 100% of US; price level, 2025
GDP per capita: $90,027; 2025
Happiness: 6.8 / 10; World Happiness, 2025
Safe drinking water: 98%; of population, 2024
Homicide rate: 5.8; per 100k, 2023
Road deaths: 12.7; per 100k/yr, 2019
Income group: High; World Bank
Religion

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Casper (42.8666°, -106.3131°, elevation 5,118 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).

	Avg high (°F)	Avg low (°F)
1	34	17
2	34	17
3	33	16
4	33	16
5	33	15
6	32	15
7	32	15
8	32	15
9	31	14
10	31	14
11	31	14
12	31	13
13	30	13
14	30	13
15	30	13
16	30	12
17	29	12
18	29	12
19	29	12
20	29	11
21	29	11
22	28	11
23	28	11
24	28	11
25	28	11
26	28	11
27	28	11
28	28	11
29	28	11
30	28	11
31	28	11

	Clearer (%)	Cloudier (%)
1	61	39
2	61	39
3	59	41
4	59	41
5	59	41
6	59	41
7	59	41
8	59	41
9	59	41
10	59	41
11	59	41
12	59	41
13	59	41
14	60	40
15	60	40
16	60	40
17	60	40
18	60	40
19	60	40
20	60	40
21	61	39
22	61	39
23	61	39
24	61	39
25	61	39
26	61	39
27	60	40
28	60	40
29	60	40
30	59	41
31	59	41

	Rain chance (%)	Snow chance (%)
1	19	20
2	19	20
3	18	19
4	18	19
5	17	19
6	17	19
7	17	18
8	17	18
9	17	18
10	17	18
11	17	18
12	17	19
13	17	19
14	18	19
15	18	20
16	18	20
17	19	21
18	19	21
19	19	21
20	20	21
21	20	21
22	20	21
23	20	21
24	20	21
25	20	21
26	19	21
27	19	20
28	19	20
29	19	19
30	18	19
31	18	18

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°F)	Avg low (°F)
1	34	17
2	34	17
3	33	16
4	33	16
5	33	15
6	32	15
7	32	15
8	32	15
9	31	14
10	31	14
11	31	14
12	31	13
13	30	13
14	30	13
15	30	13
16	30	12
17	29	12
18	29	12
19	29	12
20	29	11
21	29	11
22	28	11
23	28	11
24	28	11
25	28	11
26	28	11
27	28	11
28	28	11
29	28	11
30	28	11
31	28	11

	Clearer (%)	Cloudier (%)
1	61	39
2	61	39
3	59	41
4	59	41
5	59	41
6	59	41
7	59	41
8	59	41
9	59	41
10	59	41
11	59	41
12	59	41
13	59	41
14	60	40
15	60	40
16	60	40
17	60	40
18	60	40
19	60	40
20	60	40
21	61	39
22	61	39
23	61	39
24	61	39
25	61	39
26	61	39
27	60	40
28	60	40
29	60	40
30	59	41
31	59	41

	Rain chance (%)	Snow chance (%)
1	19	20
2	19	20
3	18	19
4	18	19
5	17	19
6	17	19
7	17	18
8	17	18
9	17	18
10	17	18
11	17	18
12	17	19
13	17	19
14	18	19
15	18	20
16	18	20
17	19	21
18	19	21
19	19	21
20	20	21
21	20	21
22	20	21
23	20	21
24	20	21
25	20	21
26	19	21
27	19	20
28	19	20
29	19	19
30	18	19
31	18	18

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°F)	Avg low (°F)
1	34	17
2	34	17
3	33	16
4	33	16
5	33	15
6	32	15
7	32	15
8	32	15
9	31	14
10	31	14
11	31	14
12	31	13
13	30	13
14	30	13
15	30	13
16	30	12
17	29	12
18	29	12
19	29	12
20	29	11
21	29	11
22	28	11
23	28	11
24	28	11
25	28	11
26	28	11
27	28	11
28	28	11
29	28	11
30	28	11
31	28	11

	Clearer (%)	Cloudier (%)
1	61	39
2	61	39
3	59	41
4	59	41
5	59	41
6	59	41
7	59	41
8	59	41
9	59	41
10	59	41
11	59	41
12	59	41
13	59	41
14	60	40
15	60	40
16	60	40
17	60	40
18	60	40
19	60	40
20	60	40
21	61	39
22	61	39
23	61	39
24	61	39
25	61	39
26	61	39
27	60	40
28	60	40
29	60	40
30	59	41
31	59	41

	Rain chance (%)	Snow chance (%)
1	19	20
2	19	20
3	18	19
4	18	19
5	17	19
6	17	19
7	17	18
8	17	18
9	17	18
10	17	18
11	17	18
12	17	19
13	17	19
14	18	19
15	18	20
16	18	20
17	19	21
18	19	21
19	19	21
20	20	21
21	20	21
22	20	21
23	20	21
24	20	21
25	20	21
26	19	21
27	19	20
28	19	20
29	19	19
30	18	19
31	18	18

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100