Casper weather in May

In May, Casper sees average daytime highs of 62°F and overnight lows near 39°F, with 2.7 in of precipitation across 11.1 wet days and about 14.4 hours of daylight. It is the 5th-warmest and 1st-wettest month of the year here.

Highs climb over the month, from about 56°F in the first days to 67°F by the end. The sky is clear or mostly clear about 25% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 54 min at the start of May to 14 h 54 min by month's end. Set against the rest of the year, May is Casper's 11th-clearest and 9th-windiest month. For the whole year in context, see Casper's year-round climate.

Daytime high
62°
5th warmest
Overnight low
39°
8th coldest
Precipitation
2.7 in
11.1 wet days
Daylight
14 h 24 min
4:48 AM – 7:15 PM
Cloud cover
61%
11th clearest
Wind
8 mph
9th windiest
Solar energy
6.9 kWh/m²
Travel score
5.0
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.

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 56°F in the first days to 67°F by the end.

A typical May day in Casper reaches about 62°F in the afternoon and slips back to 39°F overnight — a 23°F spread between the day's warmth and the night's chill. On most days the high lands between 47°F and 76°F. Set against its neighbours, May runs about 11°F warmer than April and about 13°F cooler than June.

20°40°60°80°151015202531
Avg high (°F)Avg low (°F)
15533
25533
35634
45634
55735
65735
75835
85836
95936
105937
116037
126038
136138
146139
156239
166240
176240
186340
196341
206441
216442
226442
236542
246542
256543
266643
276643
286744
296744
306844
316845

How May really feels in Casper

Once humidity and wind are folded in, May averages 0 days that feel above 90°F and 12 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
12
wind chill below the day's low

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

Casper weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan29° / 12°0.85.65.79.20.0
Feb32° / 13°1.05.95.810.20.0
Mar42° / 22°1.57.1611.60.5
Apr50° / 29°2.310.8713.12.3
May62° / 39°2.711.12.314.45.0
Jun75° / 49°1.46.30.115.17.5
Jul84° / 56°0.74.5014.86.5
Aug82° / 55°0.64.1013.87.3
Sep71° / 46°1.15.60.712.37.5
Oct55° / 33°1.874.110.84.0
Nov41° / 22°1.15.75.59.50.4
Dec30° / 13°0.95.66.18.90.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 21% of May, with mostly cloudy or overcast conditions the remaining 54%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14555
24555
34555
44555
54555
64555
74555
84654
94753
104753
114654
124555
134555
144555
154555
164654
174555
184555
194555
204456
214555
224654
234654
244654
254753
264852
274951
285050
295050
305149
315347

Chance of precipitation in May

Any precipitationSnow

Casper gets around 2.7 in of rain and snow over 11.1 wet days in May, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 36% and peaks near 39% on the wettest days, and about 2 days bring snow. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
13918
23917
33916
43916
53915
63914
73813
83812
93711
103710
113710
12379
13379
14378
15378
16377
17377
18376
19376
20365
21365
22364
23354
24354
25343
26333
27323
28312
29302
30292
31281

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

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

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in May

Winds average 8 mph in May.

Across May, daily wind ranges from about 8 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
18light breeze
28light breeze
38light breeze
48light breeze
58light breeze
68light breeze
78light breeze
88light breeze
98light breeze
108light breeze
118light breeze
128light breeze
138light breeze
148light breeze
158light breeze
168light breeze
178light breeze
188light breeze
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze
318light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 54 min at the start of May to 14 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 60 minutes over May. Sunrise moves from 5:07 AM to 4:36 AM, and sunset from 6:58 PM to 7:29 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.95:076:58
213.95:056:59
313.95:047:00
414.05:037:01
514.05:017:03
614.15:007:04
714.14:597:05
814.14:577:06
914.24:567:07
1014.24:557:08
1114.34:547:09
1214.34:537:10
1314.34:517:12
1414.44:507:13
1514.44:497:14
1614.44:487:15
1714.54:477:16
1814.54:467:17
1914.54:457:18
2014.64:447:19
2114.64:437:20
2214.64:427:21
2314.74:427:22
2414.74:417:23
2514.74:407:24
2614.84:397:25
2714.84:387:26
2814.84:387:27
2914.84:377:28
3014.94:377:29
3114.94:367:29

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 6.9 kWh/m².

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 — May's 6.9 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
16.6Intense
26.7Intense
36.7Intense
46.7Intense
56.7Intense
66.7Intense
76.8Intense
86.8Intense
96.8Intense
106.8Intense
116.8Intense
126.8Intense
136.8Intense
146.9Intense
156.9Intense
166.9Intense
176.9Intense
186.9Intense
196.9Intense
206.9Intense
216.9Intense
227.0Intense
237.0Intense
247.0Intense
257.0Intense
267.1Intense
277.1Intense
287.1Intense
297.2Intense
307.2Intense
317.2Intense
Planning a trip in May

Is May a good time to visit Casper?

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

5.0
Sightseeing
5th-best month of the year
1.3
Beach & pool
5th-best month of the year

May is a reasonable time to visit Casper for sightseeing.

What to pack for Casper in May

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

In May, Casper sees daytime highs around 62°F and nights near 39°F. Pack sun protection. Worth having: a warm layer and rain gear. About 11 days see rain.

sun protectiona warm layerrain gear

UV index in Casper in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 — enough to warrant sun protection. 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 11UV 10Dec 20UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5High
Apr6High
May8Very high
Jun10Very high
Jul10Very high
Aug8Very high
Sep7High
Oct4Moderate
Nov3Moderate
Dec2Low
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
10 miles
3,173 ft
50 miles
4,770 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
May 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
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

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).