Casper weather in May: Casper, Wyoming: normal highs, lows, rain and records for May
Casper in May has a normal high of 67°F and a normal low of 37°F, a daily mean of 52°F, rising from 60°F on the 1st to 73°F by the 31st. Measurable precipitation falls on 11 days in a normal May, 2.21 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 19°C and low of 3°C, 56 mm of precipitation and 7 cm of snow in May.
- NOAA stationCasper-Natrona County Airport
- Station IDUSW00024089
- Location42.90°N 106.46°W
- Elevation5,338 ft (1,627 m)
- Population58,823
- Jan 35° 15°
- Feb 38° 15°
- Mar 49° 23°
- Apr 56° 28°
- May 67° 37°
- Jun 80° 45°
- Jul 89° 53°
- Aug 87° 51°
- Sep 76° 42°
- Oct 60° 31°
- Nov 46° 22°
- Dec 35° 15°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Casper in May?
The normal high is 67°F and the normal low 37°F, for a daily mean of 52.0°F. May is 9.7°F warmer than April and 10.5°F cooler than June. May is the 5th warmest month of the year in Casper and the wettest. Across the month the normal high rises 13°F, from 60°F on May 1 to 73°F on May 31. From one year to the next May's mean temperature typically moves about 3.0°F either way (NOAA's standard deviation), so roughly two Mays in three average between 49°F and 55°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 36%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| May 1 | 60°F | 32°F | 35% | 16% |
| May 8 | 63°F | 34°F | 35% | 17% |
| May 15 | 66°F | 37°F | 35% | 17% |
| May 22 | 69°F | 39°F | 36% | 17% |
| May 31 | 73°F | 42°F | 34% | 16% |
Every day of May: normal high, low and chance of precipitation (warmest afternoon May 31, coldest night May 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| May 1 | 60°F | 32°F | 35% | 16% | 14 h |
| May 2 | 61°F | 32°F | 35% | 16% | 14 h 10 min |
| May 3 | 61°F | 32°F | 35% | 16% | 14 h 10 min |
| May 4 | 62°F | 33°F | 35% | 16% | 14 h 10 min |
| May 5 | 62°F | 33°F | 35% | 16% | 14 h 10 min |
| May 6 | 62°F | 34°F | 35% | 16% | 14 h 20 min |
| May 7 | 63°F | 34°F | 35% | 17% | 14 h 20 min |
| May 8 | 63°F | 34°F | 35% | 17% | 14 h 20 min |
| May 9 | 64°F | 35°F | 35% | 17% | 14 h 20 min |
| May 10 | 64°F | 35°F | 35% | 17% | 14 h 30 min |
| May 11 | 65°F | 35°F | 35% | 17% | 14 h 30 min |
| May 12 | 65°F | 36°F | 35% | 17% | 14 h 30 min |
| May 13 | 66°F | 36°F | 35% | 17% | 14 h 30 min |
| May 14 | 66°F | 37°F | 35% | 17% | 14 h 30 min |
| May 15 | 66°F | 37°F | 35% | 17% | 14 h 40 min |
| May 16 | 67°F | 37°F | 35% | 17% | 14 h 40 min |
| May 17 | 67°F | 38°F | 36% | 17% | 14 h 40 min |
| May 18 | 68°F | 38°F | 36% | 17% | 14 h 40 min |
| May 19 | 68°F | 38°F | 36% | 17% | 14 h 40 min |
| May 20 | 69°F | 39°F | 36% | 17% | 14 h 50 min |
| May 21 | 69°F | 39°F | 36% | 17% | 14 h 50 min |
| May 22 | 69°F | 39°F | 36% | 17% | 14 h 50 min |
| May 23 | 70°F | 40°F | 35% | 17% | 14 h 50 min |
| May 24 | 70°F | 40°F | 35% | 17% | 14 h 50 min |
| May 25 | 71°F | 40°F | 35% | 17% | 15 h |
| May 26 | 71°F | 41°F | 35% | 17% | 15 h |
| May 27 | 72°F | 41°F | 35% | 17% | 15 h |
| May 28 | 72°F | 41°F | 34% | 17% | 15 h |
| May 29 | 72°F | 41°F | 34% | 17% | 15 h |
| May 30 | 73°F | 42°F | 34% | 16% | 15 h |
| May 31 | 73°F | 42°F | 34% | 16% | 15 h 10 min |
- Normal high
- 67°FMay average
- Normal low
- 37°FMay average
- Precipitation
- 2.21 inmonth total
- Days with precipitation
- 110.01 inch or more
- Snowfall
- 2.6 inmonth total
- Nights at 32°F or colder
- 8
- Daylight
- 14 h to 15 h 10 minMay 1 to May 31
- Days at 70°F or more
- 14
- Days at 80°F or more
- 5
- Sunshine
- 75%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00024089; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in Casper in May?
On a given May day the chance of 0.01 inch or more is 35% on average, highest around May 20 (36%). In all, 2.21 in falls on 11 days of a normal May.
In a normal May in Casper, 8 nights fall to freezing and snowfall averages 2.6 inches.
Snow falls on 2 days in a normal May, and an inch or more covers the ground on 1 day.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00024089.
How humid and windy is Casper in May?
At 3 p.m. the normal temperature is 70°F with 31% relative humidity and a dew point of 37°F; at 6 a.m. it is 49°F with 74% humidity. The wind averages 10.0 mph, most often from the west-northwest in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 49°F | 41°F | 74% | 7.0 mph | 68% |
| 9 a.m. | 61°F | 41°F | 49% | 10.8 mph | 71% |
| noon | 68°F | 39°F | 34% | 12.5 mph | 65% |
| 3 p.m. | 70°F | 37°F | 31% | 12.8 mph | 63% |
| 6 p.m. | 66°F | 39°F | 37% | 12.3 mph | 63% |
| 9 p.m. | 55°F | 41°F | 59% | 9.2 mph | 66% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00024089. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for May in Casper?
The warmest May temperature on Casper's official record (since 1939) is 95°F, on May 29, 2003; the coldest is 16°F, on May 12, 1953. The wettest May brought 6.46 in (1978); the snowiest, 32.8 inches (1946).
The May mean against the 1991-2020 normal of 52.0°F: 2021 51.3°F (−0.7), 2022 48.3°F (−3.7), 2023 55.2°F (+3.2), 2024 49.8°F (−2.2), 2025 53.0°F (+1.0), 2026 53.0°F (+1.0). 3 of 6 ran warmer than normal.
| May | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 51.3°F | −0.7°F | 0.60 in |
| 2022 | 48.3°F | −3.7°F | 2.61 in |
| 2023 | 55.2°F | +3.2°F | 2.03 in |
| 2024 | 49.8°F | −2.2°F | 2.44 in |
| 2025 | 53.0°F | +1.0°F | 1.28 in |
| 2026 | 53.0°F | +1.0°F | 1.67 in |
Source: records: ACIS, NWS threaded record CPRthr; recent months: ACIS, station USW00024089. Records and recent months use complete months only.
How does May in Casper compare across Wyoming?
Across the 71 places PlainClimate covers in Wyoming, May normal highs run from 55°F in Sundance to 73°F in Basin; Casper's is 67°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.