Spearfish Weather in May
Average highs run from 59°F on May 1 to 70°F on May 31, and lows from 36°F to 47°F. Normal precipitation for the month is 3.72 in over about 12 wet days.
May day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
May at a glance
- Average high
- 64°F
- Average low
- 42°F
- Precipitation
- 3.72 in
- Snowfall
- 2.3 in
- Record high
- 96°FMay 14, 2001
- Record low
- 11°FMay 1, 1909
- Chance of a freeze
- 85%
- Daylight
- 14 h 14 min to 15 h 19 min
- Cloud cover
- 64%
- Humidity
- 60%
- Dew point
- 37°F
- Wind
- 8.3 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| May 1 | 59°F | 36°F | 87°F 2001 | 11°F 1909 | 34% | 4% |
| May 2 | 59°F | 37°F | 87°F 1952 | 19°F 1976 | 34% | 4% |
| May 3 | 60°F | 37°F | 90°F 1952 | 14°F 1954 | 34% | 4% |
| May 4 | 60°F | 37°F | 89°F 1936 | 20°F 1920 | 35% | 4% |
| May 5 | 60°F | 38°F | 93°F 1936 | 21°F 1967 | 35% | 3% |
| May 6 | 61°F | 38°F | 86°F 1911 | 26°F 1960 | 35% | 3% |
| May 7 | 61°F | 38°F | 92°F 1934 | 23°F 1980 | 36% | 3% |
| May 8 | 61°F | 39°F | 92°F 1934 | 19°F 1929 | 36% | 3% |
| May 9 | 62°F | 39°F | 90°F 1934 | 24°F 1984 | 36% | 3% |
| May 10 | 62°F | 40°F | 88°F 1961 | 25°F 1945 | 37% | 2% |
| May 11 | 63°F | 40°F | 89°F 1940 | 13°F 1943 | 37% | 2% |
| May 12 | 63°F | 40°F | 93°F 1900 | 16°F 1943 | 37% | 2% |
| May 13 | 63°F | 41°F | 92°F 2001 | 21°F 1920 | 37% | 2% |
| May 14 | 64°F | 41°F | 96°F 2001 | 23°F 1907 | 38% | 2% |
| May 15 | 64°F | 42°F | 95°F 1936 | 29°F 1920 | 38% | 2% |
| May 16 | 64°F | 42°F | 92°F 1978 | 21°F 1920 | 38% | 2% |
| May 17 | 65°F | 42°F | 93°F 1893 | 29°F 1942 | 38% | 2% |
| May 18 | 65°F | 43°F | 90°F 1988 | 28°F 1915 | 39% | 1% |
| May 19 | 65°F | 43°F | 95°F 2009 | 29°F 1942 | 39% | 1% |
| May 20 | 66°F | 43°F | 95°F 2009 | 27°F 1908 | 39% | 1% |
| May 21 | 66°F | 44°F | 91°F 1964 | 19°F 1908 | 40% | 1% |
| May 22 | 66°F | 44°F | 93°F 1980 | 26°F 1920 | 40% | 1% |
| May 23 | 67°F | 45°F | 87°F 1931 | 28°F 1920 | 40% | 1% |
| May 24 | 67°F | 45°F | 89°F 1929 | 28°F 1924 | 40% | 1% |
| May 25 | 68°F | 45°F | 92°F 1931 | 30°F 1992 | 41% | 1% |
| May 26 | 68°F | 46°F | 92°F 1934 | 25°F 1920 | 41% | 1% |
| May 27 | 68°F | 46°F | 96°F 1969 | 28°F 1920 | 41% | 1% |
| May 28 | 69°F | 46°F | 95°F 1934 | 28°F 1947 | 41% | 1% |
| May 29 | 69°F | 47°F | 95°F 1934 | 22°F 1947 | 42% | 1% |
| May 30 | 69°F | 47°F | 94°F 1939 | 31°F 1947 | 42% | 0% |
| May 31 | 70°F | 47°F | 93°F 1933 | 30°F 1917 | 42% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MDT).
- May 1
- sunrise 5:46 AM, sunset 8:00 PM
- May 31
- sunrise 5:14 AM, sunset 8:33 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00397882 (Spearfish), public domain. Records: NOAA GHCN-Daily, station USC00397882, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.