Jefferson County Weather in May
Average highs run from 59°F on May 1 to 68°F on May 31, and lows from 30°F to 40°F. Normal precipitation for the month is 1.86 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
- 35°F
- Precipitation
- 1.86 in
- Record high
- 90°FMay 28, 1919
- Record low
- 9°FMay 1, 1975
- Chance of a freeze
- 100%
- Daylight
- 14 h 22 min to 15 h 31 min
- Cloud cover
- 69%
- Humidity
- 64%
- Dew point
- 34°F
- Wind
- 6.0 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation.
| Date | Normal high | Normal low | Record high | Record low | Chance wet |
|---|---|---|---|---|---|
| May 1 | 59°F | 30°F | 80°F 1985 | 9°F 1975 | 29% |
| May 2 | 59°F | 31°F | 82°F 1985 | 11°F 1975 | 30% |
| May 3 | 60°F | 31°F | 81°F 1966 | 18°F 1942 | 30% |
| May 4 | 60°F | 31°F | 83°F 1966 | 15°F 1950 | 31% |
| May 5 | 60°F | 32°F | 82°F 1966 | 15°F 2010 | 31% |
| May 6 | 61°F | 32°F | 82°F 1966 | 16°F 1968 | 32% |
| May 7 | 61°F | 32°F | 82°F 1987 | 16°F 1965 | 32% |
| May 8 | 61°F | 33°F | 81°F 1987 | 9°F 1965 | 33% |
| May 9 | 62°F | 33°F | 79°F 1994 | 16°F 1916 | 33% |
| May 10 | 62°F | 33°F | 82°F 2025 | 18°F 1946 | 34% |
| May 11 | 62°F | 34°F | 81°F 1960 | 15°F 1967 | 34% |
| May 12 | 63°F | 34°F | 82°F 1960 | 16°F 1985 | 35% |
| May 13 | 63°F | 35°F | 84°F 1993 | 18°F 1983 | 36% |
| May 14 | 63°F | 35°F | 88°F 1936 | 18°F 1983 | 36% |
| May 15 | 64°F | 35°F | 83°F 2012 | 21°F 2004 | 37% |
| May 16 | 64°F | 36°F | 84°F 1988 | 21°F 1974 | 37% |
| May 17 | 64°F | 36°F | 82°F 1976 | 16°F 1896 | 38% |
| May 18 | 64°F | 36°F | 84°F 2009 | 21°F 1903 | 38% |
| May 19 | 65°F | 36°F | 85°F 1954 | 19°F 2026 | 39% |
| May 20 | 65°F | 37°F | 83°F 1919 | 23°F 2003 | 39% |
| May 21 | 65°F | 37°F | 84°F 1919 | 12°F 1938 | 40% |
| May 22 | 66°F | 37°F | 83°F 1919 | 19°F 1916 | 40% |
| May 23 | 66°F | 38°F | 84°F 1929 | 19°F 1916 | 41% |
| May 24 | 66°F | 38°F | 84°F 1928 | 20°F 1918 | 41% |
| May 25 | 66°F | 38°F | 85°F 1934 | 20°F 1950 | 41% |
| May 26 | 67°F | 39°F | 83°F 1934 | 22°F 1975 | 42% |
| May 27 | 67°F | 39°F | 87°F 1986 | 25°F 1973 | 42% |
| May 28 | 67°F | 39°F | 90°F 1919 | 21°F 1947 | 42% |
| May 29 | 67°F | 39°F | 87°F 1936 | 21°F 1947 | 42% |
| May 30 | 68°F | 39°F | 87°F 1936 | 24°F 1920 | 42% |
| May 31 | 68°F | 40°F | 87°F 2025 | 24°F 1950 | 42% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (MDT).
- May 1
- sunrise 6:15 AM, sunset 8:37 PM
- May 31
- sunrise 5:41 AM, sunset 9:12 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00241008 (Boulder), public domain. Records: NOAA GHCN-Daily, station USW00024135, 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.