Fairfax Weather in May
Average highs run from 67°F on May 1 to 78°F on May 31, and lows from 45°F to 57°F.
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
- 72°F
- Average low
- 51°F
- Snowfall
- 0.1 in
- Record high
- 108°FMay 30, 1934
- Record low
- 27°FMay 9, 1923
- Chance of a freeze
- 17%
- Days of 90°F or more
- 0.5
- Daylight
- 13 h 56 min to 14 h 51 min
- Cloud cover
- 62%
- Humidity
- 72%
- Dew point
- 53°F
- Wind
- 11.2 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 | 67°F | 45°F | 91°F 1959 | 31°F 1950 | 1% | |
| May 2 | 67°F | 45°F | 91°F 1968 | 30°F 1961 | 1% | |
| May 3 | 68°F | 46°F | 90°F 1968 | 29°F 1976 | 1% | |
| May 4 | 68°F | 46°F | 93°F 1950 | 30°F 1954 | 1% | |
| May 5 | 68°F | 46°F | 98°F 1940 | 29°F 1944 | 1% | |
| May 6 | 68°F | 47°F | 94°F 1916 | 28°F 1944 | 1% | |
| May 7 | 69°F | 47°F | 95°F 2014 | 30°F 1989 | 1% | |
| May 8 | 69°F | 48°F | 94°F 1934 | 34°F 1980 | 1% | |
| May 9 | 70°F | 48°F | 97°F 2011 | 27°F 1923 | 1% | |
| May 10 | 70°F | 49°F | 94°F 2011 | 36°F 1945 | 0% | |
| May 11 | 70°F | 49°F | 99°F 2000 | 30°F 1946 | 0% | |
| May 12 | 71°F | 49°F | 95°F 1956 | 34°F 1946 | 0% | |
| May 13 | 71°F | 50°F | 95°F 1915 | 33°F 1923 | 0% | |
| May 14 | 71°F | 50°F | 96°F 1941 | 34°F 1997 | 0% | |
| May 15 | 72°F | 51°F | 95°F 1944 | 35°F 1926 | 0% | |
| May 16 | 72°F | 51°F | 93°F 1944 | 32°F 2014 | 0% | |
| May 17 | 72°F | 52°F | 91°F 1917 | 36°F 1945 | 0% | |
| May 18 | 73°F | 52°F | 94°F 1996 | 33°F 1941 | 0% | |
| May 19 | 73°F | 52°F | 95°F 1944 | 33°F 1945 | 0% | |
| May 20 | 74°F | 53°F | 97°F 1925 | 32°F 1931 | 0% | |
| May 21 | 74°F | 53°F | 94°F 1956 | 32°F 1931 | 0% | |
| May 22 | 74°F | 54°F | 104°F 1925 | 34°F 2022 | 0% | |
| May 23 | 75°F | 54°F | 95°F 1960 | 38°F 1917 | 0% | |
| May 24 | 75°F | 55°F | 99°F 1939 | 38°F 1992 | 0% | |
| May 25 | 75°F | 55°F | 97°F 1926 | 30°F 1925 | 0% | |
| May 26 | 76°F | 55°F | 101°F 2018 | 40°F 1925 | 0% | |
| May 27 | 76°F | 56°F | 98°F 2018 | 35°F 1992 | 0% | |
| May 28 | 77°F | 56°F | 96°F 2018 | 34°F 1992 | 0% | |
| May 29 | 77°F | 57°F | 100°F 1934 | 32°F 1947 | 0% | |
| May 30 | 77°F | 57°F | 108°F 1934 | 38°F 1930 | 0% | |
| May 31 | 78°F | 57°F | 105°F 1934 | 30°F 1947 | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- May 1
- sunrise 6:21 AM, sunset 8:17 PM
- May 31
- sunrise 5:54 AM, sunset 8:45 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00014945 (Tarkio), public domain. Records: NOAA GHCN-Daily, station USW00094957, 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.