Fairfax Weather in May
Average highs run from 63°F on May 1 to 75°F on May 31, and lows from 39°F to 53°F. Normal precipitation for the month is 4.10 in over about 11 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
- 69°F
- Average low
- 46°F
- Precipitation
- 4.10 in
- Snowfall
- 0.1 in
- Record high
- 107°FMay 31, 1934
- Record low
- 21°FMay 3, 1909
- Chance of a freeze
- 45%
- Days of 90°F or more
- 1.4
- Daylight
- 14 h 15 min to 15 h 18 min
- Cloud cover
- 65%
- Humidity
- 70%
- Dew point
- 47°F
- Wind
- 11.6 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 | 63°F | 39°F | 98°F 1959 | 24°F 1909 | 32% | 2% |
| May 2 | 64°F | 40°F | 93°F 1959 | 25°F 1908 | 32% | 2% |
| May 3 | 64°F | 40°F | 96°F 1949 | 21°F 1909 | 32% | 1% |
| May 4 | 64°F | 41°F | 93°F 1952 | 22°F 1967 | 32% | 1% |
| May 5 | 65°F | 41°F | 91°F 1909 | 25°F 1929 | 33% | 1% |
| May 6 | 65°F | 42°F | 92°F 1934 | 28°F 1931 | 33% | 1% |
| May 7 | 66°F | 42°F | 93°F 1990 | 26°F 1954 | 33% | 1% |
| May 8 | 66°F | 42°F | 95°F 1934 | 27°F 1954 | 33% | 1% |
| May 9 | 66°F | 43°F | 94°F 1987 | 27°F 1945 | 33% | 1% |
| May 10 | 67°F | 43°F | 96°F 1987 | 28°F 1909 | 33% | 1% |
| May 11 | 67°F | 44°F | 92°F 2025 | 21°F 1946 | 34% | 1% |
| May 12 | 68°F | 44°F | 93°F 2022 | 25°F 1946 | 34% | 1% |
| May 13 | 68°F | 45°F | 94°F 1932 | 27°F 1918 | 34% | 1% |
| May 14 | 68°F | 45°F | 99°F 1932 | 31°F 2004 | 34% | 0% |
| May 15 | 69°F | 46°F | 97°F 2001 | 30°F 2004 | 34% | 0% |
| May 16 | 69°F | 46°F | 96°F 1934 | 30°F 1929 | 34% | 0% |
| May 17 | 70°F | 47°F | 98°F 1934 | 28°F 1930 | 34% | 0% |
| May 18 | 70°F | 47°F | 100°F 1998 | 33°F 1968 | 34% | 0% |
| May 19 | 70°F | 48°F | 104°F 1934 | 33°F 1929 | 34% | 0% |
| May 20 | 71°F | 48°F | 100°F 1934 | 30°F 1907 | 34% | 0% |
| May 21 | 71°F | 49°F | 95°F 1934 | 35°F 1931 | 34% | 0% |
| May 22 | 72°F | 49°F | 93°F 1939 | 32°F 1917 | 34% | 0% |
| May 23 | 72°F | 50°F | 90°F 1932 | 34°F 1958 | 34% | 0% |
| May 24 | 72°F | 50°F | 95°F 2010 | 35°F 1930 | 35% | 0% |
| May 25 | 73°F | 51°F | 95°F 1967 | 38°F 1913 | 35% | 0% |
| May 26 | 73°F | 51°F | 94°F 1911 | 35°F 1992 | 35% | 0% |
| May 27 | 73°F | 52°F | 95°F 1931 | 32°F 1907 | 35% | 0% |
| May 28 | 74°F | 52°F | 101°F 1934 | 34°F 1965 | 35% | 0% |
| May 29 | 74°F | 53°F | 100°F 1934 | 30°F 1947 | 34% | 0% |
| May 30 | 74°F | 53°F | 105°F 1934 | 34°F 1947 | 34% | 0% |
| May 31 | 75°F | 53°F | 107°F 1934 | 38°F 1908 | 34% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- May 1
- sunrise 6:09 AM, sunset 8:24 PM
- May 31
- sunrise 5:38 AM, sunset 8:56 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00216839 (Redwood Falls), public domain. Records: NOAA GHCN-Daily, station USW00014992, 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.