Richland Weather in May
Average highs run from 70°F on May 1 to 77°F on May 31, and lows from 44°F to 52°F. Normal precipitation for the month is 0.63 in over about 7 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
- 74°F
- Average low
- 48°F
- Precipitation
- 0.63 in
- Record high
- 105°FMay 26, 1947
- Record low
- 30°FMay 1, 1954
- Chance of a freeze
- 2%
- Days of 90°F or more
- 1.3
- Daylight
- 14 h 23 min to 15 h 32 min
- Cloud cover
- 58%
- Humidity
- 51%
- Dew point
- 40°F
- Wind
- 7.6 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 | 70°F | 44°F | 91°F 1957 | 30°F 1954 | 22% | 0% |
| May 2 | 70°F | 45°F | 92°F 1946 | 33°F 1954 | 22% | 0% |
| May 3 | 71°F | 45°F | 92°F 1945 | 35°F 2006 | 22% | 0% |
| May 4 | 71°F | 45°F | 90°F 1966 | 34°F 1962 | 22% | 0% |
| May 5 | 71°F | 45°F | 93°F 1966 | 34°F 1965 | 22% | 0% |
| May 6 | 72°F | 46°F | 98°F 1947 | 35°F 1950 | 22% | 0% |
| May 7 | 72°F | 46°F | 95°F 1987 | 34°F 1984 | 22% | 0% |
| May 8 | 72°F | 46°F | 96°F 1987 | 33°F 2002 | 22% | 0% |
| May 9 | 72°F | 47°F | 95°F 1987 | 33°F 1999 | 22% | 0% |
| May 10 | 73°F | 47°F | 97°F 1949 | 34°F 1999 | 22% | 0% |
| May 11 | 73°F | 47°F | 98°F 1949 | 34°F 1999 | 23% | 0% |
| May 12 | 73°F | 47°F | 100°F 1949 | 38°F 2012 | 23% | 0% |
| May 13 | 74°F | 48°F | 100°F 1949 | 37°F 1983 | 23% | 0% |
| May 14 | 74°F | 48°F | 95°F 1949 | 34°F 1955 | 23% | 0% |
| May 15 | 74°F | 48°F | 94°F 1973 | 39°F 1974 | 23% | 0% |
| May 16 | 74°F | 48°F | 96°F 2006 | 38°F 1983 | 23% | 0% |
| May 17 | 74°F | 49°F | 96°F 2006 | 38°F 1974 | 23% | 0% |
| May 18 | 75°F | 49°F | 98°F 1956 | 37°F 1965 | 23% | 0% |
| May 19 | 75°F | 49°F | 98°F 1954 | 36°F 2003 | 23% | 0% |
| May 20 | 75°F | 50°F | 101°F 1947 | 42°F 1950 | 23% | 0% |
| May 21 | 75°F | 50°F | 96°F 1958 | 39°F 1960 | 23% | 0% |
| May 22 | 75°F | 50°F | 98°F 1958 | 38°F 1960 | 23% | 0% |
| May 23 | 76°F | 50°F | 100°F 1958 | 38°F 1964 | 23% | 0% |
| May 24 | 76°F | 50°F | 98°F 1947 | 39°F 1986 | 23% | 0% |
| May 25 | 76°F | 51°F | 104°F 1947 | 41°F 1964 | 23% | 0% |
| May 26 | 76°F | 51°F | 105°F 1947 | 42°F 1967 | 22% | 0% |
| May 27 | 76°F | 51°F | 102°F 1958 | 39°F 1989 | 22% | 0% |
| May 28 | 76°F | 51°F | 94°F 1952 | 39°F 1976 | 22% | 0% |
| May 29 | 77°F | 52°F | 101°F 1983 | 40°F 1951 | 22% | 0% |
| May 30 | 77°F | 52°F | 102°F 1986 | 40°F 1950 | 22% | 0% |
| May 31 | 77°F | 52°F | 104°F 1986 | 42°F 1950 | 21% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PDT).
- May 1
- sunrise 5:43 AM, sunset 8:06 PM
- May 31
- sunrise 5:09 AM, sunset 8:41 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00457015 (Richland), public domain. Records: NOAA GHCN-Daily, station USC00457015, 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.