Lewiston Weather in May
Average highs run from 73°F on May 1 to 81°F on May 31, and lows from 41°F to 47°F. Normal precipitation for the month is 1.69 in over about 8 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
- 77°F
- Average low
- 44°F
- Precipitation
- 1.69 in
- Record high
- 106°FMay 30, 1984
- Record low
- 22°FMay 6, 1964
- Chance of a freeze
- 26%
- Days of 90°F or more
- 3.8
- Daylight
- 13 h 58 min to 14 h 53 min
- Cloud cover
- 44%
- Humidity
- 74%
- Dew point
- 44°F
- Wind
- 3.8 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 | 73°F | 41°F | 94°F 1947 | 24°F 1913 | 26% | 0% |
| May 2 | 73°F | 41°F | 91°F 1945 | 26°F 1913 | 26% | 0% |
| May 3 | 73°F | 41°F | 93°F 2017 | 24°F 1950 | 26% | 0% |
| May 4 | 74°F | 41°F | 93°F 2017 | 25°F 1950 | 26% | 0% |
| May 5 | 74°F | 42°F | 95°F 1992 | 25°F 1975 | 25% | 0% |
| May 6 | 74°F | 42°F | 98°F 1987 | 22°F 1964 | 25% | 0% |
| May 7 | 75°F | 42°F | 102°F 1987 | 22°F 1950 | 25% | 0% |
| May 8 | 75°F | 42°F | 95°F 2001 | 28°F 1950 | 25% | 0% |
| May 9 | 75°F | 43°F | 99°F 1936 | 24°F 1922 | 24% | 0% |
| May 10 | 76°F | 43°F | 96°F 1969 | 24°F 1922 | 24% | 0% |
| May 11 | 76°F | 43°F | 99°F 1936 | 25°F 1943 | 24% | 0% |
| May 12 | 76°F | 43°F | 96°F 1987 | 27°F 1916 | 24% | 0% |
| May 13 | 77°F | 44°F | 98°F 1938 | 27°F 1916 | 24% | 0% |
| May 14 | 77°F | 44°F | 94°F 1973 | 24°F 1955 | 24% | 0% |
| May 15 | 77°F | 44°F | 97°F 1927 | 27°F 1999 | 23% | 0% |
| May 16 | 78°F | 44°F | 96°F 2006 | 26°F 1943 | 23% | 0% |
| May 17 | 78°F | 45°F | 100°F 2008 | 28°F 1943 | 23% | 0% |
| May 18 | 78°F | 45°F | 100°F 2008 | 27°F 1982 | 23% | 0% |
| May 19 | 78°F | 45°F | 99°F 2006 | 28°F 1974 | 23% | 0% |
| May 20 | 79°F | 45°F | 101°F 1919 | 28°F 1962 | 23% | 0% |
| May 21 | 79°F | 45°F | 101°F 1919 | 27°F 1971 | 22% | 0% |
| May 22 | 79°F | 45°F | 97°F 2001 | 28°F 1986 | 22% | 0% |
| May 23 | 79°F | 46°F | 102°F 1936 | 28°F 1944 | 22% | 0% |
| May 24 | 80°F | 46°F | 100°F 1936 | 29°F 1960 | 21% | 0% |
| May 25 | 80°F | 46°F | 101°F 1936 | 27°F 1920 | 21% | 0% |
| May 26 | 80°F | 46°F | 100°F 1982 | 24°F 1923 | 21% | 0% |
| May 27 | 80°F | 46°F | 98°F 1983 | 30°F 1922 | 20% | 0% |
| May 28 | 81°F | 46°F | 101°F 1983 | 28°F 1927 | 20% | 0% |
| May 29 | 81°F | 46°F | 100°F 1983 | 27°F 1927 | 19% | 0% |
| May 30 | 81°F | 46°F | 106°F 1984 | 30°F 1919 | 19% | 0% |
| May 31 | 81°F | 47°F | 106°F 1986 | 29°F 1919 | 19% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PDT).
- May 1
- sunrise 6:10 AM, sunset 8:08 PM
- May 31
- sunrise 5:43 AM, sunset 8:36 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00049026 (Trinity Rvr Hatchery), public domain. Records: NOAA GHCN-Daily, station USC00049490, 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.