Ada County Weather in May
Average highs run from 67°F on May 1 to 76°F on May 31, and lows from 43°F to 51°F. Normal precipitation for the month is 1.45 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
- 72°F
- Average low
- 48°F
- Precipitation
- 1.45 in
- Record high
- 100°FMay 31, 2025
- Record low
- 22°FMay 5, 1982
- Chance of a freeze
- 29%
- Days of 90°F or more
- 1.4
- Daylight
- 14 h 09 min to 15 h 11 min
- Cloud cover
- 58%
- Humidity
- 52%
- Dew point
- 38°F
- Wind
- 7.4 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 | 43°F | 88°F 1985 | 27°F 1954 | 28% | 0% |
| May 2 | 68°F | 44°F | 91°F 1947 | 23°F 1988 | 28% | 0% |
| May 3 | 68°F | 44°F | 90°F 1966 | 28°F 1959 | 28% | 0% |
| May 4 | 69°F | 44°F | 93°F 1966 | 26°F 1982 | 28% | 0% |
| May 5 | 69°F | 44°F | 94°F 1966 | 22°F 1982 | 28% | 0% |
| May 6 | 69°F | 45°F | 95°F 1947 | 27°F 1964 | 28% | 0% |
| May 7 | 70°F | 45°F | 93°F 1987 | 26°F 1981 | 28% | 0% |
| May 8 | 70°F | 45°F | 94°F 1987 | 28°F 2002 | 28% | 0% |
| May 9 | 70°F | 46°F | 88°F 2025 | 29°F 1999 | 28% | 0% |
| May 10 | 71°F | 46°F | 92°F 1940 | 27°F 1999 | 28% | 0% |
| May 11 | 71°F | 46°F | 93°F 1941 | 27°F 1943 | 28% | 0% |
| May 12 | 71°F | 47°F | 96°F 2026 | 24°F 1985 | 28% | 0% |
| May 13 | 72°F | 47°F | 95°F 2013 | 26°F 1974 | 27% | 0% |
| May 14 | 72°F | 47°F | 91°F 1975 | 28°F 1986 | 27% | 0% |
| May 15 | 72°F | 48°F | 93°F 2006 | 28°F 1990 | 27% | 0% |
| May 16 | 73°F | 48°F | 94°F 2006 | 28°F 1974 | 27% | 0% |
| May 17 | 73°F | 48°F | 94°F 2008 | 30°F 1942 | 27% | 0% |
| May 18 | 73°F | 48°F | 95°F 2009 | 30°F 1971 | 27% | 0% |
| May 19 | 73°F | 49°F | 90°F 1954 | 28°F 1960 | 27% | 0% |
| May 20 | 74°F | 49°F | 94°F 1958 | 33°F 1971 | 27% | 0% |
| May 21 | 74°F | 49°F | 91°F 2023 | 33°F 1960 | 27% | 0% |
| May 22 | 74°F | 49°F | 93°F 1988 | 28°F 1960 | 26% | 0% |
| May 23 | 75°F | 50°F | 95°F 2001 | 32°F 1944 | 26% | 0% |
| May 24 | 75°F | 50°F | 97°F 2001 | 33°F 1975 | 26% | 0% |
| May 25 | 75°F | 50°F | 96°F 1961 | 30°F 1975 | 26% | 0% |
| May 26 | 75°F | 50°F | 98°F 1966 | 33°F 1973 | 25% | 0% |
| May 27 | 75°F | 50°F | 94°F 1983 | 32°F 1991 | 25% | 0% |
| May 28 | 76°F | 51°F | 99°F 2003 | 34°F 1982 | 25% | 0% |
| May 29 | 76°F | 51°F | 95°F 1986 | 32°F 1976 | 24% | 0% |
| May 30 | 76°F | 51°F | 98°F 1986 | 33°F 1979 | 24% | 0% |
| May 31 | 76°F | 51°F | 100°F 2025 | 32°F 1955 | 24% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MDT).
- May 1
- sunrise 6:38 AM, sunset 8:47 PM
- May 31
- sunrise 6:07 AM, sunset 9:18 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00024131 (Boise Air Terminal), public domain. Records: NOAA GHCN-Daily, station USW00024131, 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.