Lewistown Weather in May
Average highs run from 69°F on May 1 to 78°F on May 31, and lows from 47°F to 58°F. Normal precipitation for the month is 5.06 in over about 12 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
- 73°F
- Average low
- 53°F
- Precipitation
- 5.06 in
- Record high
- 104°FMay 31, 1934
- Record low
- 30°FMay 3, 1976
- Chance of a freeze
- 15%
- Days of 90°F or more
- 0.5
- Daylight
- 13 h 55 min to 14 h 49 min
- Cloud cover
- 64%
- Humidity
- 76%
- Dew point
- 55°F
- Wind
- 9.8 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 | 69°F | 47°F | 87°F 1951 | 34°F 1960 | 39% | |
| May 2 | 69°F | 48°F | 90°F 1968 | 35°F 1967 | 39% | |
| May 3 | 69°F | 48°F | 88°F 1949 | 30°F 1976 | 39% | |
| May 4 | 70°F | 49°F | 90°F 1952 | 30°F 1954 | 39% | |
| May 5 | 70°F | 49°F | 92°F 1952 | 31°F 1990 | 38% | |
| May 6 | 70°F | 49°F | 88°F 1936 | 31°F 1944 | 38% | |
| May 7 | 70°F | 50°F | 88°F 1936 | 35°F 1960 | 38% | |
| May 8 | 71°F | 50°F | 91°F 2023 | 36°F 1960 | 38% | |
| May 9 | 71°F | 50°F | 92°F 1979 | 34°F 1966 | 38% | |
| May 10 | 71°F | 51°F | 90°F 2022 | 32°F 1966 | 38% | |
| May 11 | 72°F | 51°F | 92°F 2011 | 36°F 1952 | 38% | |
| May 12 | 72°F | 51°F | 93°F 2022 | 38°F 2013 | 38% | |
| May 13 | 72°F | 52°F | 93°F 2022 | 36°F 1989 | 37% | 0% |
| May 14 | 73°F | 52°F | 91°F 2022 | 38°F 1959 | 37% | 0% |
| May 15 | 73°F | 53°F | 93°F 1988 | 35°F 1959 | 37% | 0% |
| May 16 | 73°F | 53°F | 92°F 1977 | 38°F 1959 | 37% | 0% |
| May 17 | 74°F | 53°F | 89°F 1964 | 39°F 1973 | 37% | 0% |
| May 18 | 74°F | 54°F | 91°F 1996 | 38°F 2002 | 37% | 0% |
| May 19 | 74°F | 54°F | 91°F 1962 | 40°F 1968 | 37% | 0% |
| May 20 | 74°F | 54°F | 90°F 1941 | 38°F 1954 | 37% | 0% |
| May 21 | 75°F | 55°F | 92°F 1941 | 39°F 2002 | 37% | 0% |
| May 22 | 75°F | 55°F | 91°F 1956 | 38°F 1963 | 37% | 0% |
| May 23 | 75°F | 55°F | 91°F 1972 | 40°F 1996 | 36% | 0% |
| May 24 | 76°F | 56°F | 91°F 1939 | 41°F 1935 | 36% | 0% |
| May 25 | 76°F | 56°F | 91°F 1953 | 42°F 1979 | 36% | 0% |
| May 26 | 76°F | 56°F | 91°F 1953 | 38°F 1961 | 36% | 0% |
| May 27 | 77°F | 57°F | 93°F 1978 | 39°F 1992 | 36% | 0% |
| May 28 | 77°F | 57°F | 95°F 2018 | 42°F 1992 | 36% | 0% |
| May 29 | 77°F | 57°F | 97°F 1934 | 37°F 1947 | 36% | 0% |
| May 30 | 78°F | 58°F | 99°F 1934 | 41°F 1947 | 36% | 0% |
| May 31 | 78°F | 58°F | 104°F 1934 | 42°F 1972 | 35% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- May 1
- sunrise 6:07 AM, sunset 8:02 PM
- May 31
- sunrise 5:41 AM, sunset 8:30 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00238051 (Steffenville), public domain. Records: NOAA GHCN-Daily, station USC00233601, 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.