Lewistown Weather in August
Average highs run from 86°F on August 1 to 82°F on August 31, and lows from 65°F to 60°F. Normal precipitation for the month is 3.88 in over about 8 wet days.
August day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
August at a glance
- Average high
- 84°F
- Average low
- 64°F
- Precipitation
- 3.88 in
- Record high
- 110°FAug 9, 1934
- Record low
- 40°FAug 31, 1999
- Chance of a freeze
- 0%
- Days of 90°F or more
- 9.0
- Daylight
- 14 h 15 min to 13 h 06 min
- Cloud cover
- 49%
- Humidity
- 70%
- Dew point
- 64°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 |
|---|---|---|---|---|---|---|
| Aug 1 | 86°F | 65°F | 101°F 1988 | 54°F 1968 | 28% | 0% |
| Aug 2 | 86°F | 65°F | 104°F 1934 | 56°F 1973 | 28% | 0% |
| Aug 3 | 86°F | 65°F | 102°F 1964 | 53°F 1950 | 28% | 0% |
| Aug 4 | 86°F | 65°F | 102°F 1934 | 53°F 1978 | 28% | 0% |
| Aug 5 | 86°F | 65°F | 100°F 1934 | 53°F 1948 | 28% | 0% |
| Aug 6 | 85°F | 65°F | 107°F 1934 | 51°F 1994 | 28% | 0% |
| Aug 7 | 85°F | 65°F | 104°F 1934 | 49°F 2004 | 28% | 0% |
| Aug 8 | 85°F | 65°F | 109°F 1934 | 54°F 1975 | 28% | 0% |
| Aug 9 | 85°F | 65°F | 110°F 1934 | 50°F 2004 | 28% | 0% |
| Aug 10 | 85°F | 65°F | 106°F 1934 | 52°F 2004 | 27% | 0% |
| Aug 11 | 85°F | 65°F | 103°F 1941 | 43°F 2004 | 27% | 0% |
| Aug 12 | 85°F | 64°F | 103°F 1936 | 42°F 2004 | 27% | 0% |
| Aug 13 | 85°F | 64°F | 106°F 1936 | 46°F 1964 | 27% | 0% |
| Aug 14 | 85°F | 64°F | 108°F 1936 | 51°F 2004 | 27% | 0% |
| Aug 15 | 85°F | 64°F | 102°F 1936 | 51°F 1992 | 27% | 0% |
| Aug 16 | 85°F | 64°F | 105°F 1936 | 52°F 1992 | 27% | 0% |
| Aug 17 | 84°F | 64°F | 103°F 1936 | 52°F 1943 | 27% | 0% |
| Aug 18 | 84°F | 64°F | 107°F 1936 | 52°F 1943 | 26% | 0% |
| Aug 19 | 84°F | 63°F | 107°F 1936 | 51°F 1950 | 26% | 0% |
| Aug 20 | 84°F | 63°F | 101°F 1936 | 44°F 1950 | 26% | 0% |
| Aug 21 | 84°F | 63°F | 104°F 1936 | 47°F 1950 | 26% | 0% |
| Aug 22 | 84°F | 63°F | 105°F 1936 | 53°F 1950 | 26% | 0% |
| Aug 23 | 84°F | 63°F | 102°F 1936 | 49°F 1966 | 25% | 0% |
| Aug 24 | 83°F | 62°F | 106°F 1936 | 48°F 1942 | 25% | 0% |
| Aug 25 | 83°F | 62°F | 104°F 1936 | 49°F 1958 | 25% | 0% |
| Aug 26 | 83°F | 62°F | 106°F 1936 | 49°F 1967 | 25% | 0% |
| Aug 27 | 83°F | 62°F | 101°F 2003 | 50°F 1971 | 25% | 0% |
| Aug 28 | 83°F | 61°F | 100°F 1983 | 43°F 1986 | 24% | 0% |
| Aug 29 | 83°F | 61°F | 102°F 1984 | 46°F 1986 | 24% | 0% |
| Aug 30 | 82°F | 61°F | 105°F 1984 | 50°F 1946 | 24% | 0% |
| Aug 31 | 82°F | 60°F | 100°F 1953 | 40°F 1999 | 24% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- August 1
- sunrise 6:06 AM, sunset 8:21 PM
- August 31
- sunrise 6:34 AM, sunset 7:40 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.