Boulder Weather in August
Average highs run from 85°F on August 1 to 78°F on August 31, and lows from 49°F to 42°F. Normal precipitation for the month is 1.12 in over about 7 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
- 82°F
- Average low
- 46°F
- Precipitation
- 1.12 in
- Record high
- 99°FAug 3, 2000
- Record low
- 23°FAug 25, 1992
- Chance of a freeze
- 24%
- Days of 90°F or more
- 4.3
- Daylight
- 14 h 48 min to 13 h 21 min
- Cloud cover
- 46%
- Humidity
- 50%
- Dew point
- 42°F
- Wind
- 5.1 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation.
| Date | Normal high | Normal low | Record high | Record low | Chance wet |
|---|---|---|---|---|---|
| Aug 1 | 85°F | 49°F | 95°F 2000 | 34°F 2002 | 24% |
| Aug 2 | 85°F | 49°F | 95°F 1934 | 32°F 1937 | 24% |
| Aug 3 | 85°F | 49°F | 99°F 2000 | 34°F 1937 | 24% |
| Aug 4 | 85°F | 49°F | 96°F 1961 | 33°F 1996 | 24% |
| Aug 5 | 85°F | 49°F | 99°F 1961 | 34°F 1935 | 24% |
| Aug 6 | 85°F | 49°F | 97°F 1983 | 36°F 1969 | 23% |
| Aug 7 | 84°F | 48°F | 96°F 1983 | 33°F 1946 | 23% |
| Aug 8 | 84°F | 48°F | 92°F 1930 | 33°F 1946 | 23% |
| Aug 9 | 84°F | 48°F | 96°F 2000 | 31°F 1995 | 23% |
| Aug 10 | 84°F | 48°F | 96°F 1928 | 35°F 2016 | 23% |
| Aug 11 | 84°F | 48°F | 97°F 2018 | 33°F 1947 | 23% |
| Aug 12 | 83°F | 47°F | 99°F 1940 | 34°F 1987 | 23% |
| Aug 13 | 83°F | 47°F | 93°F 1940 | 32°F 1947 | 23% |
| Aug 14 | 83°F | 47°F | 93°F 1933 | 29°F 1959 | 23% |
| Aug 15 | 83°F | 47°F | 94°F 2023 | 34°F 1938 | 23% |
| Aug 16 | 82°F | 46°F | 93°F 1920 | 33°F 1935 | 23% |
| Aug 17 | 82°F | 46°F | 93°F 1919 | 30°F 1946 | 23% |
| Aug 18 | 82°F | 46°F | 93°F 1977 | 31°F 1995 | 23% |
| Aug 19 | 82°F | 46°F | 93°F 1942 | 30°F 1995 | 23% |
| Aug 20 | 81°F | 45°F | 91°F 1971 | 31°F 1938 | 23% |
| Aug 21 | 81°F | 45°F | 92°F 2009 | 29°F 1966 | 23% |
| Aug 22 | 81°F | 45°F | 94°F 1976 | 32°F 1966 | 23% |
| Aug 23 | 80°F | 45°F | 94°F 1969 | 30°F 1992 | 23% |
| Aug 24 | 80°F | 44°F | 95°F 1969 | 31°F 1910 | 23% |
| Aug 25 | 80°F | 44°F | 94°F 1981 | 23°F 1992 | 23% |
| Aug 26 | 79°F | 44°F | 91°F 1894 | 26°F 1992 | 23% |
| Aug 27 | 79°F | 44°F | 93°F 1924 | 29°F 1945 | 23% |
| Aug 28 | 79°F | 43°F | 93°F 1934 | 26°F 1960 | 23% |
| Aug 29 | 78°F | 43°F | 91°F 1998 | 27°F 1937 | 23% |
| Aug 30 | 78°F | 43°F | 89°F 1954 | 25°F 1965 | 23% |
| Aug 31 | 78°F | 42°F | 91°F 1955 | 27°F 2006 | 23% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (MDT).
- August 1
- sunrise 6:10 AM, sunset 8:58 PM
- August 31
- sunrise 6:48 AM, sunset 8:09 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00241008 (Boulder), public domain. Records: NOAA GHCN-Daily, station USW00024135, 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.