Ottawa Weather in August
Average highs run from 90°F on August 1 to 85°F on August 31, and lows from 67°F to 62°F. Normal precipitation for the month is 4.63 in over about 9 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
- 88°F
- Average low
- 65°F
- Precipitation
- 4.63 in
- Record high
- 113°FAug 14, 1936
- Record low
- 42°FAug 27, 1910
- Chance of a freeze
- 0%
- Days of 90°F or more
- 15.1
- Daylight
- 14 h 08 min to 13 h 02 min
- Cloud cover
- 46%
- Humidity
- 68%
- Dew point
- 65°F
- Wind
- 8.3 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 | 90°F | 67°F | 107°F 1934 | 51°F 1971 | 30% | 0% |
| Aug 2 | 90°F | 67°F | 107°F 1934 | 53°F 1925 | 30% | 0% |
| Aug 3 | 90°F | 67°F | 110°F 1918 | 52°F 1907 | 30% | 0% |
| Aug 4 | 90°F | 67°F | 109°F 1930 | 49°F 1974 | 30% | 0% |
| Aug 5 | 90°F | 67°F | 110°F 1934 | 52°F 1915 | 30% | 0% |
| Aug 6 | 90°F | 67°F | 109°F 1934 | 52°F 1948 | 30% | 0% |
| Aug 7 | 90°F | 67°F | 110°F 1934 | 50°F 1990 | 30% | 0% |
| Aug 8 | 90°F | 67°F | 110°F 1934 | 51°F 1989 | 30% | 0% |
| Aug 9 | 90°F | 67°F | 112°F 1936 | 54°F 1922 | 30% | 0% |
| Aug 10 | 89°F | 66°F | 112°F 1934 | 51°F 1917 | 30% | 0% |
| Aug 11 | 89°F | 66°F | 111°F 1934 | 45°F 1902 | 30% | 0% |
| Aug 12 | 89°F | 66°F | 109°F 1936 | 48°F 1931 | 30% | 0% |
| Aug 13 | 89°F | 66°F | 111°F 1936 | 51°F 1931 | 30% | 0% |
| Aug 14 | 89°F | 66°F | 113°F 1936 | 54°F 1920 | 29% | 0% |
| Aug 15 | 89°F | 66°F | 111°F 1936 | 49°F 1929 | 29% | 0% |
| Aug 16 | 89°F | 65°F | 111°F 1936 | 52°F 1897 | 29% | 0% |
| Aug 17 | 88°F | 65°F | 109°F 1936 | 52°F 1943 | 29% | 0% |
| Aug 18 | 88°F | 65°F | 108°F 1934 | 46°F 1943 | 29% | 0% |
| Aug 19 | 88°F | 65°F | 109°F 1936 | 50°F 1943 | 29% | 0% |
| Aug 20 | 88°F | 65°F | 105°F 2023 | 47°F 1967 | 29% | 0% |
| Aug 21 | 88°F | 64°F | 107°F 2003 | 45°F 1950 | 29% | 0% |
| Aug 22 | 87°F | 64°F | 106°F 1936 | 50°F 1920 | 29% | 0% |
| Aug 23 | 87°F | 64°F | 108°F 1936 | 44°F 1904 | 28% | 0% |
| Aug 24 | 87°F | 64°F | 110°F 1936 | 50°F 1896 | 28% | 0% |
| Aug 25 | 87°F | 63°F | 107°F 1901 | 46°F 1958 | 28% | 0% |
| Aug 26 | 86°F | 63°F | 106°F 1936 | 43°F 1910 | 28% | 0% |
| Aug 27 | 86°F | 63°F | 109°F 2000 | 42°F 1910 | 28% | 0% |
| Aug 28 | 86°F | 62°F | 108°F 1984 | 45°F 1916 | 28% | 0% |
| Aug 29 | 86°F | 62°F | 108°F 1984 | 45°F 1988 | 28% | 0% |
| Aug 30 | 85°F | 62°F | 108°F 1947 | 44°F 1909 | 28% | 0% |
| Aug 31 | 85°F | 62°F | 108°F 1947 | 43°F 1915 | 28% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- August 1
- sunrise 6:23 AM, sunset 8:31 PM
- August 31
- sunrise 6:50 AM, sunset 7:52 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00146128 (Ottawa), public domain. Records: NOAA GHCN-Daily, station USC00146128, 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.