Ontario Weather in August
Average highs run from 81°F on August 1 to 78°F on August 31, and lows from 62°F to 58°F. Normal precipitation for the month is 4.11 in over about 12 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
- 80°F
- Average low
- 61°F
- Precipitation
- 4.11 in
- Record high
- 102°FAug 31, 1993
- Record low
- 37°FAug 22, 1957
- Chance of a freeze
- 0%
- Days of 90°F or more
- 1.9
- Daylight
- 14 h 31 min to 13 h 14 min
- Cloud cover
- 69%
- Humidity
- 70%
- Dew point
- 58°F
- Wind
- 4.5 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 | 81°F | 62°F | 95°F 1955 | 43°F 1930 | 39% | 0% |
| Aug 2 | 81°F | 62°F | 96°F 2007 | 43°F 1959 | 39% | 0% |
| Aug 3 | 81°F | 62°F | 97°F 1988 | 43°F 1924 | 39% | 0% |
| Aug 4 | 81°F | 62°F | 98°F 1938 | 45°F 1953 | 39% | 0% |
| Aug 5 | 81°F | 62°F | 95°F 1947 | 43°F 1972 | 39% | 0% |
| Aug 6 | 81°F | 62°F | 97°F 1947 | 46°F 1964 | 39% | 0% |
| Aug 7 | 81°F | 62°F | 95°F 1965 | 46°F 1957 | 39% | 0% |
| Aug 8 | 81°F | 62°F | 95°F 1930 | 43°F 1929 | 39% | 0% |
| Aug 9 | 81°F | 61°F | 98°F 2001 | 47°F 1955 | 40% | 0% |
| Aug 10 | 81°F | 61°F | 96°F 2005 | 41°F 1983 | 40% | 0% |
| Aug 11 | 81°F | 61°F | 98°F 1944 | 45°F 1968 | 40% | 0% |
| Aug 12 | 80°F | 61°F | 99°F 1944 | 46°F 1987 | 40% | 0% |
| Aug 13 | 80°F | 61°F | 94°F 1947 | 42°F 1930 | 40% | 0% |
| Aug 14 | 80°F | 61°F | 100°F 2002 | 44°F 2008 | 40% | 0% |
| Aug 15 | 80°F | 61°F | 97°F 2002 | 45°F 1924 | 40% | 0% |
| Aug 16 | 80°F | 61°F | 93°F 1938 | 44°F 1923 | 40% | 0% |
| Aug 17 | 80°F | 61°F | 96°F 1944 | 41°F 1961 | 39% | 0% |
| Aug 18 | 80°F | 61°F | 91°F 1947 | 44°F 1962 | 39% | 0% |
| Aug 19 | 80°F | 60°F | 91°F 1978 | 45°F 1957 | 39% | 0% |
| Aug 20 | 80°F | 60°F | 92°F 1939 | 42°F 1929 | 39% | 0% |
| Aug 21 | 79°F | 60°F | 90°F 1945 | 42°F 1929 | 38% | 0% |
| Aug 22 | 79°F | 60°F | 91°F 1942 | 37°F 1957 | 38% | 0% |
| Aug 23 | 79°F | 60°F | 92°F 1943 | 42°F 1923 | 38% | 0% |
| Aug 24 | 79°F | 60°F | 93°F 1947 | 39°F 1923 | 38% | 0% |
| Aug 25 | 79°F | 60°F | 94°F 2007 | 39°F 1960 | 37% | 0% |
| Aug 26 | 79°F | 59°F | 93°F 1959 | 41°F 2008 | 37% | 0% |
| Aug 27 | 78°F | 59°F | 101°F 1953 | 43°F 1923 | 37% | 0% |
| Aug 28 | 78°F | 59°F | 93°F 1953 | 38°F 1957 | 37% | 0% |
| Aug 29 | 78°F | 59°F | 95°F 2007 | 40°F 1982 | 37% | 0% |
| Aug 30 | 78°F | 58°F | 95°F 1953 | 40°F 1965 | 36% | 0% |
| Aug 31 | 78°F | 58°F | 102°F 1993 | 40°F 1965 | 36% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (EDT).
- August 1
- sunrise 6:00 AM, sunset 8:31 PM
- August 31
- sunrise 6:32 AM, sunset 7:46 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00309049 (Webster 2 Ne), public domain. Records: NOAA GHCN-Daily, station USC00307842, 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.