Ontario Weather in August
Average highs run from 95°F on August 1 to 87°F on August 31, and lows from 61°F to 53°F. Normal precipitation for the month is 0.10 in over about 1 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
- 91°F
- Average low
- 57°F
- Precipitation
- 0.10 in
- Record high
- 109°FAug 1, 2022
- Record low
- 39°FAug 31, 1999
- Chance of a freeze
- 0%
- Days of 90°F or more
- 21.7
- Daylight
- 14 h 36 min to 13 h 15 min
- Cloud cover
- 30%
- Humidity
- 32%
- Dew point
- 41°F
- Wind
- 6.3 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 | 95°F | 61°F | 109°F 2022 | 47°F 2001 | 6% | 0% |
| Aug 2 | 95°F | 61°F | 109°F 2024 | 53°F 2013 | 6% | 0% |
| Aug 3 | 95°F | 60°F | 103°F 2024 | 52°F 2002 | 6% | 0% |
| Aug 4 | 95°F | 60°F | 103°F 2019 | 53°F 1999 | 6% | 0% |
| Aug 5 | 95°F | 60°F | 105°F 1998 | 50°F 2026 | 6% | 0% |
| Aug 6 | 94°F | 60°F | 104°F 2005 | 53°F 2007 | 5% | 0% |
| Aug 7 | 94°F | 60°F | 104°F 2012 | 54°F 2007 | 5% | 0% |
| Aug 8 | 94°F | 59°F | 104°F 2022 | 48°F 1999 | 5% | 0% |
| Aug 9 | 94°F | 59°F | 105°F 2018 | 47°F 2002 | 5% | 0% |
| Aug 10 | 93°F | 59°F | 105°F 2018 | 48°F 2002 | 5% | 0% |
| Aug 11 | 93°F | 59°F | 102°F 2015 | 52°F 2007 | 5% | 0% |
| Aug 12 | 93°F | 58°F | 106°F 2021 | 48°F 2010 | 5% | 0% |
| Aug 13 | 93°F | 58°F | 104°F 2015 | 51°F 2006 | 5% | 0% |
| Aug 14 | 92°F | 58°F | 101°F 1998 | 47°F 2006 | 5% | 0% |
| Aug 15 | 92°F | 58°F | 104°F 2023 | 47°F 1999 | 5% | 0% |
| Aug 16 | 92°F | 57°F | 109°F 2023 | 46°F 1999 | 5% | 0% |
| Aug 17 | 91°F | 57°F | 103°F 2022 | 49°F 2006 | 5% | 0% |
| Aug 18 | 91°F | 57°F | 102°F 2020 | 50°F 1999 | 5% | 0% |
| Aug 19 | 91°F | 56°F | 99°F 2003 | 46°F 2002 | 5% | 0% |
| Aug 20 | 90°F | 56°F | 101°F 2019 | 48°F 2001 | 5% | 0% |
| Aug 21 | 90°F | 56°F | 101°F 2019 | 51°F 2007 | 5% | 0% |
| Aug 22 | 90°F | 55°F | 100°F 2022 | 46°F 2002 | 5% | 0% |
| Aug 23 | 89°F | 55°F | 99°F 2022 | 43°F 2008 | 5% | 0% |
| Aug 24 | 89°F | 55°F | 99°F 2022 | 43°F 2010 | 5% | 0% |
| Aug 25 | 89°F | 54°F | 99°F 2026 | 44°F 2012 | 5% | 0% |
| Aug 26 | 88°F | 54°F | 100°F 2011 | 46°F 2005 | 5% | 0% |
| Aug 27 | 88°F | 54°F | 99°F 2001 | 43°F 2008 | 5% | 0% |
| Aug 28 | 88°F | 54°F | 98°F 2005 | 45°F 2018 | 5% | 0% |
| Aug 29 | 88°F | 53°F | 100°F 2017 | 43°F 2018 | 6% | 0% |
| Aug 30 | 87°F | 53°F | 99°F 2007 | 43°F 2010 | 6% | 0% |
| Aug 31 | 87°F | 53°F | 102°F 2022 | 39°F 1999 | 6% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MDT).
- August 1
- sunrise 6:36 AM, sunset 9:12 PM
- August 31
- sunrise 7:10 AM, sunset 8:25 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00356294 (Ontario Ksrv), public domain. Records: NOAA GHCN-Daily, station USW00024162, 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.