Ottawa Weather in August
Average highs run from 26°C on August 1 to 24°C on August 31, and lows from 15°C to 13°C. Normal precipitation for the month is 84 mm over about 12 wet days.
August day by day
The normal high and low for each date, in °C.
- Normal low
- Normal high
- Reanalysis extreme high
- Reanalysis extreme low
August at a glance
- Average high
- 25°C
- Average low
- 14°C
- Precipitation
- 84 mm
- Reanalysis high
- 34°CAug 1, 2002
- Reanalysis low
- 6°CAug 24, 2004
- Daylight
- 14 h 43 min to 13 h 19 min
- Cloud cover
- 58%
- Humidity
- 78%
- Dew point
- 15°C
- Wind
- 6.1 km/h
Every day of the month
A wet day has at least 1 mm of precipitation in the reanalysis.
| Date | Normal high | Normal low | Reanalysis high | Reanalysis low | Chance wet |
|---|---|---|---|---|---|
| Aug 1 | 26°C | 15°C | 34°C 2002 | 11°C 1998 | 49% |
| Aug 2 | 26°C | 15°C | 32°C 2007 | 13°C 2015 | 49% |
| Aug 3 | 26°C | 15°C | 30°C 2016 | 11°C 2009 | 49% |
| Aug 4 | 26°C | 15°C | 34°C 2012 | 10°C 2013 | 48% |
| Aug 5 | 25°C | 15°C | 33°C 2001 | 8°C 2013 | 48% |
| Aug 6 | 25°C | 15°C | 31°C 2018 | 8°C 1997 | 47% |
| Aug 7 | 25°C | 15°C | 32°C 2001 | 8°C 2010 | 47% |
| Aug 8 | 25°C | 15°C | 33°C 2001 | 10°C 2004 | 48% |
| Aug 9 | 25°C | 15°C | 34°C 2001 | 10°C 1999 | 48% |
| Aug 10 | 25°C | 15°C | 34°C 2016 | 9°C 1994 | 47% |
| Aug 11 | 25°C | 15°C | 33°C 2016 | 8°C 1996 | 46% |
| Aug 12 | 25°C | 14°C | 30°C 2002 | 8°C 1992 | 45% |
| Aug 13 | 25°C | 14°C | 30°C 2009 | 8°C 1992 | 44% |
| Aug 14 | 25°C | 14°C | 31°C 2002 | 8°C 1992 | 46% |
| Aug 15 | 25°C | 14°C | 31°C 1995 | 8°C 2014 | 47% |
| Aug 16 | 25°C | 14°C | 30°C 2015 | 9°C 1994 | 47% |
| Aug 17 | 25°C | 14°C | 31°C 2015 | 9°C 2007 | 46% |
| Aug 18 | 25°C | 14°C | 30°C 2015 | 9°C 2014 | 44% |
| Aug 19 | 25°C | 14°C | 30°C 2015 | 7°C 2007 | 43% |
| Aug 20 | 25°C | 14°C | 31°C 2003 | 7°C 2007 | 42% |
| Aug 21 | 25°C | 14°C | 30°C 2013 | 8°C 2007 | 42% |
| Aug 22 | 25°C | 14°C | 29°C 2001 | 8°C 2004 | 42% |
| Aug 23 | 24°C | 13°C | 29°C 1999 | 7°C 1994 | 42% |
| Aug 24 | 24°C | 13°C | 30°C 1999 | 6°C 2004 | 42% |
| Aug 25 | 24°C | 13°C | 32°C 2012 | 8°C 2004 | 40% |
| Aug 26 | 24°C | 13°C | 31°C 2012 | 8°C 2017 | 41% |
| Aug 27 | 24°C | 13°C | 31°C 1991 | 7°C 2009 | 41% |
| Aug 28 | 24°C | 13°C | 31°C 1999 | 8°C 2009 | 41% |
| Aug 29 | 24°C | 13°C | 29°C 2007 | 9°C 2012 | 38% |
| Aug 30 | 24°C | 13°C | 31°C 2010 | 8°C 1996 | 37% |
| Aug 31 | 24°C | 13°C | 32°C 2010 | 7°C 2006 | 38% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (EDT).
- August 1
- sunrise 5:47 AM, sunset 8:30 PM
- August 31
- sunrise 6:23 AM, sunset 7:42 PM
Other months
Sources
Cloud, humidity, wind and sunshine, and temperature and precipitation: 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.