August is one of the warmer months of the year in Mississauga, with average highs near 23.6°C and lows around 17.1°C (mean 20.4°C). It is about average for rainfall, averaging 60 mm of rainfall and 73% relative humidity across the period.
August is one of the warmer months of the year in Mississauga. Across 45 years of records, the warmest August in Mississauga was 2021 — when the month averaged 24.5°C — while the coldest was 1992 at 15.5°C. Typical August days reach 23.6°C with nights near 17.1°C. The long-term trend is warming, about 1.3°C per decade.
August is about average for rainfall in Mississauga, averaging 60 mm of rainfall. The wettest August on record was 1992 with 117 mm, while the driest were 1996 and 2002 at 27 mm.
Relative humidity in Mississauga during August averages 73%. The most humid August was 1992 at 80%, and the least humid was 2025 at 66%.
August receives about 5.2 kWh/m²/day of solar energy in Mississauga. The sunniest Augusts were 2002 and 2016 at 5.8 kWh/m²/day, and the cloudiest was 1997 at 4.6.
Average wind speed in Mississauga during August is 3.1 m/s. The windiest August was 2017 at 3.5 m/s, while the calmest were 1993, 1996 and 2003 at 2.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 18.4°C | 18.5°C | 20.8°C | 22.2°C | 22.8°C | +4.4°C |
| Avg High | 21.9°C | 22.0°C | 23.9°C | 25.1°C | 25.7°C | +3.8°C |
| Avg Low | 14.8°C | 14.9°C | 17.7°C | 19.3°C | 19.8°C | +5°C |
| Avg Rain | 68 mm | 59 mm | 61 mm | 58 mm | 51 mm | -17 mm |
August temperatures in Mississauga have risen by about 3.9°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 6.8°C (1982) to a record high of 31.9°C (2006).
Rainfall in August is about average for rainfall, averaging 60 mm, with a wettest year of 117 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 1.1°C per decade while lows rose 1.6°C per decade, narrowing the gap between day and night.
One of the best times to visit Mississauga
August is one of the best times to visit Mississauga. Expect days averaging 23.6°C and nights around 17.1°C (mean 20.4°C) — warmer than Mississauga's yearly average — with moderate rainfall (60 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 25.6°C | 22.7°C | 19.9°C | 30.4°C | 13.8°C | 43 mm | 66% | 3.4 m/s | 5.3 |
| 2024 | 25.5°C | 22.6°C | 19.7°C | 29.4°C | 15.1°C | 56 mm | 71% | 3.2 m/s | 4.8 |
| 2023 | 24.2°C | 21.1°C | 18.1°C | 26.8°C | 15.3°C | 64 mm | 72% | 3.4 m/s | 5 |
| 2022 | 25.9°C | 22.8°C | 19.8°C | 28.5°C | 16.6°C | 52 mm | 70% | 2.9 m/s | 5.3 |
| 2021 🔥 | 27.4°C | 24.5°C | 21.7°C | 30.7°C | 16.6°C | 33 mm | 71% | 3 m/s | 5.3 |
| 2020 | 25.9°C | 22.9°C | 19.9°C | 29.2°C | 17.5°C | 58 mm | 71% | 3.4 m/s | 5.6 |
| 2019 | 24.9°C | 22.0°C | 19.1°C | 29.0°C | 15.5°C | 61 mm | 71% | 3.2 m/s | 5.7 |
| 2018 | 26.4°C | 23.9°C | 21.3°C | 29.9°C | 17.9°C | 81 mm | 75% | 3.4 m/s | 4.9 |
| 2017 | 23.9°C | 21.0°C | 18.1°C | 27.6°C | 14.5°C | 52 mm | 73% | 3.5 m/s | 5.1 |
| 2016 | 27.3°C | 24.2°C | 21.1°C | 31.8°C | 17.0°C | 62 mm | 71% | 3 m/s | 5.8 |
| 2015 | 23.9°C | 21.0°C | 18.1°C | 27.6°C | 14.9°C | 54 mm | 73% | 3.1 m/s | 5.2 |
| 2014 | 23.4°C | 20.5°C | 17.6°C | 26.9°C | 14.1°C | 40 mm | 75% | 3.1 m/s | 5.1 |
| 2013 | 24.2°C | 21.2°C | 18.1°C | 27.6°C | 13.9°C | 64 mm | 73% | 3 m/s | 5.4 |
| 2012 | 25.8°C | 22.7°C | 19.6°C | 30.3°C | 16.2°C | 50 mm | 69% | 3.2 m/s | 5.4 |
| 2011 | 25.3°C | 22.5°C | 19.6°C | 29.5°C | 16.5°C | 66 mm | 71% | 3.1 m/s | 5.1 |
| 2010 | 25.7°C | 22.8°C | 19.9°C | 29.8°C | 15.7°C | 55 mm | 73% | 3.4 m/s | 5.1 |
| 2009 | 24.1°C | 21.4°C | 18.6°C | 28.9°C | 15.3°C | 113 mm | 75% | 3.2 m/s | 5.2 |
| 2008 | 23.5°C | 20.6°C | 17.7°C | 26.4°C | 14.6°C | 79 mm | 74% | 3.1 m/s | 5.5 |
| 2007 | 25.2°C | 22.2°C | 19.2°C | 30.0°C | 14.5°C | 33 mm | 70% | 3.3 m/s | 5.2 |
| 2006 | 24.8°C | 21.9°C | 19.0°C | 31.9°C | 15.6°C | 51 mm | 70% | 3.4 m/s | 5.4 |
| 2005 | 26.3°C | 23.1°C | 20.0°C | 30.7°C | 16.4°C | 84 mm | 70% | 3.2 m/s | 5.1 |
| 2004 | 23.0°C | 20.4°C | 17.7°C | 26.1°C | 15.2°C | 54 mm | 73% | 3.4 m/s | 4.7 |
| 2003 | 22.4°C | 19.0°C | 15.5°C | 28.0°C | 12.3°C | 48 mm | 77% | 2.4 m/s | 5.3 |
| 2002 | 22.8°C | 19.0°C | 15.3°C | 26.6°C | 11.2°C | 27 mm | 72% | 2.8 m/s | 5.8 |
| 2001 | 23.0°C | 19.2°C | 15.4°C | 29.0°C | 12.6°C | 50 mm | 73% | 2.8 m/s | 5.4 |
| 2000 | 24.0°C | 21.2°C | 18.4°C | 27.5°C | 13.6°C | 76 mm | 74% | 3.4 m/s | 5.1 |
| 1999 | 21.0°C | 17.6°C | 14.1°C | 25.0°C | 10.9°C | 53 mm | 73% | 3 m/s | 4.9 |
| 1998 | 25.5°C | 22.7°C | 19.8°C | 28.9°C | 15.4°C | 40 mm | 69% | 2.9 m/s | 5.3 |
| 1997 | 23.1°C | 20.1°C | 17.1°C | 27.2°C | 14.4°C | 58 mm | 71% | 3.3 m/s | 4.6 |
| 1996 | 22.2°C | 18.1°C | 14.1°C | 25.8°C | 11.3°C | 27 mm | 75% | 2.4 m/s | 5.6 |
| 1995 | 23.1°C | 19.5°C | 15.9°C | 28.7°C | 10.6°C | 46 mm | 75% | 2.8 m/s | 5.1 |
| 1994 | 20.4°C | 16.7°C | 12.9°C | 25.2°C | 9.2°C | 55 mm | 77% | 2.8 m/s | 5.2 |
| 1993 | 22.6°C | 18.8°C | 15.0°C | 28.4°C | 10.6°C | 44 mm | 73% | 2.4 m/s | 5.6 |
| 1992 ❄️ 🌧️ | 19.1°C | 15.5°C | 11.9°C | 24.4°C | 9.0°C | 117 mm | 80% | 3.1 m/s | 5.1 |
| 1991 | 21.5°C | 17.7°C | 13.9°C | 26.4°C | 11.1°C | 65 mm | 75% | 3 m/s | 5.3 |
| 1990 | 21.6°C | 17.9°C | 14.2°C | 25.8°C | 11.9°C | 86 mm | 77% | 2.5 m/s | 5 |
| 1989 | 21.3°C | 17.4°C | 13.6°C | 25.5°C | 9.3°C | 34 mm | 75% | 2.9 m/s | 5 |
| 1988 | 22.3°C | 18.7°C | 15.0°C | 27.0°C | 10.5°C | 52 mm | 74% | 3.1 m/s | 5.2 |
| 1987 | 21.4°C | 17.9°C | 14.4°C | 28.2°C | 9.7°C | 47 mm | 72% | 3.4 m/s | 4.9 |
| 1986 | 20.9°C | 17.5°C | 14.1°C | 27.2°C | 8.3°C | 86 mm | 75% | 3.2 m/s | 5.1 |
| 1985 | 21.6°C | 18.1°C | 14.6°C | 26.8°C | 10.6°C | 92 mm | 73% | 2.9 m/s | 5 |
| 1984 | 23.5°C | 19.8°C | 16.0°C | 28.0°C | 12.1°C | 45 mm | 74% | 2.8 m/s | 5.4 |
| 1983 | 23.2°C | 19.6°C | 16.1°C | 28.2°C | 12.4°C | 90 mm | 74% | 2.7 m/s | — |
| 1982 | 20.7°C | 17.1°C | 13.4°C | 26.5°C | 6.8°C | 86 mm | 72% | 3.1 m/s | — |
| 1981 | 22.5°C | 19.4°C | 16.3°C | 25.1°C | 11.8°C | 81 mm | 76% | 2.9 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 23.6°C with lows near 17.1°C (mean 20.4°C), based on 45 years of NASA POWER data.
August averages 60 mm of rainfall in Mississauga, about average for rainfall. The wettest on record was 117 mm in 1992.
The hottest August reached 31.9°C in 2006. The coldest dipped to 6.8°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 3.9°C. Daytime highs moved from 22.3°C to 25.7°C and overnight lows from 15.3°C to 19.8°C over the same span.
August is one of the warmer months of the year in Mississauga and about average for rainfall, so plan for around 23.6°C daytime highs and 17.1°C at night.
Not quite — August is the 11th coolest month in Mississauga, averaging 20.4°C.
For August in Mississauga, pack light layers you can adjust through the day, with typical highs of 23.6°C and lows of 17.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 73% — moderately humid.
Average wind speed in August is 3.1 m/s. The windiest August on record averaged 3.5 m/s (2017).
The wettest August on record was 1992 with 117 mm. On average, August sees 60 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Mississauga behaves each August, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for August specifically, along with year-by-year records and how the month has changed over the decades.
