August is one of the warmer months of the year in Saint-Jean-sur-Richelieu, with average highs near 25.1°C and lows around 14.6°C (mean 19.9°C). It is a relatively wet time of year, averaging 102 mm of rainfall and 77% relative humidity across the period.
August is one of the warmer months of the year in Saint-Jean-sur-Richelieu. Across 45 years of records, the warmest August in Saint-Jean-sur-Richelieu was 2021 — when the month averaged 23.8°C — while the coldest was 1982 at 16.9°C. Typical August days reach 25.1°C with nights near 14.6°C. The long-term trend is warming, about 0.5°C per decade.
August is a relatively wet time of year in Saint-Jean-sur-Richelieu, averaging 102 mm of rainfall. The wettest August on record was 2006 with 166 mm, while the driest was 2002 at 38 mm.
Relative humidity in Saint-Jean-sur-Richelieu during August averages 77%. The most humid Augusts were 2004 and 2008 at 83%, and the least humid was 2025 at 65%.
August receives about 5 kWh/m²/day of solar energy in Saint-Jean-sur-Richelieu. The sunniest August was 2002 at 5.6 kWh/m²/day, and the cloudiest was 1988 at 4.4.
Average wind speed in Saint-Jean-sur-Richelieu during August is 2.1 m/s. The windiest Augusts were 1982, 1986 and 1992 at 2.3 m/s, while the calmest were 2008 and 2014 at 1.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 18.9°C | 19.4°C | 19.8°C | 20.5°C | 21.0°C | +2.1°C |
| Avg High | 24.3°C | 24.8°C | 24.8°C | 25.6°C | 26.4°C | +2.1°C |
| Avg Low | 13.5°C | 14.1°C | 14.7°C | 15.3°C | 15.7°C | +2.2°C |
| Avg Rain | 109 mm | 95 mm | 107 mm | 99 mm | 101 mm | -7 mm |
August temperatures in Saint-Jean-sur-Richelieu have risen by about 2.2°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 4°C (1982) to a record high of 35.3°C (2025).
Rainfall in August is a relatively wet time of year, averaging 102 mm, with a wettest year of 166 mm.
One of the best times to visit Saint-Jean-sur-Richelieu
August is one of the best times to visit Saint-Jean-sur-Richelieu. Expect days averaging 25.1°C and nights around 14.6°C (mean 19.9°C) — warmer than Saint-Jean-sur-Richelieu's yearly average — with higher rainfall (102 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 | 27.1°C | 21.0°C | 14.9°C | 35.3°C | 8.8°C | 73 mm | 65% | 2 m/s | 5.4 |
| 2024 | 25.3°C | 20.3°C | 15.3°C | 31.9°C | 8.6°C | 155 mm | 80% | 2 m/s | 4.5 |
| 2023 | 23.8°C | 19.0°C | 14.3°C | 27.0°C | 8.6°C | 108 mm | 81% | 2 m/s | 4.6 |
| 2022 | 27.0°C | 21.4°C | 15.9°C | 33.6°C | 11.3°C | 101 mm | 73% | 2 m/s | 4.9 |
| 2021 🔥 | 29.5°C | 23.8°C | 18.1°C | 34.9°C | 12.2°C | 40 mm | 69% | 2.2 m/s | 4.9 |
| 2020 | 25.4°C | 20.5°C | 15.6°C | 31.9°C | 9.3°C | 131 mm | 76% | 2.2 m/s | 5.1 |
| 2019 | 25.7°C | 20.2°C | 14.7°C | 30.4°C | 10.3°C | 84 mm | 75% | 2.1 m/s | 5.4 |
| 2018 | 27.7°C | 22.4°C | 17.1°C | 32.6°C | 10.0°C | 69 mm | 76% | 2.1 m/s | 4.9 |
| 2017 | 23.8°C | 19.0°C | 14.3°C | 27.8°C | 9.2°C | 85 mm | 80% | 2 m/s | 5.3 |
| 2016 | 26.9°C | 21.8°C | 16.7°C | 32.2°C | 11.0°C | 136 mm | 76% | 2.2 m/s | 5.1 |
| 2015 | 25.4°C | 20.4°C | 15.4°C | 30.7°C | 10.7°C | 92 mm | 79% | 2 m/s | 5 |
| 2014 | 24.3°C | 19.5°C | 14.7°C | 28.7°C | 10.3°C | 84 mm | 79% | 1.8 m/s | 5.1 |
| 2013 | 24.9°C | 19.6°C | 14.3°C | 29.9°C | 9.5°C | 82 mm | 77% | 2.2 m/s | 5.2 |
| 2012 | 27.2°C | 21.7°C | 16.2°C | 32.2°C | 9.3°C | 80 mm | 72% | 2.1 m/s | 5.1 |
| 2011 | 24.7°C | 20.0°C | 15.2°C | 29.0°C | 10.2°C | 161 mm | 81% | 2.1 m/s | 4.8 |
| 2010 | 25.2°C | 20.0°C | 14.8°C | 32.9°C | 9.4°C | 114 mm | 80% | 2.1 m/s | 5.1 |
| 2009 | 24.6°C | 19.9°C | 15.3°C | 30.7°C | 7.7°C | 74 mm | 82% | 2 m/s | 5 |
| 2008 | 23.3°C | 18.8°C | 14.3°C | 27.7°C | 9.0°C | 125 mm | 83% | 1.8 m/s | 5 |
| 2007 | 24.5°C | 19.0°C | 13.4°C | 31.4°C | 7.4°C | 100 mm | 79% | 2.1 m/s | 5.2 |
| 2006 🌧️ | 23.0°C | 18.3°C | 13.6°C | 31.0°C | 7.3°C | 166 mm | 81% | 2.1 m/s | 5.2 |
| 2005 | 26.0°C | 20.8°C | 15.6°C | 30.7°C | 9.6°C | 127 mm | 78% | 2 m/s | 5 |
| 2004 | 23.6°C | 18.7°C | 13.9°C | 28.1°C | 7.1°C | 127 mm | 83% | 2 m/s | 4.6 |
| 2003 | 25.7°C | 20.9°C | 16.1°C | 30.2°C | 8.7°C | 88 mm | 79% | 2.1 m/s | 4.6 |
| 2002 | 26.1°C | 20.7°C | 15.3°C | 32.4°C | 9.1°C | 38 mm | 77% | 2 m/s | 5.6 |
| 2001 | 27.4°C | 21.7°C | 16.0°C | 33.1°C | 9.4°C | 105 mm | 72% | 2.2 m/s | 5.3 |
| 2000 | 23.8°C | 18.8°C | 13.7°C | 28.8°C | 8.3°C | 123 mm | 83% | 2.2 m/s | 4.7 |
| 1999 | 24.7°C | 19.4°C | 14.1°C | 29.8°C | 8.6°C | 80 mm | 73% | 2 m/s | 5.1 |
| 1998 | 25.2°C | 20.2°C | 15.3°C | 31.1°C | 9.2°C | 105 mm | 77% | 1.9 m/s | 5.1 |
| 1997 | 24.1°C | 18.8°C | 13.5°C | 31.7°C | 9.3°C | 90 mm | 75% | 2 m/s | 5 |
| 1996 | 25.0°C | 19.5°C | 14.0°C | 30.2°C | 8.6°C | 51 mm | 78% | 1.9 m/s | 5.3 |
| 1995 | 25.9°C | 19.9°C | 14.0°C | 31.4°C | 8.0°C | 93 mm | 73% | 2.2 m/s | 5.3 |
| 1994 | 23.4°C | 18.0°C | 12.7°C | 28.7°C | 7.2°C | 83 mm | 80% | 2.2 m/s | 5 |
| 1993 | 25.4°C | 20.2°C | 15.1°C | 30.1°C | 9.7°C | 75 mm | 81% | 1.9 m/s | 5.2 |
| 1992 | 23.5°C | 18.3°C | 13.0°C | 30.0°C | 8.1°C | 106 mm | 80% | 2.3 m/s | 4.7 |
| 1991 | 25.7°C | 20.4°C | 15.1°C | 31.0°C | 7.9°C | 137 mm | 77% | 2.2 m/s | 4.9 |
| 1990 | 25.0°C | 19.6°C | 14.2°C | 29.1°C | 7.7°C | 125 mm | 81% | 1.9 m/s | 5.2 |
| 1989 | 23.9°C | 18.7°C | 13.4°C | 30.0°C | 5.2°C | 121 mm | 77% | 2.1 m/s | 5.1 |
| 1988 | 25.5°C | 20.3°C | 15.2°C | 33.1°C | 7.6°C | 149 mm | 78% | 2.2 m/s | 4.4 |
| 1987 | 24.7°C | 18.6°C | 12.6°C | 33.2°C | 6.4°C | 57 mm | 71% | 2.2 m/s | 5 |
| 1986 | 23.0°C | 17.7°C | 12.4°C | 28.0°C | 4.4°C | 133 mm | 80% | 2.3 m/s | 4.8 |
| 1985 | 24.1°C | 18.4°C | 12.8°C | 29.5°C | 5.9°C | 68 mm | 75% | 2.1 m/s | 4.7 |
| 1984 | 26.0°C | 20.9°C | 15.7°C | 30.5°C | 8.7°C | 98 mm | 78% | 2 m/s | 5.4 |
| 1983 | 25.2°C | 19.9°C | 14.6°C | 29.1°C | 7.9°C | 89 mm | 76% | 1.9 m/s | — |
| 1982 ❄️ | 22.4°C | 16.9°C | 11.4°C | 28.1°C | 4.0°C | 130 mm | 76% | 2.3 m/s | — |
| 1981 | 23.7°C | 18.5°C | 13.3°C | 28.8°C | 7.6°C | 132 mm | 80% | 1.9 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 25.1°C with lows near 14.6°C (mean 19.9°C), based on 45 years of NASA POWER data.
August averages 102 mm of rainfall in Saint-Jean-sur-Richelieu, a relatively wet time of year. The wettest on record was 166 mm in 2006.
The hottest August reached 35.3°C in 2025. The coldest dipped to 4°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 2.2°C. Daytime highs moved from 24.3°C to 26.5°C and overnight lows from 13.6°C to 15.7°C over the same span.
August is one of the warmer months of the year in Saint-Jean-sur-Richelieu and a relatively wet time of year, so plan for around 25.1°C daytime highs and 14.6°C at night.
Not quite — August is the 11th coolest month in Saint-Jean-sur-Richelieu, averaging 19.9°C.
For August in Saint-Jean-sur-Richelieu, pack light layers you can adjust through the day, with typical highs of 25.1°C and lows of 14.6°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 77% — quite humid.
Average wind speed in August is 2.1 m/s. The windiest August on record averaged 2.3 m/s (1982).
The wettest August on record was 2006 with 166 mm. On average, August sees 102 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 Saint-Jean-sur-Richelieu 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.
