August is one of the warmer months of the year in Summerside, with average highs near 21.8°C and lows around 15.4°C (mean 18.6°C). It is about average for rainfall, averaging 82 mm of rainfall and 82% relative humidity across the period.
August is one of the warmer months of the year in Summerside. Across 45 years of records, the warmest August in Summerside was 2012 — when the month averaged 20.5°C — while the coldest was 1982 at 16.2°C. Typical August days reach 21.8°C with nights near 15.4°C. The long-term trend is warming, about 0.4°C per decade.
August is about average for rainfall in Summerside, averaging 82 mm of rainfall. The wettest August on record was 2009 with 168 mm, while the driest was 1993 at 19 mm.
Relative humidity in Summerside during August averages 82%. The most humid August was 2008 at 89%, and the least humid was 1995 at 73%.
August receives about 5 kWh/m²/day of solar energy in Summerside. The sunniest August was 2025 at 5.9 kWh/m²/day, and the cloudiest was 1988 at 4.1.
Average wind speed in Summerside during August is 3.4 m/s. The windiest August was 1989 at 4.2 m/s, while the calmest was 1996 at 2.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 17.8°C | 18.6°C | 18.3°C | 19.3°C | 19.5°C | +1.7°C |
| Avg High | 20.9°C | 22.1°C | 21.4°C | 22.4°C | 22.7°C | +1.8°C |
| Avg Low | 14.6°C | 15.1°C | 15.2°C | 16.2°C | 16.3°C | +1.7°C |
| Avg Rain | 93 mm | 60 mm | 92 mm | 85 mm | 79 mm | -14 mm |
August temperatures in Summerside have risen by about 1.8°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 8.1°C (1982) to a record high of 29.6°C (1995).
Rainfall in August is about average for rainfall, averaging 82 mm, with a wettest year of 168 mm.
One of the best times to visit Summerside
August is one of the best times to visit Summerside. Expect days averaging 21.8°C and nights around 15.4°C (mean 18.6°C) — warmer than Summerside's yearly average — with higher rainfall (82 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 | 22.6°C | 19.0°C | 15.5°C | 29.5°C | 13.2°C | 38 mm | 74% | 3.2 m/s | 5.9 |
| 2024 | 23.0°C | 19.9°C | 16.7°C | 26.1°C | 12.3°C | 73 mm | 83% | 3.2 m/s | 5.1 |
| 2023 | 21.1°C | 18.2°C | 15.3°C | 23.4°C | 12.6°C | 139 mm | 85% | 3.3 m/s | 4.4 |
| 2022 | 23.2°C | 20.3°C | 17.3°C | 27.5°C | 15.0°C | 98 mm | 84% | 3.3 m/s | 4.7 |
| 2021 | 23.6°C | 20.3°C | 17.0°C | 28.3°C | 13.4°C | 53 mm | 82% | 3.3 m/s | 5.3 |
| 2020 | 22.7°C | 19.5°C | 16.2°C | 27.0°C | 11.2°C | 75 mm | 80% | 3.8 m/s | 5.4 |
| 2019 | 22.7°C | 19.4°C | 16.1°C | 25.1°C | 12.5°C | 67 mm | 82% | 3.2 m/s | 5.3 |
| 2018 | 23.4°C | 20.3°C | 17.2°C | 27.7°C | 14.6°C | 98 mm | 84% | 3.3 m/s | 4.9 |
| 2017 | 21.7°C | 18.6°C | 15.5°C | 24.7°C | 12.8°C | 74 mm | 83% | 3.2 m/s | 5.1 |
| 2016 | 21.8°C | 18.7°C | 15.7°C | 24.2°C | 13.6°C | 129 mm | 83% | 3.6 m/s | 5 |
| 2015 | 23.4°C | 20.4°C | 17.4°C | 27.1°C | 14.3°C | 86 mm | 87% | 3.5 m/s | 5.3 |
| 2014 | 21.6°C | 18.8°C | 15.9°C | 25.2°C | 10.4°C | 79 mm | 82% | 3.5 m/s | 4.7 |
| 2013 | 21.9°C | 18.5°C | 15.1°C | 25.4°C | 12.0°C | 51 mm | 82% | 3.5 m/s | 5.3 |
| 2012 🔥 | 23.6°C | 20.5°C | 17.4°C | 26.0°C | 14.2°C | 73 mm | 83% | 3.1 m/s | 4.8 |
| 2011 | 21.5°C | 18.5°C | 15.6°C | 24.0°C | 12.8°C | 105 mm | 87% | 3.6 m/s | 4.8 |
| 2010 | 22.0°C | 18.9°C | 15.9°C | 25.7°C | 12.4°C | 86 mm | 82% | 2.9 m/s | 5.4 |
| 2009 🌧️ | 22.0°C | 19.1°C | 16.1°C | 26.7°C | 11.7°C | 168 mm | 85% | 3.3 m/s | 4.9 |
| 2008 | 20.4°C | 17.8°C | 15.2°C | 23.9°C | 12.6°C | 134 mm | 89% | 3.8 m/s | 4.2 |
| 2007 | 20.7°C | 17.7°C | 14.7°C | 25.6°C | 11.0°C | 115 mm | 83% | 3.2 m/s | 5.1 |
| 2006 | 19.8°C | 16.9°C | 13.9°C | 24.2°C | 10.7°C | 75 mm | 83% | 3.6 m/s | 5.1 |
| 2005 | 21.6°C | 18.4°C | 15.3°C | 24.9°C | 11.7°C | 49 mm | 84% | 3.3 m/s | 4.7 |
| 2004 | 22.1°C | 18.9°C | 15.7°C | 25.1°C | 12.1°C | 96 mm | 83% | 3.5 m/s | 4.8 |
| 2003 | 21.2°C | 18.2°C | 15.1°C | 24.4°C | 9.9°C | 95 mm | 85% | 3.3 m/s | 4.5 |
| 2002 | 22.1°C | 18.8°C | 15.5°C | 27.8°C | 11.2°C | 61 mm | 80% | 3.3 m/s | 5.2 |
| 2001 | 22.4°C | 19.0°C | 15.7°C | 26.3°C | 11.7°C | 24 mm | 81% | 3.3 m/s | 5.2 |
| 2000 | 21.4°C | 18.3°C | 15.2°C | 24.1°C | 12.7°C | 100 mm | 84% | 3.2 m/s | 4.7 |
| 1999 | 22.0°C | 18.7°C | 15.4°C | 26.3°C | 13.0°C | 111 mm | 78% | 3.6 m/s | 4.8 |
| 1998 | 22.7°C | 19.0°C | 15.3°C | 28.2°C | 11.6°C | 62 mm | 75% | 3.5 m/s | 5.1 |
| 1997 | 20.8°C | 17.6°C | 14.4°C | 25.0°C | 11.9°C | 25 mm | 79% | 3.2 m/s | 4.7 |
| 1996 | 22.2°C | 18.6°C | 15.0°C | 27.9°C | 13.0°C | 30 mm | 80% | 2.8 m/s | 5.2 |
| 1995 | 22.0°C | 18.4°C | 14.9°C | 29.6°C | 11.0°C | 41 mm | 73% | 4 m/s | 5 |
| 1994 | 22.0°C | 18.4°C | 14.9°C | 26.4°C | 12.0°C | 28 mm | 75% | 3.7 m/s | 5.2 |
| 1993 | 22.8°C | 19.0°C | 15.3°C | 26.5°C | 12.2°C | 19 mm | 76% | 3.1 m/s | 5.2 |
| 1992 | 21.8°C | 18.2°C | 14.6°C | 26.3°C | 11.9°C | 56 mm | 81% | 3.5 m/s | 5 |
| 1991 | 21.3°C | 18.1°C | 14.9°C | 25.3°C | 10.8°C | 110 mm | 83% | 3.8 m/s | 4.5 |
| 1990 | 23.0°C | 19.6°C | 16.3°C | 26.5°C | 12.2°C | 114 mm | 84% | 3.4 m/s | 5.1 |
| 1989 | 21.3°C | 18.2°C | 15.0°C | 25.2°C | 8.9°C | 71 mm | 83% | 4.2 m/s | 4.4 |
| 1988 | 21.6°C | 18.6°C | 15.7°C | 26.3°C | 11.4°C | 126 mm | 84% | 3.3 m/s | 4.1 |
| 1987 | 21.2°C | 17.7°C | 14.2°C | 28.2°C | 10.1°C | 54 mm | 78% | 3.1 m/s | 5.1 |
| 1986 | 20.0°C | 16.9°C | 13.9°C | 23.9°C | 8.3°C | 87 mm | 84% | 3.3 m/s | 4.5 |
| 1985 | 20.8°C | 17.7°C | 14.6°C | 24.8°C | 11.9°C | 82 mm | 83% | 3 m/s | 4.9 |
| 1984 | 22.6°C | 19.4°C | 16.2°C | 26.3°C | 11.7°C | 129 mm | 86% | 3 m/s | 5.3 |
| 1983 | 20.5°C | 17.4°C | 14.4°C | 24.2°C | 11.5°C | 108 mm | 85% | 3.5 m/s | — |
| 1982 ❄️ | 19.3°C | 16.2°C | 13.2°C | 24.3°C | 8.1°C | 103 mm | 83% | 3.6 m/s | — |
| 1981 | 21.1°C | 17.8°C | 14.6°C | 25.0°C | 10.5°C | 82 mm | 85% | 3.6 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 21.8°C with lows near 15.4°C (mean 18.6°C), based on 45 years of NASA POWER data.
August averages 82 mm of rainfall in Summerside, about average for rainfall. The wettest on record was 168 mm in 2009.
The hottest August reached 29.6°C in 1995. The coldest dipped to 8.1°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1.8°C. Daytime highs moved from 20.9°C to 22.7°C and overnight lows from 14.6°C to 16.4°C over the same span.
August is one of the warmer months of the year in Summerside and about average for rainfall, so plan for around 21.8°C daytime highs and 15.4°C at night.
Not quite — August is the 12th coolest month in Summerside, averaging 18.6°C.
For August in Summerside, pack light layers you can adjust through the day, with typical highs of 21.8°C and lows of 15.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 82% — quite humid.
Average wind speed in August is 3.4 m/s. The windiest August on record averaged 4.2 m/s (1989).
The wettest August on record was 2009 with 168 mm. On average, August sees 82 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 Summerside 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.
