August is one of the warmer months of the year in Moncton, with average highs near 23.5°C and lows around 13.1°C (mean 18.3°C). It is about average for rainfall, averaging 81 mm of rainfall and 83% relative humidity across the period.
August is one of the warmer months of the year in Moncton. Across 45 years of records, the warmest August in Moncton was 2015 — when the month averaged 20.3°C — while the coldest was 1982 at 15.6°C. Typical August days reach 23.5°C with nights near 13.1°C. The long-term trend is warming, about 0.4°C per decade.
August is about average for rainfall in Moncton, averaging 81 mm of rainfall. The wettest August on record was 2009 with 168 mm, while the driest was 1993 at 22 mm.
Relative humidity in Moncton during August averages 83%. The most humid August was 2008 at 88%, and the least humid was 2025 at 73%.
August receives about 4.9 kWh/m²/day of solar energy in Moncton. The sunniest August was 2025 at 5.6 kWh/m²/day, and the cloudiest were 1988 and 2008 at 4.1.
Average wind speed in Moncton during August is 0.1 m/s. The windiest Augusts were 2023, 2024 and 2025, among others at 0.1 m/s, while the calmest were 2023, 2024 and 2025, among others at 0.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 17.5°C | 18.1°C | 18.1°C | 18.8°C | 19.2°C | +1.7°C |
| Avg High | 22.6°C | 23.4°C | 23.2°C | 23.9°C | 24.6°C | +2°C |
| Avg Low | 12.5°C | 12.8°C | 12.9°C | 13.7°C | 13.8°C | +1.3°C |
| Avg Rain | 94 mm | 71 mm | 88 mm | 77 mm | 75 mm | -20 mm |
August temperatures in Moncton have risen by about 1.7°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 4.9°C (1982) to a record high of 35.1°C (2025).
Rainfall in August is about average for rainfall, averaging 81 mm, with a wettest year of 168 mm.
One of the best times to visit Moncton
August is one of the best times to visit Moncton. Expect days averaging 23.5°C and nights around 13.1°C (mean 18.3°C) — warmer than Moncton's yearly average — with higher rainfall (81 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 | 25.7°C | 19.1°C | 12.5°C | 35.1°C | 7.4°C | 24 mm | 73% | 0.1 m/s | 5.6 |
| 2024 | 24.4°C | 19.2°C | 14.0°C | 29.3°C | 7.0°C | 65 mm | 84% | 0.1 m/s | 5 |
| 2023 | 22.6°C | 17.9°C | 13.1°C | 25.2°C | 7.8°C | 118 mm | 86% | 0.1 m/s | 4.2 |
| 2022 | 24.9°C | 20.0°C | 15.0°C | 30.9°C | 10.8°C | 118 mm | 84% | 0.1 m/s | 4.5 |
| 2021 | 25.6°C | 20.0°C | 14.5°C | 31.8°C | 10.1°C | 71 mm | 82% | 0.1 m/s | 5.1 |
| 2020 | 24.3°C | 19.1°C | 13.9°C | 30.0°C | 8.0°C | 53 mm | 80% | 0.1 m/s | 5.4 |
| 2019 | 23.9°C | 18.5°C | 13.1°C | 27.3°C | 8.2°C | 78 mm | 83% | 0.1 m/s | 5.1 |
| 2018 | 25.2°C | 20.1°C | 15.0°C | 29.9°C | 9.6°C | 80 mm | 85% | 0.1 m/s | 4.8 |
| 2017 | 23.3°C | 17.9°C | 12.5°C | 27.5°C | 8.2°C | 51 mm | 83% | 0.1 m/s | 5.1 |
| 2016 | 23.6°C | 18.4°C | 13.1°C | 26.3°C | 10.0°C | 100 mm | 84% | 0.1 m/s | 4.8 |
| 2015 🔥 | 25.0°C | 20.3°C | 15.6°C | 29.6°C | 12.4°C | 64 mm | 86% | 0.1 m/s | 5.1 |
| 2014 | 23.0°C | 18.0°C | 13.0°C | 27.5°C | 7.2°C | 87 mm | 84% | 0.1 m/s | 4.6 |
| 2013 | 22.9°C | 17.8°C | 12.6°C | 27.2°C | 7.2°C | 57 mm | 84% | 0.1 m/s | 5.1 |
| 2012 | 25.6°C | 20.2°C | 14.9°C | 31.9°C | 9.9°C | 62 mm | 84% | 0.1 m/s | 4.8 |
| 2011 | 23.0°C | 18.4°C | 13.8°C | 26.2°C | 10.4°C | 135 mm | 86% | 0.1 m/s | 4.4 |
| 2010 | 23.7°C | 18.5°C | 13.3°C | 29.8°C | 9.7°C | 53 mm | 83% | 0.1 m/s | 5.2 |
| 2009 🌧️ | 23.8°C | 18.8°C | 13.7°C | 29.6°C | 6.2°C | 168 mm | 85% | 0.1 m/s | 4.9 |
| 2008 | 22.1°C | 17.5°C | 12.9°C | 27.0°C | 9.6°C | 109 mm | 88% | 0.1 m/s | 4.1 |
| 2007 | 23.0°C | 17.7°C | 12.4°C | 27.9°C | 7.0°C | 76 mm | 82% | 0.1 m/s | 5.2 |
| 2006 | 21.1°C | 16.2°C | 11.2°C | 26.9°C | 6.1°C | 75 mm | 84% | 0.1 m/s | 4.8 |
| 2005 | 23.3°C | 18.1°C | 12.8°C | 27.5°C | 6.8°C | 67 mm | 84% | 0.1 m/s | 4.7 |
| 2004 | 23.5°C | 18.4°C | 13.3°C | 27.6°C | 8.0°C | 102 mm | 84% | 0.1 m/s | 4.8 |
| 2003 | 23.6°C | 18.6°C | 13.6°C | 33.4°C | 6.5°C | 104 mm | 85% | 0.1 m/s | 4.4 |
| 2002 | 24.0°C | 18.6°C | 13.2°C | 31.3°C | 6.9°C | 56 mm | 82% | 0.1 m/s | 5.3 |
| 2001 | 24.5°C | 18.9°C | 13.3°C | 28.9°C | 5.5°C | 35 mm | 82% | 0.1 m/s | 5.2 |
| 2000 | 22.8°C | 17.8°C | 12.9°C | 26.7°C | 7.7°C | 86 mm | 85% | 0.1 m/s | 4.6 |
| 1999 | 22.9°C | 17.8°C | 12.8°C | 28.0°C | 8.0°C | 100 mm | 82% | 0.1 m/s | 4.8 |
| 1998 | 24.4°C | 18.6°C | 12.9°C | 33.7°C | 8.0°C | 94 mm | 80% | 0.1 m/s | 5 |
| 1997 | 22.3°C | 17.1°C | 11.9°C | 26.5°C | 8.5°C | 33 mm | 84% | 0.1 m/s | 4.8 |
| 1996 | 23.5°C | 18.0°C | 12.6°C | 30.7°C | 8.5°C | 31 mm | 83% | 0.1 m/s | 5.3 |
| 1995 | 23.4°C | 17.7°C | 11.9°C | 34.2°C | 7.6°C | 49 mm | 78% | 0.1 m/s | 5.4 |
| 1994 | 22.7°C | 17.5°C | 12.4°C | 27.4°C | 6.8°C | 38 mm | 81% | 0.1 m/s | 5 |
| 1993 | 23.8°C | 18.4°C | 12.9°C | 28.3°C | 8.0°C | 22 mm | 82% | 0.1 m/s | 5.3 |
| 1992 | 23.0°C | 17.8°C | 12.6°C | 28.2°C | 9.2°C | 82 mm | 84% | 0.1 m/s | 4.9 |
| 1991 | 23.4°C | 18.3°C | 13.2°C | 29.1°C | 8.5°C | 162 mm | 85% | 0.1 m/s | 4.8 |
| 1990 | 24.9°C | 19.7°C | 14.5°C | 29.3°C | 6.9°C | 100 mm | 84% | 0.1 m/s | 5.2 |
| 1989 | 22.7°C | 17.8°C | 12.9°C | 27.4°C | 6.0°C | 87 mm | 83% | 0.1 m/s | 4.7 |
| 1988 | 23.3°C | 18.5°C | 13.7°C | 29.6°C | 6.2°C | 133 mm | 86% | 0.1 m/s | 4.1 |
| 1987 | 22.7°C | 17.2°C | 11.7°C | 31.2°C | 6.4°C | 41 mm | 80% | 0.1 m/s | 4.9 |
| 1986 | 21.4°C | 16.7°C | 11.9°C | 27.5°C | 5.4°C | 113 mm | 85% | 0.1 m/s | 4.6 |
| 1985 | 22.3°C | 17.2°C | 12.0°C | 28.5°C | 6.3°C | 76 mm | 84% | 0.1 m/s | 5 |
| 1984 | 25.4°C | 20.0°C | 14.7°C | 34.5°C | 9.1°C | 76 mm | 84% | 0.1 m/s | 5.2 |
| 1983 | 22.5°C | 17.5°C | 12.6°C | 29.4°C | 6.7°C | 96 mm | 85% | 0.1 m/s | — |
| 1982 ❄️ | 20.3°C | 15.6°C | 11.0°C | 26.6°C | 4.9°C | 114 mm | 84% | 0.1 m/s | — |
| 1981 | 22.5°C | 17.3°C | 12.0°C | 27.7°C | 6.4°C | 115 mm | 85% | 0.1 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 23.5°C with lows near 13.1°C (mean 18.3°C), based on 45 years of NASA POWER data.
August averages 81 mm of rainfall in Moncton, about average for rainfall. The wettest on record was 168 mm in 2009.
The hottest August reached 35.1°C in 2025. The coldest dipped to 4.9°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1.7°C. Daytime highs moved from 22.6°C to 24.6°C and overnight lows from 12.5°C to 13.8°C over the same span.
August is one of the warmer months of the year in Moncton and about average for rainfall, so plan for around 23.5°C daytime highs and 13.1°C at night.
Not quite — August is the 11th coolest month in Moncton, averaging 18.3°C.
For August in Moncton, pack light layers you can adjust through the day, with typical highs of 23.5°C and lows of 13.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 83% — quite humid.
Average wind speed in August is 0.1 m/s. The windiest August on record averaged 0.1 m/s (1981).
The wettest August on record was 2009 with 168 mm. On average, August sees 81 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 Moncton 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.
