August is one of the warmer months of the year in Dorchester, with average highs near 18.7°C and lows around 15.3°C (mean 17°C). It is one of the drier months, averaging 61 mm of rainfall and 83% relative humidity across the period.
August is one of the warmer months of the year in Dorchester. Across 45 years of records, the warmest August in Dorchester was 2022 — when the month averaged 19.3°C — while the coldest was 1986 at 14.7°C. Typical August days reach 18.7°C with nights near 15.3°C. The long-term trend is warming, about 0.2°C per decade.
August is one of the drier months in Dorchester, averaging 61 mm of rainfall. The wettest August on record was 2015 with 171 mm, while the driest was 1995 at 8 mm.
Relative humidity in Dorchester during August averages 83%. The most humid August was 1997 at 88%, and the least humid was 1995 at 77%.
August receives about 4.6 kWh/m²/day of solar energy in Dorchester. The sunniest Augusts were 1995, 2005 and 2022 at 5.3 kWh/m²/day, and the cloudiest was 1986 at 3.6.
Average wind speed in Dorchester during August is 4.6 m/s. The windiest August was 1985 at 6 m/s, while the calmest was 1981 at 3.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 16.6°C | 17.0°C | 17.0°C | 16.9°C | 17.9°C | +1.3°C |
| Avg High | 18.4°C | 18.8°C | 18.6°C | 18.4°C | 19.7°C | +1.3°C |
| Avg Low | 14.8°C | 15.3°C | 15.4°C | 15.3°C | 16.1°C | +1.3°C |
| Avg Rain | 49 mm | 59 mm | 55 mm | 82 mm | 55 mm | +6 mm |
August temperatures in Dorchester have risen by about 1°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 10.7°C (1993) to a record high of 25.8°C (1995).
Rainfall in August is one of the drier months, averaging 61 mm, with a wettest year of 171 mm.
One of the best times to visit Dorchester
August is one of the best times to visit Dorchester. Expect days averaging 18.7°C and nights around 15.3°C (mean 17°C) — warmer than Dorchester's yearly average — with moderate rainfall (61 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 | 20.2°C | 18.4°C | 16.6°C | 25.4°C | 14.9°C | 30 mm | 80% | 4.8 m/s | 4.8 |
| 2024 | 19.4°C | 17.7°C | 16.1°C | 22.1°C | 14.3°C | 77 mm | 84% | 5 m/s | 4.6 |
| 2023 | 18.9°C | 17.3°C | 15.7°C | 21.0°C | 14.0°C | 67 mm | 86% | 4.9 m/s | 4.5 |
| 2022 🔥 | 21.5°C | 19.3°C | 17.1°C | 25.5°C | 14.8°C | 20 mm | 78% | 4 m/s | 5.3 |
| 2021 | 18.5°C | 16.8°C | 15.0°C | 20.1°C | 13.8°C | 40 mm | 85% | 4.8 m/s | 4.6 |
| 2020 | 19.8°C | 18.1°C | 16.3°C | 25.1°C | 12.8°C | 94 mm | 82% | 4.8 m/s | 4.5 |
| 2019 | 18.8°C | 17.4°C | 16.0°C | 21.5°C | 14.7°C | 82 mm | 85% | 5.3 m/s | 4.9 |
| 2018 | 19.4°C | 17.6°C | 15.9°C | 24.1°C | 13.4°C | 86 mm | 81% | 4.5 m/s | 4.5 |
| 2017 | 18.2°C | 16.6°C | 15.1°C | 22.7°C | 13.2°C | 82 mm | 83% | 4.8 m/s | 4.7 |
| 2016 | 19.0°C | 17.3°C | 15.6°C | 21.9°C | 13.4°C | 62 mm | 85% | 5 m/s | 5 |
| 2015 🌧️ | 17.8°C | 16.4°C | 14.9°C | 20.4°C | 13.4°C | 171 mm | 85% | 4.7 m/s | 4 |
| 2014 | 18.1°C | 16.6°C | 15.2°C | 20.4°C | 12.7°C | 83 mm | 79% | 5.6 m/s | 4.8 |
| 2013 | 19.1°C | 17.3°C | 15.4°C | 21.9°C | 13.1°C | 26 mm | 83% | 4.3 m/s | 5 |
| 2012 | 18.0°C | 16.8°C | 15.6°C | 21.2°C | 12.3°C | 76 mm | 87% | 5 m/s | 4.5 |
| 2011 | 17.7°C | 16.2°C | 14.8°C | 19.8°C | 13.1°C | 70 mm | 82% | 4.7 m/s | 4.4 |
| 2010 | 18.4°C | 16.6°C | 14.8°C | 20.5°C | 12.1°C | 80 mm | 83% | 5.4 m/s | 4.2 |
| 2009 | 18.2°C | 16.8°C | 15.4°C | 20.2°C | 13.6°C | 51 mm | 86% | 4.9 m/s | 4.4 |
| 2008 | 17.7°C | 16.5°C | 15.3°C | 19.4°C | 13.3°C | 89 mm | 87% | 5.9 m/s | 4 |
| 2007 | 18.4°C | 16.5°C | 14.6°C | 20.5°C | 13.3°C | 50 mm | 82% | 5.1 m/s | 5.1 |
| 2006 | 18.9°C | 17.2°C | 15.5°C | 22.0°C | 14.0°C | 40 mm | 81% | 5.3 m/s | 4.7 |
| 2005 | 19.0°C | 17.0°C | 15.0°C | 22.0°C | 13.3°C | 40 mm | 81% | 4.3 m/s | 5.3 |
| 2004 | 18.4°C | 17.0°C | 15.7°C | 20.0°C | 13.5°C | 127 mm | 87% | 4.8 m/s | 4.6 |
| 2003 | 20.2°C | 18.2°C | 16.2°C | 25.6°C | 13.0°C | 21 mm | 81% | 3.7 m/s | 4.7 |
| 2002 | 18.6°C | 16.9°C | 15.1°C | 20.4°C | 14.1°C | 39 mm | 85% | 3.7 m/s | 4.5 |
| 2001 | 18.5°C | 17.0°C | 15.5°C | 22.1°C | 13.7°C | 49 mm | 85% | 4.6 m/s | 4.2 |
| 2000 | 18.5°C | 17.0°C | 15.5°C | 20.7°C | 14.0°C | 44 mm | 85% | 4.6 m/s | 4.4 |
| 1999 | 18.4°C | 17.1°C | 15.9°C | 20.3°C | 14.1°C | 114 mm | 86% | 4.2 m/s | 4.3 |
| 1998 | 18.7°C | 16.7°C | 14.7°C | 22.1°C | 12.3°C | 23 mm | 82% | 4.3 m/s | 5.2 |
| 1997 | 19.3°C | 17.9°C | 16.6°C | 21.0°C | 15.0°C | 131 mm | 88% | 3.6 m/s | 3.9 |
| 1996 | 18.1°C | 16.4°C | 14.7°C | 20.6°C | 12.9°C | 52 mm | 84% | 4.5 m/s | 4.8 |
| 1995 | 21.3°C | 18.9°C | 16.5°C | 25.8°C | 14.1°C | 8 mm | 77% | 3.9 m/s | 5.3 |
| 1994 | 18.4°C | 16.8°C | 15.3°C | 20.8°C | 13.1°C | 55 mm | 82% | 4.9 m/s | 4.4 |
| 1993 | 17.8°C | 15.8°C | 13.9°C | 20.3°C | 10.7°C | 51 mm | 81% | 4.5 m/s | 4.8 |
| 1992 | 17.8°C | 16.3°C | 14.9°C | 19.7°C | 12.2°C | 109 mm | 84% | 5.6 m/s | 3.9 |
| 1991 | 18.7°C | 16.9°C | 15.1°C | 21.5°C | 13.3°C | 20 mm | 84% | 4 m/s | 4.8 |
| 1990 | 19.7°C | 17.7°C | 15.7°C | 25.4°C | 13.7°C | 24 mm | 81% | 4 m/s | 4.8 |
| 1989 | 19.6°C | 17.7°C | 15.7°C | 21.0°C | 13.4°C | 36 mm | 79% | 4.6 m/s | 5 |
| 1988 | 17.3°C | 15.7°C | 14.0°C | 20.0°C | 11.6°C | 40 mm | 84% | 4.9 m/s | 4.3 |
| 1987 | 18.6°C | 16.7°C | 14.7°C | 23.1°C | 12.3°C | 24 mm | 81% | 3.8 m/s | 4.3 |
| 1986 ❄️ | 16.2°C | 14.7°C | 13.2°C | 17.8°C | 10.9°C | 105 mm | 82% | 4.7 m/s | 3.6 |
| 1985 | 16.6°C | 15.2°C | 13.9°C | 18.2°C | 12.6°C | 93 mm | 85% | 6 m/s | 4.1 |
| 1984 | 19.4°C | 17.6°C | 15.8°C | 23.1°C | 12.7°C | 38 mm | 82% | 3.6 m/s | 4.4 |
| 1983 | 20.1°C | 17.9°C | 15.7°C | 22.3°C | 13.2°C | 24 mm | 80% | 4 m/s | — |
| 1982 | 18.5°C | 16.8°C | 15.1°C | 23.8°C | 11.9°C | 56 mm | 82% | 5.1 m/s | — |
| 1981 | 19.1°C | 17.2°C | 15.4°C | 22.7°C | 13.0°C | 27 mm | 83% | 3.1 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 18.7°C with lows near 15.3°C (mean 17°C), based on 45 years of NASA POWER data.
August averages 61 mm of rainfall in Dorchester, one of the drier months. The wettest on record was 171 mm in 2015.
The hottest August reached 25.8°C in 1995. The coldest dipped to 10.7°C in 1993.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1°C. Daytime highs moved from 18.7°C to 19.7°C and overnight lows from 15.2°C to 16.1°C over the same span.
August is one of the warmer months of the year in Dorchester and one of the drier months, so plan for around 18.7°C daytime highs and 15.3°C at night.
Not quite — August is the 12th coolest month in Dorchester, averaging 17°C.
For August in Dorchester, pack light layers you can adjust through the day, with typical highs of 18.7°C and lows of 15.3°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 83% — quite humid.
Average wind speed in August is 4.6 m/s. The windiest August on record averaged 6 m/s (1985).
The wettest August on record was 2015 with 171 mm. On average, August sees 61 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 Dorchester 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.
