August is one of the cooler months of the year in Sunbury, with average highs near 12.7°C and lows around 4°C (mean 8.4°C). It is about average for rainfall, averaging 69 mm of rainfall and 85% relative humidity across the period.
August is one of the cooler months of the year in Sunbury. Across 45 years of records, the warmest August in Sunbury was 2024 — when the month averaged 11°C — while the coldest was 1992 at 6.7°C. Typical August days reach 12.7°C with nights near 4°C. The long-term trend is warming, about 0.3°C per decade.
August is about average for rainfall in Sunbury, averaging 69 mm of rainfall. The wettest August on record was 1981 with 136 mm, while the driest was 1982 at 23 mm.
Relative humidity in Sunbury during August averages 85%. The most humid August was 1989 at 90%, and the least humid was 2018 at 76%.
August receives about 2.9 kWh/m²/day of solar energy in Sunbury. The sunniest August was 2006 at 3.3 kWh/m²/day, and the cloudiest were 2010 and 2022 at 2.5.
Average wind speed in Sunbury during August is 2.3 m/s. The windiest August was 1991 at 3.1 m/s, while the calmest were 1998 and 2014 at 1.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 8.1°C | 7.9°C | 8.6°C | 8.3°C | 9.3°C | +1.2°C |
| Avg High | 12.3°C | 12.1°C | 13.1°C | 12.6°C | 13.9°C | +1.6°C |
| Avg Low | 3.9°C | 3.7°C | 4.0°C | 4.1°C | 4.8°C | +0.9°C |
| Avg Rain | 84 mm | 76 mm | 66 mm | 63 mm | 48 mm | -36 mm |
August temperatures in Sunbury have risen by about 1.3°C between 1981–1985 and 2021–2025.
August has ranged from a record low of -1.9°C (2003) to a record high of 21.7°C (1982).
Rainfall in August is about average for rainfall, averaging 69 mm, with a wettest year of 136 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.4°C per decade while lows rose 0.2°C per decade, widening the gap between day and night.
A quieter season to visit Sunbury
If your dates are flexible, the more temperate months of February and January tend to be the most comfortable for visiting Sunbury. That said, August — with days averaging 12.7°C and nights around 4°C (mean 8.4°C) and moderate rainfall (69 mm) — can still be rewarding for travellers who don't mind the cooler conditions, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 14.1°C | 9.1°C | 4.1°C | 19.2°C | 0.9°C | 45 mm | 81% | 2 m/s | 3.1 |
| 2024 🔥 | 15.8°C | 11.0°C | 6.2°C | 20.1°C | 1.4°C | 29 mm | 79% | 2.3 m/s | 2.9 |
| 2023 | 14.7°C | 9.7°C | 4.8°C | 18.9°C | 0.5°C | 30 mm | 83% | 2 m/s | 2.8 |
| 2022 | 13.0°C | 9.1°C | 5.2°C | 16.9°C | 0.8°C | 91 mm | 86% | 2.4 m/s | 2.5 |
| 2021 | 13.5°C | 9.0°C | 4.6°C | 18.4°C | 1.3°C | 29 mm | 83% | 2.3 m/s | 3 |
| 2020 | 12.1°C | 8.0°C | 4.0°C | 16.2°C | 0.4°C | 62 mm | 87% | 2.4 m/s | 2.9 |
| 2019 | 12.6°C | 7.9°C | 3.3°C | 16.4°C | 1.1°C | 52 mm | 82% | 2.4 m/s | 2.9 |
| 2018 | 12.8°C | 8.1°C | 3.5°C | 16.8°C | -0.8°C | 40 mm | 76% | 2.7 m/s | 3 |
| 2017 | 12.5°C | 8.3°C | 4.1°C | 18.1°C | 1.1°C | 59 mm | 82% | 2.4 m/s | 2.9 |
| 2016 | 13.0°C | 8.7°C | 4.4°C | 17.6°C | 1.1°C | 73 mm | 84% | 2.3 m/s | 2.9 |
| 2015 | 11.9°C | 7.7°C | 3.6°C | 17.1°C | -0.7°C | 44 mm | 84% | 2.2 m/s | 2.6 |
| 2014 | 13.2°C | 8.7°C | 4.1°C | 18.8°C | 0.5°C | 27 mm | 85% | 1.7 m/s | 3 |
| 2013 | 12.6°C | 8.7°C | 4.8°C | 18.9°C | 1.6°C | 93 mm | 86% | 2.9 m/s | 2.8 |
| 2012 | 11.6°C | 7.8°C | 3.9°C | 16.1°C | 0.7°C | 79 mm | 86% | 2.7 m/s | 2.9 |
| 2011 | 14.3°C | 9.7°C | 5.1°C | 19.1°C | 1.2°C | 47 mm | 84% | 1.8 m/s | 2.8 |
| 2010 | 11.1°C | 7.4°C | 3.7°C | 14.8°C | 0.4°C | 116 mm | 88% | 2.6 m/s | 2.5 |
| 2009 | 14.0°C | 9.3°C | 4.6°C | 17.0°C | 0.1°C | 60 mm | 80% | 2.9 m/s | 2.9 |
| 2008 | 11.4°C | 7.3°C | 3.3°C | 15.6°C | 0.4°C | 74 mm | 87% | 2.2 m/s | 2.6 |
| 2007 | 13.8°C | 9.3°C | 4.7°C | 20.6°C | 1.6°C | 34 mm | 84% | 2.3 m/s | 3.1 |
| 2006 | 14.3°C | 9.2°C | 4.0°C | 19.4°C | 1.7°C | 30 mm | 79% | 1.8 m/s | 3.3 |
| 2005 | 13.3°C | 8.7°C | 4.0°C | 17.8°C | 0.6°C | 92 mm | 83% | 2.8 m/s | 3 |
| 2004 | 13.0°C | 8.6°C | 4.2°C | 18.5°C | -0.3°C | 83 mm | 84% | 2.1 m/s | 2.8 |
| 2003 | 11.6°C | 7.4°C | 3.2°C | 15.3°C | -1.9°C | 95 mm | 84% | 2.6 m/s | 2.8 |
| 2002 | 13.4°C | 8.8°C | 4.1°C | 16.5°C | 1.4°C | 41 mm | 80% | 2.1 m/s | 2.9 |
| 2001 | 13.0°C | 8.5°C | 4.0°C | 16.7°C | 1.2°C | 87 mm | 81% | 2.7 m/s | 2.6 |
| 2000 | 12.8°C | 8.4°C | 3.9°C | 16.9°C | 1.4°C | 62 mm | 86% | 1.8 m/s | 2.8 |
| 1999 | 13.3°C | 9.2°C | 5.2°C | 19.5°C | 1.4°C | 100 mm | 87% | 2.3 m/s | 2.8 |
| 1998 | 13.5°C | 9.1°C | 4.6°C | 18.0°C | 1.2°C | 34 mm | 86% | 1.7 m/s | 3 |
| 1997 | 12.2°C | 7.6°C | 3.1°C | 15.9°C | -0.9°C | 69 mm | 82% | 2.3 m/s | 2.8 |
| 1996 | 11.5°C | 7.8°C | 4.1°C | 14.7°C | 1.5°C | 80 mm | 89% | 2.5 m/s | 2.7 |
| 1995 | 12.7°C | 8.1°C | 3.5°C | 18.6°C | 0.3°C | 49 mm | 88% | 2.3 m/s | 3.2 |
| 1994 | 11.8°C | 7.2°C | 2.5°C | 18.7°C | -0.4°C | 32 mm | 83% | 2.1 m/s | 3.2 |
| 1993 | 13.7°C | 8.8°C | 3.9°C | 18.1°C | -0.9°C | 97 mm | 84% | 2.4 m/s | 2.9 |
| 1992 ❄️ | 10.9°C | 6.7°C | 2.6°C | 14.9°C | -1.1°C | 102 mm | 87% | 2.5 m/s | 2.8 |
| 1991 | 11.1°C | 7.2°C | 3.3°C | 14.7°C | 0.3°C | 100 mm | 87% | 3.1 m/s | 2.7 |
| 1990 | 10.4°C | 7.2°C | 3.9°C | 15.5°C | -0.2°C | 97 mm | 90% | 2.6 m/s | 2.8 |
| 1989 | 10.6°C | 6.9°C | 3.1°C | 14.3°C | -0.1°C | 97 mm | 90% | 2 m/s | 2.8 |
| 1988 | 12.7°C | 8.5°C | 4.3°C | 17.6°C | 1.7°C | 61 mm | 87% | 2.3 m/s | 2.8 |
| 1987 | 12.3°C | 8.3°C | 4.2°C | 15.4°C | 1.1°C | 52 mm | 88% | 2 m/s | 2.9 |
| 1986 | 12.3°C | 7.7°C | 3.2°C | 16.2°C | -0.5°C | 65 mm | 87% | 2 m/s | 3 |
| 1985 | 11.4°C | 7.3°C | 3.2°C | 15.3°C | -0.8°C | 123 mm | 88% | 2.3 m/s | 2.6 |
| 1984 | 11.9°C | 8.3°C | 4.8°C | 16.2°C | 2.7°C | 112 mm | 88% | 2.8 m/s | 2.8 |
| 1983 | 12.7°C | 8.7°C | 4.7°C | 16.7°C | -0.3°C | 83 mm | 88% | 2.3 m/s | — |
| 1982 | 15.7°C | 9.8°C | 3.9°C | 21.7°C | 0.0°C | 23 mm | 77% | 1.8 m/s | — |
| 1981 🌧️ | 11.0°C | 7.4°C | 3.7°C | 14.1°C | 0.1°C | 136 mm | 89% | 2.6 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 12.7°C with lows near 4°C (mean 8.4°C), based on 45 years of NASA POWER data.
August averages 69 mm of rainfall in Sunbury, about average for rainfall. The wettest on record was 136 mm in 1981.
The hottest August reached 21.7°C in 1982. The coldest dipped to -1.9°C in 2003.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1.3°C. Daytime highs moved from 12.5°C to 14.2°C and overnight lows from 4.1°C to 5°C over the same span.
August is one of the cooler months of the year in Sunbury and about average for rainfall, so plan for around 12.7°C daytime highs and 4°C at night.
Not quite — August is the 3rd coolest month in Sunbury, averaging 8.4°C.
For August in Sunbury, pack warm layers and a jacket for chilly mornings, with typical highs of 12.7°C and lows of 4°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 85% — quite humid.
Average wind speed in August is 2.3 m/s. The windiest August on record averaged 3.1 m/s (1991).
The wettest August on record was 1981 with 136 mm. On average, August sees 69 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 Sunbury 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.
