August is one of the cooler months of the year in Onslow, with average highs near 24.8°C and lows around 18.1°C (mean 21.5°C). It is one of the drier months, averaging 6 mm of rainfall and 62% relative humidity across the period.
August is one of the cooler months of the year in Onslow. Across 45 years of records, the warmest August in Onslow was 1982 — when the month averaged 22.7°C — while the coldest was 1986 at 19.5°C. Typical August days reach 24.8°C with nights near 18.1°C. The long-term August temperature trend is broadly flat.
August is one of the drier months in Onslow, averaging 6 mm of rainfall. The wettest August on record was 2025 with 38 mm, while the driest were 2013, 2014 and 2015, among others at 0 mm.
Relative humidity in Onslow during August averages 62%. The most humid August was 1998 at 69%, and the least humid was 2008 at 56%.
August receives about 5.3 kWh/m²/day of solar energy in Onslow. The sunniest August was 2018 at 5.7 kWh/m²/day, and the cloudiest were 1990 and 2010 at 4.8.
Average wind speed in Onslow during August is 4.3 m/s. The windiest August was 2004 at 5.2 m/s, while the calmest were 2006 and 2011 at 3.5 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 21.4°C | 21.4°C | 21.2°C | 21.4°C | 21.9°C | +0.5°C |
| Avg High | 24.8°C | 24.8°C | 24.6°C | 24.7°C | 25.1°C | +0.3°C |
| Avg Low | 18.0°C | 18.1°C | 17.9°C | 18.1°C | 18.6°C | +0.6°C |
| Avg Rain | 3 mm | 9 mm | 3 mm | 2 mm | 13 mm | +10 mm |
August temperatures in Onslow have stayed relatively stable across the record.
August has ranged from a record low of 11.3°C (1986) to a record high of 30°C (2020).
Rainfall in August is one of the drier months, averaging 6 mm, with a wettest year of 38 mm.
One of the best times to visit Onslow
August is one of the best times to visit Onslow. Expect days averaging 24.8°C and nights around 18.1°C (mean 21.5°C) — cooler than Onslow's yearly average — with low rainfall (6 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 🌧️ | 24.7°C | 21.7°C | 18.7°C | 27.5°C | 15.5°C | 38 mm | 63% | 3.9 m/s | 5 |
| 2024 | 25.2°C | 22.0°C | 18.7°C | 28.1°C | 16.5°C | 18 mm | 66% | 4.1 m/s | 5.3 |
| 2023 | 25.7°C | 22.4°C | 19.0°C | 29.5°C | 16.4°C | 3 mm | 62% | 3.6 m/s | 5.3 |
| 2022 | 24.6°C | 21.4°C | 18.2°C | 27.0°C | 13.8°C | 10 mm | 62% | 4.4 m/s | 5.2 |
| 2021 | 25.1°C | 21.7°C | 18.3°C | 28.2°C | 15.0°C | 6 mm | 60% | 4.1 m/s | 5.5 |
| 2020 | 25.4°C | 22.1°C | 18.7°C | 30.0°C | 15.6°C | 4 mm | 59% | 4.5 m/s | 5.5 |
| 2019 | 24.6°C | 21.2°C | 17.8°C | 26.2°C | 15.1°C | 2 mm | 60% | 4.3 m/s | 5.6 |
| 2018 | 23.6°C | 20.1°C | 16.6°C | 26.3°C | 14.2°C | 1 mm | 59% | 4.8 m/s | 5.7 |
| 2017 | 24.8°C | 21.6°C | 18.4°C | 29.6°C | 14.2°C | 2 mm | 61% | 4.2 m/s | 5.6 |
| 2016 | 23.5°C | 20.5°C | 17.5°C | 24.9°C | 14.3°C | 2 mm | 65% | 4.4 m/s | 5.3 |
| 2015 | 25.0°C | 21.7°C | 18.4°C | 27.2°C | 16.0°C | 0 mm | 63% | 4.2 m/s | 5.4 |
| 2014 | 25.6°C | 22.1°C | 18.6°C | 27.8°C | 17.0°C | 0 mm | 58% | 3.7 m/s | 5.3 |
| 2013 | 24.8°C | 21.2°C | 17.7°C | 26.5°C | 15.3°C | 0 mm | 62% | 3.9 m/s | 5.4 |
| 2012 | 25.4°C | 21.8°C | 18.2°C | 27.5°C | 16.2°C | 0 mm | 63% | 3.7 m/s | 5.4 |
| 2011 | 25.4°C | 22.2°C | 19.0°C | 28.3°C | 16.5°C | 2 mm | 65% | 3.5 m/s | 5.3 |
| 2010 | 24.6°C | 21.8°C | 19.0°C | 26.5°C | 16.5°C | 9 mm | 61% | 4.1 m/s | 4.8 |
| 2009 | 24.2°C | 21.1°C | 18.0°C | 26.3°C | 16.1°C | 2 mm | 64% | 4.3 m/s | 5.3 |
| 2008 | 24.7°C | 21.3°C | 17.9°C | 26.0°C | 16.1°C | 2 mm | 56% | 3.8 m/s | 5 |
| 2007 | 25.2°C | 21.3°C | 17.5°C | 27.3°C | 15.7°C | 0 mm | 59% | 4.3 m/s | 5.5 |
| 2006 | 25.3°C | 21.8°C | 18.4°C | 27.2°C | 16.4°C | 0 mm | 65% | 3.5 m/s | 5.4 |
| 2005 | 24.2°C | 21.0°C | 17.8°C | 26.1°C | 14.5°C | 10 mm | 64% | 4.5 m/s | 5.1 |
| 2004 | 24.1°C | 20.4°C | 16.8°C | 26.0°C | 15.5°C | 0 mm | 56% | 5.2 m/s | 5.6 |
| 2003 | 24.2°C | 20.9°C | 17.7°C | 27.3°C | 14.7°C | 10 mm | 60% | 4.6 m/s | 5.3 |
| 2002 | 24.6°C | 21.2°C | 17.9°C | 26.1°C | 15.6°C | 0 mm | 62% | 4.5 m/s | 5.6 |
| 2001 | 25.6°C | 22.5°C | 19.4°C | 26.9°C | 16.4°C | 0 mm | 61% | 4.1 m/s | 5.6 |
| 2000 | 24.3°C | 20.9°C | 17.5°C | 26.2°C | 15.2°C | 4 mm | 59% | 4.2 m/s | 5.2 |
| 1999 | 25.6°C | 22.5°C | 19.4°C | 26.9°C | 17.1°C | 0 mm | 62% | 4.2 m/s | 5.1 |
| 1998 | 25.2°C | 21.5°C | 17.8°C | 27.3°C | 15.3°C | 20 mm | 69% | 4 m/s | 5.3 |
| 1997 | 24.2°C | 21.0°C | 17.7°C | 28.6°C | 14.6°C | 31 mm | 62% | 4.3 m/s | 5 |
| 1996 | 24.4°C | 21.0°C | 17.6°C | 26.8°C | 14.8°C | 1 mm | 64% | 4.9 m/s | 5 |
| 1995 | 25.8°C | 22.0°C | 18.1°C | 29.4°C | 16.1°C | 0 mm | 57% | 4.6 m/s | 5.5 |
| 1994 | 25.7°C | 22.2°C | 18.8°C | 27.7°C | 15.9°C | 7 mm | 63% | 3.9 m/s | 5.4 |
| 1993 | 24.2°C | 20.8°C | 17.3°C | 26.9°C | 14.2°C | 9 mm | 61% | 4.7 m/s | 5.2 |
| 1992 | 23.2°C | 20.2°C | 17.3°C | 25.2°C | 13.2°C | 3 mm | 64% | 5 m/s | 5 |
| 1991 | 25.9°C | 22.4°C | 18.9°C | 28.6°C | 17.1°C | 0 mm | 59% | 4.1 m/s | 5.4 |
| 1990 | 23.9°C | 20.8°C | 17.7°C | 26.7°C | 15.3°C | 20 mm | 68% | 4.8 m/s | 4.8 |
| 1989 | 24.8°C | 21.2°C | 17.7°C | 26.9°C | 14.4°C | 0 mm | 58% | 4.1 m/s | 5.5 |
| 1988 | 25.6°C | 22.4°C | 19.3°C | 27.7°C | 17.2°C | 3 mm | 63% | 4.4 m/s | 5.1 |
| 1987 | 25.1°C | 21.5°C | 18.0°C | 27.4°C | 15.7°C | 0 mm | 59% | 4.4 m/s | 5.3 |
| 1986 ❄️ | 23.2°C | 19.5°C | 15.9°C | 26.7°C | 11.3°C | 1 mm | 60% | 5 m/s | 5.4 |
| 1985 | 24.5°C | 20.8°C | 17.2°C | 26.5°C | 14.6°C | 0 mm | 60% | 4.6 m/s | 5.5 |
| 1984 | 24.4°C | 20.6°C | 16.9°C | 28.9°C | 13.7°C | 9 mm | 61% | 4.5 m/s | 5.1 |
| 1983 | 25.1°C | 22.1°C | 19.0°C | 27.4°C | 15.7°C | 10 mm | 64% | 4 m/s | — |
| 1982 🔥 | 25.9°C | 22.7°C | 19.6°C | 27.7°C | 15.0°C | 3 mm | 66% | 4 m/s | — |
| 1981 | 24.6°C | 21.6°C | 18.6°C | 27.2°C | 16.0°C | 5 mm | 65% | 4.6 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 24.8°C with lows near 18.1°C (mean 21.5°C), based on 45 years of NASA POWER data.
August averages 6 mm of rainfall in Onslow, one of the drier months. The wettest on record was 38 mm in 2025.
The hottest August reached 30°C in 2020. The coldest dipped to 11.3°C in 1986.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 0.2°C. Daytime highs moved from 24.9°C to 25.1°C and overnight lows from 18.3°C to 18.6°C over the same span.
August is one of the cooler months of the year in Onslow and one of the drier months, so plan for around 24.8°C daytime highs and 18.1°C at night.
Not quite — August is the 2nd coolest month in Onslow, averaging 21.5°C.
For August in Onslow, pack light layers you can adjust through the day, with typical highs of 24.8°C and lows of 18.1°C.
Relative humidity in August averages 62% — moderately humid.
Average wind speed in August is 4.3 m/s. The windiest August on record averaged 5.2 m/s (2004).
The wettest August on record was 2025 with 38 mm. On average, August sees 6 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 Onslow 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.
