August is one of the cooler months of the year in Hamilton, with average highs near 12.8°C and lows around 4.4°C (mean 8.6°C). It is a relatively wet time of year, averaging 75 mm of rainfall and 86% relative humidity across the period.
August is one of the cooler months of the year in Hamilton. Across 45 years of records, the warmest August in Hamilton was 2024 — when the month averaged 11.6°C — while the coldest was 1989 at 7°C. Typical August days reach 12.8°C with nights near 4.4°C. The long-term trend is warming, about 0.2°C per decade.
August is a relatively wet time of year in Hamilton, averaging 75 mm of rainfall. The wettest August on record was 1981 with 143 mm, while the driest was 1982 at 14 mm.
Relative humidity in Hamilton during August averages 86%. The most humid August was 1989 at 90%, and the least humid were 1982 and 2024 at 77%.
August receives about 2.9 kWh/m²/day of solar energy in Hamilton. The sunniest Augusts were 1995, 2006 and 2007 at 3.2 kWh/m²/day, and the cloudiest were 2008 and 2010 at 2.6.
Average wind speed in Hamilton during August is 3 m/s. The windiest August was 1991 at 4.1 m/s, while the calmest was 2014 at 2.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 8.5°C | 8.3°C | 8.6°C | 8.5°C | 9.6°C | +1.1°C |
| Avg High | 12.5°C | 12.5°C | 13.0°C | 12.5°C | 13.8°C | +1.3°C |
| Avg Low | 4.4°C | 4.1°C | 4.3°C | 4.5°C | 5.3°C | +0.9°C |
| Avg Rain | 84 mm | 82 mm | 75 mm | 73 mm | 53 mm | -30 mm |
August temperatures in Hamilton have risen by about 1.1°C between 1981–1985 and 2021–2025.
August has ranged from a record low of -1.5°C (2003) to a record high of 22.9°C (1982).
Rainfall in August is a relatively wet time of year, averaging 75 mm, with a wettest year of 143 mm.
A quieter season to visit Hamilton
If your dates are flexible, the more temperate months of February and January tend to be the most comfortable for visiting Hamilton. That said, August — with days averaging 12.8°C and nights around 4.4°C (mean 8.6°C) and moderate rainfall (75 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 | 13.7°C | 9.1°C | 4.4°C | 17.0°C | 0.3°C | 55 mm | 82% | 2.8 m/s | 3.1 |
| 2024 🔥 | 16.2°C | 11.6°C | 7.0°C | 21.3°C | 1.8°C | 39 mm | 77% | 3.4 m/s | 3 |
| 2023 | 13.9°C | 9.7°C | 5.4°C | 21.2°C | 0.5°C | 27 mm | 84% | 2.6 m/s | 2.9 |
| 2022 | 13.5°C | 9.5°C | 5.5°C | 18.2°C | 1.2°C | 92 mm | 84% | 3.1 m/s | 2.7 |
| 2021 | 13.2°C | 9.3°C | 5.3°C | 17.7°C | 2.4°C | 50 mm | 86% | 3 m/s | 3 |
| 2020 | 12.4°C | 8.3°C | 4.2°C | 18.8°C | 0.7°C | 57 mm | 87% | 3 m/s | 2.9 |
| 2019 | 12.4°C | 8.2°C | 4.0°C | 17.3°C | -0.5°C | 50 mm | 84% | 3 m/s | 2.9 |
| 2018 | 12.4°C | 8.2°C | 4.1°C | 16.1°C | -0.2°C | 69 mm | 83% | 3.4 m/s | 3.1 |
| 2017 | 12.5°C | 8.2°C | 4.0°C | 17.9°C | 0.4°C | 79 mm | 86% | 3 m/s | 2.9 |
| 2016 | 13.2°C | 9.0°C | 4.8°C | 19.9°C | 1.1°C | 45 mm | 84% | 3 m/s | 2.9 |
| 2015 | 12.1°C | 8.1°C | 4.2°C | 17.2°C | 0.0°C | 23 mm | 84% | 2.8 m/s | 2.8 |
| 2014 | 13.3°C | 8.6°C | 3.9°C | 18.8°C | -1.3°C | 25 mm | 86% | 2.1 m/s | 3.1 |
| 2013 | 12.6°C | 9.0°C | 5.5°C | 19.0°C | 2.5°C | 142 mm | 89% | 3.7 m/s | 2.8 |
| 2012 | 11.9°C | 8.1°C | 4.2°C | 17.1°C | 2.0°C | 93 mm | 88% | 3.5 m/s | 2.8 |
| 2011 | 13.8°C | 9.8°C | 5.8°C | 19.8°C | 1.6°C | 74 mm | 88% | 2.6 m/s | 2.8 |
| 2010 | 10.9°C | 7.5°C | 4.1°C | 15.6°C | 0.0°C | 134 mm | 89% | 3.4 m/s | 2.6 |
| 2009 | 13.7°C | 9.5°C | 5.4°C | 18.9°C | 1.2°C | 80 mm | 85% | 3.7 m/s | 2.9 |
| 2008 | 11.0°C | 7.3°C | 3.6°C | 15.3°C | 0.2°C | 77 mm | 89% | 2.8 m/s | 2.6 |
| 2007 | 13.7°C | 9.3°C | 4.9°C | 20.7°C | -0.4°C | 52 mm | 85% | 3 m/s | 3.2 |
| 2006 | 14.6°C | 9.3°C | 4.0°C | 20.9°C | 2.0°C | 34 mm | 80% | 2.5 m/s | 3.2 |
| 2005 | 13.8°C | 9.0°C | 4.3°C | 21.3°C | 0.7°C | 84 mm | 82% | 3.4 m/s | 2.9 |
| 2004 | 12.6°C | 8.5°C | 4.4°C | 18.4°C | 0.6°C | 92 mm | 86% | 2.8 m/s | 2.7 |
| 2003 | 11.7°C | 7.5°C | 3.4°C | 16.1°C | -1.5°C | 98 mm | 86% | 3.3 m/s | 2.9 |
| 2002 | 12.9°C | 8.4°C | 3.8°C | 17.6°C | 0.3°C | 44 mm | 83% | 2.7 m/s | 2.9 |
| 2001 | 13.2°C | 9.0°C | 4.9°C | 18.6°C | 1.8°C | 126 mm | 83% | 3.4 m/s | 2.7 |
| 2000 | 13.0°C | 8.4°C | 3.8°C | 17.4°C | 1.0°C | 58 mm | 86% | 2.4 m/s | 2.9 |
| 1999 | 14.1°C | 9.4°C | 4.7°C | 21.6°C | 1.7°C | 63 mm | 85% | 2.6 m/s | 2.9 |
| 1998 | 13.8°C | 9.1°C | 4.4°C | 17.9°C | -0.1°C | 37 mm | 85% | 2.4 m/s | 3.1 |
| 1997 | 12.5°C | 8.2°C | 3.9°C | 17.2°C | 0.0°C | 68 mm | 84% | 3 m/s | 2.8 |
| 1996 | 11.9°C | 8.2°C | 4.5°C | 16.7°C | 1.2°C | 96 mm | 89% | 3.2 m/s | 2.7 |
| 1995 | 13.2°C | 8.7°C | 4.1°C | 20.7°C | 0.7°C | 54 mm | 88% | 3.1 m/s | 3.2 |
| 1994 | 11.6°C | 7.3°C | 3.0°C | 19.3°C | -0.6°C | 42 mm | 86% | 2.6 m/s | 3.1 |
| 1993 | 14.2°C | 9.6°C | 5.0°C | 19.4°C | 0.7°C | 88 mm | 83% | 3.2 m/s | 3 |
| 1992 | 11.2°C | 7.2°C | 3.3°C | 16.7°C | 0.9°C | 119 mm | 88% | 3.3 m/s | 2.9 |
| 1991 | 11.6°C | 7.9°C | 4.1°C | 15.6°C | 0.9°C | 139 mm | 88% | 4.1 m/s | 2.8 |
| 1990 | 11.0°C | 7.5°C | 4.0°C | 14.5°C | -1.4°C | 114 mm | 90% | 3.3 m/s | 2.8 |
| 1989 ❄️ | 10.8°C | 7.0°C | 3.3°C | 13.5°C | -0.2°C | 99 mm | 90% | 2.9 m/s | 2.8 |
| 1988 | 12.5°C | 8.8°C | 5.1°C | 18.5°C | 2.6°C | 74 mm | 88% | 3.1 m/s | 2.8 |
| 1987 | 12.5°C | 8.2°C | 4.0°C | 17.0°C | 0.5°C | 53 mm | 88% | 2.6 m/s | 2.9 |
| 1986 | 12.5°C | 8.5°C | 4.5°C | 18.0°C | 0.0°C | 71 mm | 87% | 3 m/s | 3.1 |
| 1985 | 12.1°C | 8.1°C | 4.1°C | 17.2°C | -1.1°C | 95 mm | 87% | 3 m/s | 2.8 |
| 1984 | 12.2°C | 8.8°C | 5.4°C | 16.9°C | 3.5°C | 115 mm | 88% | 3.5 m/s | 2.8 |
| 1983 | 13.1°C | 9.1°C | 5.2°C | 16.6°C | -0.1°C | 90 mm | 87% | 3 m/s | — |
| 1982 | 15.8°C | 10.0°C | 4.1°C | 22.9°C | 1.0°C | 14 mm | 77% | 2.3 m/s | — |
| 1981 🌧️ | 11.4°C | 7.7°C | 4.0°C | 15.0°C | -0.4°C | 143 mm | 89% | 3.5 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 12.8°C with lows near 4.4°C (mean 8.6°C), based on 45 years of NASA POWER data.
August averages 75 mm of rainfall in Hamilton, a relatively wet time of year. The wettest on record was 143 mm in 1981.
The hottest August reached 22.9°C in 1982. The coldest dipped to -1.5°C in 2003.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1.1°C. Daytime highs moved from 12.9°C to 14.1°C and overnight lows from 4.6°C to 5.5°C over the same span.
August is one of the cooler months of the year in Hamilton and a relatively wet time of year, so plan for around 12.8°C daytime highs and 4.4°C at night.
Not quite — August is the 2nd coolest month in Hamilton, averaging 8.6°C.
For August in Hamilton, pack warm layers and a jacket for chilly mornings, with typical highs of 12.8°C and lows of 4.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 86% — quite humid.
Average wind speed in August is 3 m/s. The windiest August on record averaged 4.1 m/s (1991).
The wettest August on record was 1981 with 143 mm. On average, August sees 75 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 Hamilton 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.
