August is one of the cooler months of the year in Horsham, with average highs near 14.9°C and lows around 4.4°C (mean 9.7°C). It is a relatively wet time of year, averaging 50 mm of rainfall and 80% relative humidity across the period.
August is one of the cooler months of the year in Horsham. Across 45 years of records, the warmest August in Horsham was 2024 — when the month averaged 12.4°C — while the coldest was 1989 at 7.9°C. Typical August days reach 14.9°C with nights near 4.4°C. The long-term August temperature trend is broadly flat.
August is a relatively wet time of year in Horsham, averaging 50 mm of rainfall. The wettest August on record was 1981 with 104 mm, while the driest was 2014 at 7 mm.
Relative humidity in Horsham during August averages 80%. The most humid August was 1989 at 86%, and the least humid was 1982 at 68%.
August receives about 3.2 kWh/m²/day of solar energy in Horsham. The sunniest Augusts were 2006, 2007 and 2014 at 3.6 kWh/m²/day, and the cloudiest was 2010 at 2.8.
Average wind speed in Horsham during August is 2.9 m/s. The windiest August was 1991 at 4 m/s, while the calmest were 1982, 2006 and 2014 at 2.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 9.5°C | 9.4°C | 9.7°C | 9.5°C | 10.3°C | +0.8°C |
| Avg High | 14.6°C | 14.7°C | 15.3°C | 14.6°C | 15.5°C | +0.9°C |
| Avg Low | 4.4°C | 4.1°C | 4.2°C | 4.5°C | 5.2°C | +0.8°C |
| Avg Rain | 58 mm | 51 mm | 42 mm | 50 mm | 52 mm | -6 mm |
August temperatures in Horsham have risen by about 0.7°C between 1981–1985 and 2021–2025.
August has ranged from a record low of -1°C (1994) to a record high of 26.4°C (1982).
Rainfall in August is a relatively wet time of year, averaging 50 mm, with a wettest year of 104 mm.
A quieter season to visit Horsham
If your dates are flexible, the more temperate months of February and January tend to be the most comfortable for visiting Horsham. That said, August — with days averaging 14.9°C and nights around 4.4°C (mean 9.7°C) and moderate rainfall (50 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 | 15.1°C | 9.9°C | 4.7°C | 18.7°C | 0.0°C | 52 mm | 78% | 2.8 m/s | 3.4 |
| 2024 🔥 | 18.0°C | 12.4°C | 6.8°C | 24.5°C | 0.6°C | 37 mm | 72% | 3 m/s | 3.3 |
| 2023 | 15.5°C | 10.2°C | 5.0°C | 21.3°C | 0.6°C | 31 mm | 81% | 2.3 m/s | 3.2 |
| 2022 | 15.3°C | 10.4°C | 5.6°C | 20.1°C | 2.0°C | 88 mm | 79% | 3 m/s | 3.1 |
| 2021 | 14.9°C | 9.9°C | 4.9°C | 20.3°C | 0.8°C | 42 mm | 82% | 2.7 m/s | 3.3 |
| 2020 | 14.0°C | 9.1°C | 4.1°C | 20.3°C | 0.6°C | 62 mm | 82% | 2.9 m/s | 3.3 |
| 2019 | 14.0°C | 8.7°C | 3.4°C | 19.6°C | 0.4°C | 50 mm | 81% | 3 m/s | 3.2 |
| 2018 | 14.1°C | 9.0°C | 4.0°C | 19.1°C | 0.0°C | 64 mm | 78% | 3.3 m/s | 3.3 |
| 2017 | 14.0°C | 9.0°C | 4.1°C | 19.8°C | 0.4°C | 80 mm | 82% | 3 m/s | 3.2 |
| 2016 | 15.5°C | 10.2°C | 4.9°C | 22.1°C | 1.7°C | 23 mm | 77% | 2.8 m/s | 3.2 |
| 2015 | 14.2°C | 9.3°C | 4.4°C | 19.6°C | 0.2°C | 17 mm | 78% | 2.7 m/s | 3.1 |
| 2014 | 15.6°C | 9.9°C | 4.1°C | 23.0°C | -0.3°C | 7 mm | 78% | 2.2 m/s | 3.6 |
| 2013 | 14.6°C | 10.2°C | 5.8°C | 22.0°C | 2.0°C | 64 mm | 83% | 3.4 m/s | 3 |
| 2012 | 14.4°C | 9.3°C | 4.3°C | 19.9°C | 1.2°C | 47 mm | 80% | 3.3 m/s | 3 |
| 2011 | 16.2°C | 10.9°C | 5.7°C | 23.1°C | 1.1°C | 49 mm | 80% | 2.4 m/s | 3.1 |
| 2010 | 12.9°C | 8.4°C | 4.0°C | 17.3°C | 0.8°C | 96 mm | 84% | 3.4 m/s | 2.8 |
| 2009 | 15.9°C | 10.7°C | 5.4°C | 22.2°C | 0.6°C | 40 mm | 77% | 3.5 m/s | 3.2 |
| 2008 | 12.9°C | 8.1°C | 3.3°C | 18.4°C | 0.6°C | 44 mm | 83% | 2.9 m/s | 3 |
| 2007 | 16.1°C | 10.4°C | 4.7°C | 23.8°C | 0.3°C | 14 mm | 77% | 2.9 m/s | 3.6 |
| 2006 | 16.8°C | 10.5°C | 4.1°C | 23.2°C | 1.4°C | 17 mm | 73% | 2.2 m/s | 3.6 |
| 2005 | 16.0°C | 10.1°C | 4.2°C | 23.8°C | 0.5°C | 50 mm | 75% | 3.2 m/s | 3.2 |
| 2004 | 14.9°C | 9.7°C | 4.5°C | 23.1°C | 0.1°C | 52 mm | 78% | 2.7 m/s | 3.1 |
| 2003 | 13.8°C | 8.5°C | 3.2°C | 19.5°C | -0.9°C | 79 mm | 79% | 3.2 m/s | 3.1 |
| 2002 | 15.7°C | 9.7°C | 3.8°C | 21.2°C | 0.1°C | 24 mm | 74% | 2.6 m/s | 3.3 |
| 2001 | 15.7°C | 10.2°C | 4.7°C | 21.0°C | 2.1°C | 66 mm | 74% | 3.5 m/s | 3.1 |
| 2000 | 14.8°C | 9.5°C | 4.2°C | 19.8°C | 1.2°C | 31 mm | 79% | 2.5 m/s | 3.2 |
| 1999 | 16.1°C | 10.4°C | 4.8°C | 23.7°C | 0.9°C | 62 mm | 79% | 2.8 m/s | 3.3 |
| 1998 | 16.1°C | 10.4°C | 4.7°C | 20.6°C | 0.7°C | 20 mm | 79% | 2.3 m/s | 3.4 |
| 1997 | 14.7°C | 9.3°C | 4.0°C | 19.8°C | 0.6°C | 52 mm | 77% | 2.9 m/s | 3.2 |
| 1996 | 13.8°C | 9.2°C | 4.6°C | 17.5°C | 1.6°C | 56 mm | 84% | 3.1 m/s | 3.1 |
| 1995 | 15.2°C | 9.5°C | 3.9°C | 22.2°C | 0.0°C | 24 mm | 83% | 2.8 m/s | 3.5 |
| 1994 | 14.0°C | 8.3°C | 2.6°C | 22.1°C | -1.0°C | 14 mm | 78% | 2.6 m/s | 3.5 |
| 1993 | 16.6°C | 10.7°C | 4.8°C | 21.2°C | -0.1°C | 58 mm | 76% | 3 m/s | 3.3 |
| 1992 | 13.0°C | 8.3°C | 3.5°C | 18.8°C | 0.8°C | 89 mm | 82% | 3.2 m/s | 3.2 |
| 1991 | 13.6°C | 8.9°C | 4.2°C | 17.4°C | 0.5°C | 72 mm | 83% | 4 m/s | 3.1 |
| 1990 | 13.4°C | 8.8°C | 4.2°C | 17.4°C | -0.4°C | 61 mm | 84% | 3.5 m/s | 3.2 |
| 1989 ❄️ | 12.5°C | 7.9°C | 3.3°C | 16.1°C | -0.3°C | 57 mm | 86% | 2.8 m/s | 3 |
| 1988 | 14.8°C | 9.8°C | 4.8°C | 21.5°C | 1.7°C | 25 mm | 82% | 3 m/s | 3 |
| 1987 | 14.4°C | 9.3°C | 4.3°C | 18.9°C | 0.7°C | 31 mm | 83% | 2.7 m/s | 3.2 |
| 1986 | 14.3°C | 9.3°C | 4.2°C | 19.7°C | -0.4°C | 50 mm | 82% | 2.8 m/s | 3.3 |
| 1985 | 14.3°C | 9.2°C | 4.1°C | 19.6°C | -0.5°C | 90 mm | 79% | 3 m/s | 2.9 |
| 1984 | 14.4°C | 9.9°C | 5.4°C | 20.0°C | 3.4°C | 82 mm | 81% | 3.5 m/s | 3.3 |
| 1983 | 14.9°C | 10.0°C | 5.0°C | 18.9°C | 0.0°C | 71 mm | 82% | 2.9 m/s | — |
| 1982 | 18.7°C | 11.5°C | 4.3°C | 26.4°C | 1.2°C | 9 mm | 68% | 2.2 m/s | — |
| 1981 🌧️ | 13.3°C | 8.7°C | 4.1°C | 17.0°C | 0.3°C | 104 mm | 84% | 3.4 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 14.9°C with lows near 4.4°C (mean 9.7°C), based on 45 years of NASA POWER data.
August averages 50 mm of rainfall in Horsham, a relatively wet time of year. The wettest on record was 104 mm in 1981.
The hottest August reached 26.4°C in 1982. The coldest dipped to -1°C in 1994.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 0.7°C. Daytime highs moved from 15.1°C to 15.8°C and overnight lows from 4.6°C to 5.4°C over the same span.
August is one of the cooler months of the year in Horsham and a relatively wet time of year, so plan for around 14.9°C daytime highs and 4.4°C at night.
Not quite — August is the 3rd coolest month in Horsham, averaging 9.7°C.
For August in Horsham, pack warm layers and a jacket for chilly mornings, with typical highs of 14.9°C and lows of 4.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 80% — quite humid.
Average wind speed in August is 2.9 m/s. The windiest August on record averaged 4 m/s (1991).
The wettest August on record was 1981 with 104 mm. On average, August sees 50 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 Horsham 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.
