August is one of the cooler months of the year in Halfmoon Bay, with average highs near 9.6°C and lows around 7°C (mean 8.3°C). It is one of the drier months, averaging 89 mm of rainfall and 84% relative humidity across the period.
August is one of the cooler months of the year in Halfmoon Bay. Across 45 years of records, the warmest August in Halfmoon Bay was 2013 — when the month averaged 9.6°C — while the coldest was 1992 at 6.5°C. Typical August days reach 9.6°C with nights near 7°C. The long-term trend is warming, about 0.2°C per decade.
August is one of the drier months in Halfmoon Bay, averaging 89 mm of rainfall. The wettest August on record was 1982 with 147 mm, while the driest was 1989 at 29 mm.
Relative humidity in Halfmoon Bay during August averages 84%. The most humid August was 2010 at 87%, and the least humid was 1998 at 81%.
August receives about 2 kWh/m²/day of solar energy in Halfmoon Bay. The sunniest August was 1989 at 2.3 kWh/m²/day, and the cloudiest was 2002 at 1.7.
Average wind speed in Halfmoon Bay during August is 4.3 m/s. The windiest August was 1994 at 5.4 m/s, while the calmest was 1989 at 3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 8.3°C | 7.8°C | 8.3°C | 8.5°C | 8.8°C | +0.5°C |
| Avg High | 9.7°C | 9.1°C | 9.6°C | 9.8°C | 10.2°C | +0.5°C |
| Avg Low | 6.9°C | 6.5°C | 7.0°C | 7.3°C | 7.5°C | +0.6°C |
| Avg Rain | 76 mm | 97 mm | 98 mm | 80 mm | 92 mm | +16 mm |
August temperatures in Halfmoon Bay have risen by about 0.5°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 2°C (2011) to a record high of 15.4°C (2014).
Rainfall in August is one of the drier months, averaging 89 mm, with a wettest year of 147 mm.
A quieter season to visit Halfmoon Bay
If your dates are flexible, the more temperate months of February and March tend to be the most comfortable for visiting Halfmoon Bay. That said, August — with days averaging 9.6°C and nights around 7°C (mean 8.3°C) and higher rainfall (89 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 | 10.2°C | 8.9°C | 7.6°C | 13.4°C | 5.2°C | 65 mm | 82% | 4.2 m/s | 2.2 |
| 2024 | 10.3°C | 9.0°C | 7.6°C | 12.8°C | 3.4°C | 85 mm | 83% | 4.4 m/s | 2.1 |
| 2023 | 9.7°C | 8.4°C | 7.0°C | 12.6°C | 5.1°C | 83 mm | 85% | 4.2 m/s | 1.9 |
| 2022 | 10.4°C | 9.0°C | 7.6°C | 13.8°C | 3.5°C | 116 mm | 84% | 3.8 m/s | 2.2 |
| 2021 | 10.1°C | 8.6°C | 7.1°C | 14.2°C | 4.5°C | 127 mm | 83% | 4.4 m/s | 1.9 |
| 2020 | 10.3°C | 9.0°C | 7.8°C | 14.2°C | 4.6°C | 77 mm | 85% | 4.2 m/s | 2 |
| 2019 | 9.6°C | 8.4°C | 7.1°C | 11.9°C | 4.2°C | 114 mm | 82% | 5.3 m/s | 2 |
| 2018 | 10.4°C | 9.2°C | 8.0°C | 13.2°C | 6.6°C | 49 mm | 85% | 3.6 m/s | 1.9 |
| 2017 | 10.2°C | 8.9°C | 7.7°C | 13.0°C | 3.9°C | 92 mm | 85% | 3.6 m/s | 2 |
| 2016 | 9.5°C | 8.3°C | 7.1°C | 12.6°C | 2.8°C | 49 mm | 84% | 3.8 m/s | 2.1 |
| 2015 | 8.8°C | 7.4°C | 6.1°C | 11.7°C | 3.4°C | 92 mm | 83% | 4 m/s | 2 |
| 2014 | 9.6°C | 8.2°C | 6.8°C | 15.4°C | 4.0°C | 105 mm | 84% | 4.5 m/s | 2 |
| 2013 🔥 | 10.9°C | 9.6°C | 8.3°C | 13.3°C | 6.1°C | 70 mm | 85% | 3.9 m/s | 2 |
| 2012 | 10.4°C | 9.1°C | 7.8°C | 13.3°C | 4.5°C | 55 mm | 86% | 3.7 m/s | 2.2 |
| 2011 | 9.1°C | 7.9°C | 6.7°C | 12.3°C | 2.0°C | 83 mm | 84% | 4.8 m/s | 1.9 |
| 2010 | 9.6°C | 8.3°C | 7.0°C | 12.3°C | 4.6°C | 93 mm | 87% | 3.6 m/s | 2 |
| 2009 | 10.6°C | 9.3°C | 8.1°C | 13.4°C | 5.5°C | 97 mm | 84% | 4.1 m/s | 2 |
| 2008 | 8.7°C | 7.6°C | 6.4°C | 12.0°C | 3.6°C | 99 mm | 84% | 3.9 m/s | 2.1 |
| 2007 | 9.2°C | 8.0°C | 6.8°C | 12.5°C | 3.4°C | 122 mm | 85% | 4.3 m/s | 1.9 |
| 2006 | 9.2°C | 8.0°C | 6.8°C | 12.0°C | 4.7°C | 97 mm | 83% | 4.4 m/s | 2.1 |
| 2005 | 10.7°C | 9.4°C | 8.1°C | 13.5°C | 4.2°C | 98 mm | 84% | 4.3 m/s | 1.9 |
| 2004 | 8.0°C | 6.7°C | 5.4°C | 10.9°C | 3.4°C | 118 mm | 85% | 4.3 m/s | 2 |
| 2003 | 9.8°C | 8.4°C | 7.0°C | 12.4°C | 4.5°C | 82 mm | 83% | 4.2 m/s | 2.1 |
| 2002 | 9.9°C | 8.5°C | 7.2°C | 12.2°C | 4.2°C | 115 mm | 85% | 4.6 m/s | 1.7 |
| 2001 | 10.2°C | 8.8°C | 7.4°C | 12.4°C | 4.7°C | 87 mm | 84% | 3.9 m/s | 1.9 |
| 2000 | 9.3°C | 8.2°C | 7.1°C | 13.5°C | 4.1°C | 65 mm | 84% | 5 m/s | 1.8 |
| 1999 | 9.8°C | 8.4°C | 7.0°C | 12.4°C | 5.2°C | 78 mm | 85% | 4.3 m/s | 2 |
| 1998 | 9.1°C | 7.7°C | 6.4°C | 13.1°C | 2.4°C | 77 mm | 81% | 4.9 m/s | 1.9 |
| 1997 | 9.0°C | 7.7°C | 6.4°C | 12.2°C | 3.5°C | 73 mm | 83% | 4.5 m/s | 2 |
| 1996 | 8.7°C | 7.4°C | 6.1°C | 11.6°C | 2.7°C | 87 mm | 85% | 4.1 m/s | 2 |
| 1995 | 8.7°C | 7.5°C | 6.3°C | 12.1°C | 4.2°C | 145 mm | 83% | 5 m/s | 2.1 |
| 1994 | 9.4°C | 8.1°C | 6.8°C | 12.1°C | 2.9°C | 132 mm | 85% | 5.4 m/s | 2 |
| 1993 | 9.3°C | 7.9°C | 6.5°C | 12.1°C | 4.4°C | 113 mm | 82% | 4.5 m/s | 2.1 |
| 1992 ❄️ | 7.6°C | 6.5°C | 5.4°C | 11.2°C | 3.3°C | 117 mm | 82% | 4.9 m/s | 1.9 |
| 1991 | 9.6°C | 8.4°C | 7.1°C | 12.6°C | 5.0°C | 99 mm | 84% | 4.4 m/s | 1.9 |
| 1990 | 9.7°C | 8.4°C | 7.2°C | 12.8°C | 3.1°C | 48 mm | 83% | 4.3 m/s | 2.2 |
| 1989 | 10.4°C | 9.0°C | 7.7°C | 13.2°C | 4.0°C | 29 mm | 84% | 3 m/s | 2.3 |
| 1988 | 9.1°C | 7.8°C | 6.4°C | 11.9°C | 3.4°C | 90 mm | 84% | 4.8 m/s | 1.9 |
| 1987 | 10.2°C | 8.8°C | 7.4°C | 12.2°C | 4.4°C | 69 mm | 85% | 4 m/s | 2 |
| 1986 | 8.9°C | 7.6°C | 6.3°C | 12.4°C | 4.3°C | 62 mm | 84% | 4.1 m/s | 2.2 |
| 1985 | 10.0°C | 8.5°C | 7.1°C | 12.7°C | 4.0°C | 80 mm | 82% | 4 m/s | 2.1 |
| 1984 | 10.1°C | 8.5°C | 6.8°C | 13.0°C | 3.4°C | 90 mm | 83% | 4.1 m/s | 2.2 |
| 1983 | 9.6°C | 8.3°C | 7.1°C | 11.6°C | 4.6°C | 58 mm | 83% | 4.1 m/s | — |
| 1982 🌧️ | 10.2°C | 8.7°C | 7.2°C | 12.6°C | 4.3°C | 147 mm | 82% | 5.3 m/s | — |
| 1981 | 8.8°C | 7.6°C | 6.4°C | 11.2°C | 4.9°C | 60 mm | 81% | 3.8 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 9.6°C with lows near 7°C (mean 8.3°C), based on 45 years of NASA POWER data.
August averages 89 mm of rainfall in Halfmoon Bay, one of the drier months. The wettest on record was 147 mm in 1982.
The hottest August reached 15.4°C in 2014. The coldest dipped to 2°C in 2011.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 0.5°C. Daytime highs moved from 9.7°C to 10.1°C and overnight lows from 6.9°C to 7.4°C over the same span.
August is one of the cooler months of the year in Halfmoon Bay and one of the drier months, so plan for around 9.6°C daytime highs and 7°C at night.
Not quite — August is the 2nd coolest month in Halfmoon Bay, averaging 8.3°C.
For August in Halfmoon Bay, pack warm layers and a jacket for chilly mornings, with typical highs of 9.6°C and lows of 7°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 84% — quite humid.
Average wind speed in August is 4.3 m/s. The windiest August on record averaged 5.4 m/s (1994).
The wettest August on record was 1982 with 147 mm. On average, August sees 89 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 Halfmoon Bay 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.
