October is one of the cooler months of the year in Halfmoon Bay, with average highs near 11.4°C and lows around 8°C (mean 9.7°C). It is about average for rainfall, averaging 110 mm of rainfall and 81% relative humidity across the period.
October is one of the cooler months of the year in Halfmoon Bay. Across 45 years of records, the warmest October in Halfmoon Bay was 1989 — when the month averaged 11.1°C — while the coldest was 2009 at 8.6°C. Typical October days reach 11.4°C with nights near 8°C. The long-term October temperature trend is broadly flat.
October is about average for rainfall in Halfmoon Bay, averaging 110 mm of rainfall. The wettest October on record was 2013 with 177 mm, while the driest was 2005 at 56 mm.
Relative humidity in Halfmoon Bay during October averages 81%. The most humid October was 2021 at 85%, and the least humid was 2018 at 78%.
October receives about 4.5 kWh/m²/day of solar energy in Halfmoon Bay. The sunniest October was 1985 at 5.2 kWh/m²/day, and the cloudiest were 2012 and 2019 at 4.
Average wind speed in Halfmoon Bay during October is 4.4 m/s. The windiest October was 2015 at 6.1 m/s, while the calmest was 1983 at 3.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 10.0°C | 9.6°C | 9.5°C | 9.8°C | 10.0°C | 0°C |
| Avg High | 11.7°C | 11.3°C | 11.1°C | 11.5°C | 11.7°C | 0°C |
| Avg Low | 8.4°C | 7.8°C | 7.8°C | 8.1°C | 8.2°C | -0.2°C |
| Avg Rain | 113 mm | 111 mm | 105 mm | 113 mm | 108 mm | -4 mm |
October temperatures in Halfmoon Bay have stayed relatively stable across the record.
October has ranged from a record low of 2.8°C (2003) to a record high of 17.5°C (2017).
Rainfall in October is about average for rainfall, averaging 110 mm, with a wettest year of 177 mm.
A good time to visit Halfmoon Bay
October is a good time to visit Halfmoon Bay, with days averaging 11.4°C and nights around 8°C (mean 9.7°C, close to Halfmoon Bay's yearly average) and higher rainfall. February and March are marginally more temperate, but October still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 11.4°C | 9.8°C | 8.2°C | 15.6°C | 4.9°C | 148 mm | 79% | 5.8 m/s | 4.4 |
| 2024 | 11.4°C | 9.8°C | 8.2°C | 15.2°C | 5.6°C | 135 mm | 84% | 4 m/s | 4.1 |
| 2023 | 11.8°C | 9.9°C | 8.0°C | 16.5°C | 4.5°C | 78 mm | 79% | 4.8 m/s | 4.6 |
| 2022 | 11.8°C | 9.9°C | 8.0°C | 17.4°C | 4.4°C | 82 mm | 79% | 3.9 m/s | 4.6 |
| 2021 | 12.0°C | 10.5°C | 8.9°C | 16.6°C | 6.0°C | 74 mm | 85% | 3.7 m/s | 4.6 |
| 2020 | 11.9°C | 10.0°C | 8.1°C | 16.4°C | 5.0°C | 131 mm | 80% | 4.1 m/s | 4.5 |
| 2019 | 10.5°C | 9.1°C | 7.6°C | 16.0°C | 5.7°C | 123 mm | 82% | 4.7 m/s | 4 |
| 2018 | 11.7°C | 9.9°C | 8.2°C | 16.3°C | 5.4°C | 73 mm | 78% | 4.2 m/s | 4.5 |
| 2017 | 12.2°C | 10.6°C | 9.0°C | 17.5°C | 6.2°C | 68 mm | 79% | 4.3 m/s | 5.1 |
| 2016 | 12.3°C | 10.5°C | 8.7°C | 15.1°C | 6.7°C | 110 mm | 82% | 3.6 m/s | 4.5 |
| 2015 | 11.2°C | 9.5°C | 7.8°C | 15.0°C | 5.5°C | 104 mm | 79% | 6.1 m/s | 4.5 |
| 2014 | 11.4°C | 9.5°C | 7.6°C | 16.2°C | 4.9°C | 144 mm | 80% | 4.7 m/s | 4.4 |
| 2013 🌧️ | 12.1°C | 10.2°C | 8.3°C | 16.2°C | 5.6°C | 177 mm | 80% | 5.1 m/s | 4.3 |
| 2012 | 10.3°C | 8.9°C | 7.5°C | 12.9°C | 5.4°C | 165 mm | 81% | 5.4 m/s | 4 |
| 2011 | 11.3°C | 9.5°C | 7.7°C | 15.9°C | 5.5°C | 88 mm | 82% | 3.9 m/s | 4.6 |
| 2010 | 11.9°C | 10.0°C | 8.2°C | 15.7°C | 5.7°C | 81 mm | 82% | 4.3 m/s | 4.9 |
| 2009 ❄️ | 10.1°C | 8.6°C | 7.1°C | 12.4°C | 5.0°C | 90 mm | 81% | 4.3 m/s | 4.2 |
| 2008 | 11.2°C | 9.6°C | 7.9°C | 15.7°C | 5.5°C | 136 mm | 79% | 5.3 m/s | 4.7 |
| 2007 | 10.6°C | 8.9°C | 7.2°C | 15.3°C | 4.8°C | 167 mm | 79% | 5 m/s | 4.4 |
| 2006 | 11.3°C | 9.5°C | 7.7°C | 15.3°C | 4.9°C | 88 mm | 79% | 5.2 m/s | 4.3 |
| 2005 | 11.3°C | 9.8°C | 8.2°C | 16.8°C | 6.1°C | 56 mm | 81% | 3.5 m/s | 4.6 |
| 2004 | 10.6°C | 8.9°C | 7.3°C | 14.6°C | 4.3°C | 84 mm | 80% | 4.3 m/s | 4.6 |
| 2003 | 11.2°C | 9.6°C | 8.0°C | 15.8°C | 2.8°C | 89 mm | 80% | 4.6 m/s | 4.7 |
| 2002 | 10.5°C | 8.8°C | 7.1°C | 13.9°C | 3.3°C | 147 mm | 82% | 4.2 m/s | 4.6 |
| 2001 | 12.3°C | 10.5°C | 8.8°C | 16.1°C | 6.4°C | 104 mm | 83% | 3.5 m/s | 4.2 |
| 2000 | 12.1°C | 10.3°C | 8.5°C | 16.0°C | 6.2°C | 93 mm | 80% | 4.6 m/s | 4.2 |
| 1999 | 12.7°C | 10.8°C | 8.9°C | 16.7°C | 5.1°C | 87 mm | 81% | 4.1 m/s | 4.5 |
| 1998 | 11.0°C | 9.5°C | 8.0°C | 16.6°C | 5.1°C | 101 mm | 83% | 4.8 m/s | 4.1 |
| 1997 | 11.6°C | 9.9°C | 8.1°C | 14.9°C | 4.4°C | 113 mm | 81% | 5.3 m/s | 4.5 |
| 1996 | 11.8°C | 10.0°C | 8.3°C | 15.6°C | 5.9°C | 143 mm | 81% | 4.4 m/s | 4.2 |
| 1995 | 10.6°C | 8.7°C | 6.9°C | 14.2°C | 4.5°C | 109 mm | 81% | 4.3 m/s | 4.4 |
| 1994 | 10.2°C | 8.7°C | 7.1°C | 14.0°C | 3.9°C | 87 mm | 82% | 4.7 m/s | 4.9 |
| 1993 | 12.1°C | 10.1°C | 8.1°C | 16.0°C | 5.7°C | 155 mm | 80% | 4.7 m/s | 4.6 |
| 1992 | 11.0°C | 9.3°C | 7.5°C | 14.4°C | 5.3°C | 60 mm | 80% | 3.7 m/s | 4.6 |
| 1991 | 11.2°C | 9.5°C | 7.8°C | 15.1°C | 6.0°C | 134 mm | 81% | 4.5 m/s | 4.6 |
| 1990 | 10.9°C | 9.3°C | 7.7°C | 14.7°C | 4.5°C | 124 mm | 81% | 4.4 m/s | 4.5 |
| 1989 🔥 | 12.8°C | 11.1°C | 9.5°C | 16.6°C | 5.7°C | 87 mm | 82% | 3.9 m/s | 4.6 |
| 1988 | 11.5°C | 9.8°C | 8.2°C | 14.1°C | 5.6°C | 138 mm | 82% | 5.2 m/s | 4.4 |
| 1987 | 11.7°C | 10.0°C | 8.3°C | 16.3°C | 4.9°C | 128 mm | 82% | 3.6 m/s | 4.5 |
| 1986 | 11.7°C | 10.3°C | 8.9°C | 14.8°C | 7.3°C | 112 mm | 83% | 3.8 m/s | 4.7 |
| 1985 | 11.6°C | 9.8°C | 8.0°C | 15.6°C | 5.1°C | 72 mm | 79% | 4.2 m/s | 5.2 |
| 1984 | 11.5°C | 9.9°C | 8.2°C | 14.0°C | 5.2°C | 108 mm | 80% | 4.2 m/s | 4.4 |
| 1983 | 11.8°C | 10.0°C | 8.2°C | 15.7°C | 5.5°C | 97 mm | 81% | 3.1 m/s | — |
| 1982 | 10.4°C | 8.9°C | 7.4°C | 13.6°C | 5.5°C | 158 mm | 80% | 4.9 m/s | — |
| 1981 | 12.4°C | 10.5°C | 8.7°C | 16.3°C | 5.4°C | 113 mm | 81% | 4.4 m/s | — |
Actual recorded October data for each year, 1981–2025 — sourced from NASA POWER.
The average high in October is around 11.4°C with lows near 8°C (mean 9.7°C), based on 45 years of NASA POWER data.
October averages 110 mm of rainfall in Halfmoon Bay, about average for rainfall. The wettest on record was 177 mm in 2013.
The hottest October reached 17.5°C in 2017. The coldest dipped to 2.8°C in 2003.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average October temperatures have risen by about 0.2°C. Daytime highs moved from 11.5°C to 11.7°C and overnight lows from 8.1°C to 8.3°C over the same span.
October is one of the cooler months of the year in Halfmoon Bay and about average for rainfall, so plan for around 11.4°C daytime highs and 8°C at night.
Not quite — October is the 5th coolest month in Halfmoon Bay, averaging 9.7°C.
For October in Halfmoon Bay, pack light layers you can adjust through the day, with typical highs of 11.4°C and lows of 8°C. Bring an umbrella or light rain jacket too.
Relative humidity in October averages 81% — quite humid.
Average wind speed in October is 4.4 m/s. The windiest October on record averaged 6.1 m/s (2015).
The wettest October on record was 2013 with 177 mm. On average, October sees 110 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 October, 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 October specifically, along with year-by-year records and how the month has changed over the decades.
