April is one of the warmer months of the year in Halfmoon Bay, with average highs near 13°C and lows around 10°C (mean 11.5°C). It is about average for rainfall, averaging 103 mm of rainfall and 83% relative humidity across the period.
April is one of the warmer months of the year in Halfmoon Bay. Across 45 years of records, the warmest Aprils in Halfmoon Bay were 2016 and 2023 — when the month averaged 12.8°C — while the coldest was 1983 at 9.9°C. Typical April days reach 13°C with nights near 10°C. The long-term trend is warming, about 0.2°C per decade.
April is about average for rainfall in Halfmoon Bay, averaging 103 mm of rainfall. The wettest April on record was 2010 with 167 mm, while the driest was 1982 at 17 mm.
Relative humidity in Halfmoon Bay during April averages 83%. The most humid April was 2006 at 86%, and the least humid was 2018 at 79%.
April receives about 2.4 kWh/m²/day of solar energy in Halfmoon Bay. The sunniest April was 1986 at 2.7 kWh/m²/day, and the cloudiest were 1997 and 2010 at 2.
Average wind speed in Halfmoon Bay during April is 4.2 m/s. The windiest April was 2018 at 5.4 m/s, while the calmest was 1982 at 3.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 11.4°C | 11.1°C | 11.4°C | 11.7°C | 12.2°C | +0.8°C |
| Avg High | 12.9°C | 12.5°C | 12.9°C | 13.3°C | 13.7°C | +0.8°C |
| Avg Low | 9.9°C | 9.6°C | 9.9°C | 10.2°C | 10.7°C | +0.8°C |
| Avg Rain | 106 mm | 112 mm | 89 mm | 110 mm | 92 mm | -15 mm |
April temperatures in Halfmoon Bay have risen by about 0.9°C between 1981–1985 and 2021–2025.
April has ranged from a record low of 5.1°C (1985) to a record high of 19.3°C (2025).
Rainfall in April is about average for rainfall, averaging 103 mm, with a wettest year of 167 mm.
A good time to visit Halfmoon Bay
April is a good time to visit Halfmoon Bay, with days averaging 13°C and nights around 10°C (mean 11.5°C, close to Halfmoon Bay's yearly average) and higher rainfall. February and March are marginally more temperate, but April still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 14.2°C | 12.4°C | 10.7°C | 19.3°C | 7.9°C | 68 mm | 82% | 4 m/s | 2.5 |
| 2024 | 13.1°C | 11.5°C | 9.8°C | 17.4°C | 6.8°C | 119 mm | 83% | 4.2 m/s | 2.2 |
| 2023 | 14.3°C | 12.8°C | 11.3°C | 16.8°C | 9.0°C | 67 mm | 84% | 4.4 m/s | 2.6 |
| 2022 | 13.8°C | 12.4°C | 11.0°C | 16.6°C | 8.3°C | 95 mm | 80% | 4.6 m/s | 2.5 |
| 2021 | 13.7°C | 12.3°C | 10.8°C | 16.3°C | 7.6°C | 87 mm | 81% | 4.9 m/s | 2.4 |
| 2020 | 13.2°C | 11.8°C | 10.4°C | 18.3°C | 7.3°C | 113 mm | 84% | 4.5 m/s | 2.3 |
| 2019 | 13.7°C | 12.0°C | 10.2°C | 18.3°C | 8.3°C | 84 mm | 80% | 3.6 m/s | 2.6 |
| 2018 | 12.8°C | 11.5°C | 10.1°C | 17.6°C | 7.1°C | 136 mm | 79% | 5.4 m/s | 2.2 |
| 2017 | 13.2°C | 11.7°C | 10.2°C | 18.0°C | 7.4°C | 87 mm | 84% | 3.8 m/s | 2.3 |
| 2016 🔥 | 14.5°C | 12.8°C | 11.1°C | 17.0°C | 8.6°C | 144 mm | 83% | 4.8 m/s | 2.3 |
| 2015 | 13.1°C | 11.4°C | 9.7°C | 18.4°C | 5.6°C | 110 mm | 82% | 4.1 m/s | 2.1 |
| 2014 | 13.0°C | 11.5°C | 10.0°C | 17.9°C | 7.9°C | 93 mm | 83% | 4 m/s | 2.3 |
| 2013 | 13.1°C | 11.6°C | 10.1°C | 17.4°C | 6.1°C | 119 mm | 81% | 4.5 m/s | 2.3 |
| 2012 | 14.0°C | 12.3°C | 10.6°C | 16.5°C | 6.8°C | 63 mm | 85% | 3.5 m/s | 2.5 |
| 2011 | 12.2°C | 10.8°C | 9.5°C | 16.0°C | 6.5°C | 102 mm | 83% | 4.1 m/s | 2.3 |
| 2010 🌧️ | 13.0°C | 11.5°C | 10.0°C | 16.0°C | 7.3°C | 167 mm | 84% | 4.6 m/s | 2 |
| 2009 | 13.6°C | 11.9°C | 10.2°C | 17.7°C | 6.6°C | 66 mm | 81% | 3.6 m/s | 2.6 |
| 2008 | 13.4°C | 11.7°C | 10.1°C | 16.1°C | 6.9°C | 63 mm | 82% | 3.9 m/s | 2.3 |
| 2007 | 11.9°C | 10.6°C | 9.3°C | 14.7°C | 5.8°C | 62 mm | 84% | 4 m/s | 2.2 |
| 2006 | 13.8°C | 12.4°C | 11.0°C | 17.5°C | 7.3°C | 117 mm | 86% | 3.7 m/s | 2.4 |
| 2005 | 13.0°C | 11.1°C | 9.2°C | 17.4°C | 5.8°C | 86 mm | 80% | 4.8 m/s | 2.5 |
| 2004 | 11.5°C | 10.1°C | 8.7°C | 15.8°C | 6.0°C | 122 mm | 86% | 4 m/s | 2.3 |
| 2003 | 11.9°C | 10.6°C | 9.3°C | 15.2°C | 7.3°C | 85 mm | 83% | 3.9 m/s | 2.2 |
| 2002 | 12.9°C | 11.4°C | 9.9°C | 17.0°C | 7.4°C | 99 mm | 85% | 4 m/s | 2.2 |
| 2001 | 13.9°C | 12.2°C | 10.5°C | 17.2°C | 7.7°C | 104 mm | 82% | 4.5 m/s | 2.3 |
| 2000 | 13.2°C | 11.8°C | 10.3°C | 16.5°C | 8.4°C | 88 mm | 81% | 4.7 m/s | 2.3 |
| 1999 | 13.1°C | 11.4°C | 9.8°C | 17.0°C | 6.1°C | 84 mm | 81% | 4 m/s | 2.4 |
| 1998 | 12.5°C | 10.8°C | 9.0°C | 15.4°C | 6.6°C | 116 mm | 81% | 4.8 m/s | 2.2 |
| 1997 | 12.4°C | 10.8°C | 9.2°C | 17.1°C | 6.2°C | 160 mm | 82% | 4.9 m/s | 2 |
| 1996 | 12.7°C | 11.4°C | 10.1°C | 15.7°C | 7.1°C | 141 mm | 86% | 3.6 m/s | 2.1 |
| 1995 | 12.8°C | 11.3°C | 9.8°C | 16.7°C | 6.5°C | 42 mm | 83% | 3.3 m/s | 2.6 |
| 1994 | 13.6°C | 12.1°C | 10.6°C | 16.0°C | 7.1°C | 164 mm | 82% | 4.9 m/s | 2.5 |
| 1993 | 12.0°C | 10.6°C | 9.2°C | 15.3°C | 6.6°C | 79 mm | 84% | 3.8 m/s | 2.5 |
| 1992 | 11.7°C | 10.3°C | 8.9°C | 15.4°C | 6.9°C | 74 mm | 81% | 4 m/s | 2.5 |
| 1991 | 11.8°C | 10.4°C | 9.0°C | 16.9°C | 7.0°C | 126 mm | 82% | 4.1 m/s | 2.3 |
| 1990 | 12.8°C | 11.4°C | 10.0°C | 18.1°C | 5.4°C | 130 mm | 83% | 4.9 m/s | 2.3 |
| 1989 | 12.9°C | 11.6°C | 10.3°C | 15.4°C | 7.0°C | 77 mm | 83% | 4.7 m/s | 2.5 |
| 1988 | 12.0°C | 10.4°C | 8.8°C | 15.3°C | 6.4°C | 66 mm | 81% | 4.2 m/s | 2.4 |
| 1987 | 12.6°C | 11.1°C | 9.7°C | 16.0°C | 7.1°C | 135 mm | 82% | 4.8 m/s | 2.4 |
| 1986 | 14.1°C | 12.6°C | 11.2°C | 18.1°C | 8.6°C | 165 mm | 83% | 4.7 m/s | 2.7 |
| 1985 | 13.6°C | 12.0°C | 10.5°C | 16.9°C | 5.1°C | 139 mm | 84% | 3.2 m/s | 2.6 |
| 1984 | 13.1°C | 11.7°C | 10.3°C | 15.6°C | 7.2°C | 132 mm | 83% | 4.7 m/s | 2.3 |
| 1983 ❄️ | 11.3°C | 9.9°C | 8.4°C | 15.6°C | 5.9°C | 94 mm | 85% | 3.8 m/s | — |
| 1982 | 12.9°C | 11.2°C | 9.6°C | 15.8°C | 7.3°C | 17 mm | 82% | 3.1 m/s | — |
| 1981 | 13.6°C | 12.1°C | 10.7°C | 15.8°C | 8.3°C | 132 mm | 84% | 4.2 m/s | — |
Actual recorded April data for each year, 1981–2025 — sourced from NASA POWER.
The average high in April is around 13°C with lows near 10°C (mean 11.5°C), based on 45 years of NASA POWER data.
April averages 103 mm of rainfall in Halfmoon Bay, about average for rainfall. The wettest on record was 167 mm in 2010.
The hottest April reached 19.3°C in 2025. The coldest dipped to 5.1°C in 1985.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average April temperatures have risen by about 0.9°C. Daytime highs moved from 12.9°C to 13.8°C and overnight lows from 9.9°C to 10.7°C over the same span.
April is one of the warmer months of the year in Halfmoon Bay and about average for rainfall, so plan for around 13°C daytime highs and 10°C at night.
Not quite — April is the 8th coolest month in Halfmoon Bay, averaging 11.5°C.
For April in Halfmoon Bay, pack light layers you can adjust through the day, with typical highs of 13°C and lows of 10°C. Bring an umbrella or light rain jacket too.
Relative humidity in April averages 83% — quite humid.
Average wind speed in April is 4.2 m/s. The windiest April on record averaged 5.4 m/s (2018).
The wettest April on record was 2010 with 167 mm. On average, April sees 103 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 April, 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 April specifically, along with year-by-year records and how the month has changed over the decades.
