December is one of the warmer months of the year in Hamilton, with average highs near 20.9°C and lows around 13.6°C (mean 17.3°C). It is about average for rainfall, averaging 96 mm of rainfall and 78% relative humidity across the period.
December is one of the warmer months of the year in Hamilton. Across 45 years of records, the warmest December in Hamilton was 2021 — when the month averaged 19.5°C — while the coldest was 2006 at 14.5°C. Typical December days reach 20.9°C with nights near 13.6°C. The long-term trend is warming, about 0.3°C per decade.
December is about average for rainfall in Hamilton, averaging 96 mm of rainfall. The wettest December on record was 2011 with 221 mm, while the driest was 2017 at 28 mm.
Relative humidity in Hamilton during December averages 78%. The most humid December was 2023 at 82%, and the least humid was 1986 at 74%.
December receives about 6.2 kWh/m²/day of solar energy in Hamilton. The sunniest December was 2017 at 7.3 kWh/m²/day, and the cloudiest was 2011 at 5.
Average wind speed in Hamilton during December is 4.1 m/s. The windiest December was 2004 at 5.6 m/s, while the calmest were 1986, 2017 and 2022, among others at 3.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 17.3°C | 16.7°C | 16.9°C | 17.7°C | 18.2°C | +0.9°C |
| Avg High | 21.0°C | 20.4°C | 20.3°C | 21.4°C | 21.9°C | +0.9°C |
| Avg Low | 13.6°C | 13.0°C | 13.4°C | 14.0°C | 14.6°C | +1°C |
| Avg Rain | 109 mm | 78 mm | 101 mm | 93 mm | 102 mm | -7 mm |
December temperatures in Hamilton have risen by about 1.1°C between 1981–1985 and 2021–2025.
December has ranged from a record low of 5.3°C (1992) to a record high of 27.2°C (2017).
Rainfall in December is about average for rainfall, averaging 96 mm, with a wettest year of 221 mm.
One of the best times to visit Hamilton
December is one of the best times to visit Hamilton. Expect days averaging 20.9°C and nights around 13.6°C (mean 17.3°C) — warmer than Hamilton's yearly average — with higher rainfall (96 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 22.1°C | 18.3°C | 14.6°C | 27.0°C | 12.1°C | 105 mm | 77% | 4.2 m/s | — |
| 2024 | 22.1°C | 18.2°C | 14.3°C | 25.5°C | 9.7°C | 74 mm | 80% | 4 m/s | 6.9 |
| 2023 | 21.4°C | 18.2°C | 14.9°C | 25.1°C | 11.5°C | 137 mm | 82% | 3.7 m/s | 5.7 |
| 2022 | 22.0°C | 18.4°C | 14.8°C | 26.2°C | 10.2°C | 126 mm | 79% | 3.4 m/s | 6.5 |
| 2021 🔥 | 22.8°C | 19.5°C | 16.2°C | 26.1°C | 13.5°C | 120 mm | 80% | 4 m/s | 6.2 |
| 2020 | 20.9°C | 16.8°C | 12.7°C | 24.2°C | 8.2°C | 49 mm | 77% | 4.3 m/s | 7 |
| 2019 | 21.8°C | 17.7°C | 13.6°C | 24.9°C | 9.2°C | 83 mm | 77% | 4.2 m/s | 6.9 |
| 2018 | 21.6°C | 18.2°C | 14.7°C | 24.8°C | 8.8°C | 144 mm | 79% | 3.7 m/s | 6.1 |
| 2017 | 23.2°C | 19.2°C | 15.2°C | 27.2°C | 10.5°C | 28 mm | 74% | 3.4 m/s | 7.3 |
| 2016 | 20.1°C | 16.3°C | 12.5°C | 24.0°C | 9.6°C | 50 mm | 78% | 4 m/s | 6.4 |
| 2015 | 20.5°C | 16.8°C | 13.0°C | 25.8°C | 9.9°C | 32 mm | 77% | 4.2 m/s | 6.8 |
| 2014 | 20.9°C | 17.1°C | 13.2°C | 24.6°C | 6.7°C | 82 mm | 78% | 3.8 m/s | 5.9 |
| 2013 | 21.0°C | 17.4°C | 13.8°C | 24.6°C | 10.7°C | 113 mm | 76% | 4 m/s | 6.4 |
| 2012 | 22.0°C | 18.3°C | 14.5°C | 26.5°C | 8.3°C | 74 mm | 79% | 3.7 m/s | 5.8 |
| 2011 🌧️ | 20.8°C | 17.4°C | 14.1°C | 23.5°C | 9.3°C | 221 mm | 80% | 4 m/s | 5 |
| 2010 | 22.0°C | 18.6°C | 15.1°C | 25.5°C | 12.3°C | 100 mm | 79% | 3.8 m/s | 5.4 |
| 2009 | 20.1°C | 16.3°C | 12.5°C | 23.1°C | 9.7°C | 86 mm | 78% | 4.2 m/s | 6.4 |
| 2008 | 21.1°C | 17.4°C | 13.6°C | 24.8°C | 9.9°C | 93 mm | 78% | 3.9 m/s | 6 |
| 2007 | 21.7°C | 17.8°C | 13.9°C | 26.0°C | 11.1°C | 71 mm | 77% | 3.7 m/s | 5.8 |
| 2006 ❄️ | 18.1°C | 14.5°C | 10.9°C | 20.9°C | 5.9°C | 69 mm | 77% | 4.3 m/s | 6.4 |
| 2005 | 21.1°C | 17.9°C | 14.7°C | 25.0°C | 11.2°C | 125 mm | 82% | 4.3 m/s | 5.8 |
| 2004 | 17.5°C | 14.6°C | 11.6°C | 22.9°C | 7.9°C | 114 mm | 78% | 5.6 m/s | 5.6 |
| 2003 | 21.0°C | 17.4°C | 13.9°C | 25.1°C | 9.6°C | 117 mm | 80% | 3.9 m/s | 5.8 |
| 2002 | 20.1°C | 16.7°C | 13.4°C | 22.9°C | 9.8°C | 100 mm | 78% | 4.2 m/s | 6.1 |
| 2001 | 21.2°C | 18.2°C | 15.2°C | 23.9°C | 12.7°C | 186 mm | 81% | 4.5 m/s | 5.1 |
| 2000 | 21.3°C | 17.9°C | 14.5°C | 24.5°C | 11.9°C | 44 mm | 78% | 3.7 m/s | 5.9 |
| 1999 | 20.1°C | 16.4°C | 12.7°C | 23.0°C | 8.2°C | 34 mm | 76% | 4.2 m/s | 6.2 |
| 1998 | 21.4°C | 17.7°C | 14.0°C | 25.8°C | 10.9°C | 67 mm | 77% | 4 m/s | 6.2 |
| 1997 | 20.5°C | 16.6°C | 12.8°C | 24.1°C | 9.6°C | 61 mm | 77% | 3.7 m/s | 6.3 |
| 1996 | 19.7°C | 16.0°C | 12.3°C | 24.1°C | 8.3°C | 158 mm | 78% | 4.3 m/s | 5.9 |
| 1995 | 21.5°C | 18.0°C | 14.4°C | 26.4°C | 11.7°C | 109 mm | 80% | 4.4 m/s | 6.1 |
| 1994 | 21.1°C | 17.2°C | 13.3°C | 24.9°C | 9.5°C | 48 mm | 76% | 3.9 m/s | 6.6 |
| 1993 | 19.5°C | 15.8°C | 12.1°C | 24.6°C | 9.0°C | 59 mm | 77% | 4.2 m/s | 5.9 |
| 1992 | 19.9°C | 16.3°C | 12.6°C | 22.6°C | 5.3°C | 145 mm | 79% | 4.3 m/s | 5.7 |
| 1991 | 19.4°C | 15.8°C | 12.1°C | 23.9°C | 7.1°C | 70 mm | 79% | 4 m/s | 6.4 |
| 1990 | 20.7°C | 17.0°C | 13.3°C | 24.4°C | 11.0°C | 31 mm | 77% | 4.8 m/s | 6.4 |
| 1989 | 20.3°C | 16.4°C | 12.6°C | 23.3°C | 7.8°C | 100 mm | 76% | 4.6 m/s | 6.5 |
| 1988 | 22.1°C | 18.4°C | 14.6°C | 24.8°C | 12.0°C | 118 mm | 77% | 3.7 m/s | 6.1 |
| 1987 | 20.3°C | 16.9°C | 13.6°C | 24.6°C | 10.5°C | 151 mm | 79% | 4.4 m/s | 6.1 |
| 1986 | 21.0°C | 17.0°C | 12.9°C | 24.5°C | 7.8°C | 86 mm | 74% | 3.4 m/s | 6.5 |
| 1985 | 21.6°C | 18.0°C | 14.3°C | 24.5°C | 10.9°C | 115 mm | 78% | 3.4 m/s | 6.4 |
| 1984 | 22.7°C | 18.8°C | 14.9°C | 26.2°C | 12.0°C | 139 mm | 78% | 3.7 m/s | 6.2 |
| 1983 | 19.5°C | 16.0°C | 12.5°C | 24.0°C | 8.8°C | 110 mm | 76% | 4.8 m/s | — |
| 1982 | 19.5°C | 15.9°C | 12.2°C | 22.3°C | 7.0°C | 77 mm | 77% | 4.7 m/s | — |
| 1981 | 22.0°C | 18.4°C | 14.8°C | 26.6°C | 11.8°C | 84 mm | 79% | 3.6 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 20.9°C with lows near 13.6°C (mean 17.3°C), based on 45 years of NASA POWER data.
December averages 96 mm of rainfall in Hamilton, about average for rainfall. The wettest on record was 221 mm in 2011.
The hottest December reached 27.2°C in 2017. The coldest dipped to 5.3°C in 1992.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 1.1°C. Daytime highs moved from 21.1°C to 22.1°C and overnight lows from 13.7°C to 15°C over the same span.
December is one of the warmer months of the year in Hamilton and about average for rainfall, so plan for around 20.9°C daytime highs and 13.6°C at night.
Not quite — December is the 9th coolest month in Hamilton, averaging 17.3°C.
For December in Hamilton, pack light layers you can adjust through the day, with typical highs of 20.9°C and lows of 13.6°C. Bring an umbrella or light rain jacket too.
Relative humidity in December averages 78% — quite humid.
Average wind speed in December is 4.1 m/s. The windiest December on record averaged 5.6 m/s (2004).
The wettest December on record was 2011 with 221 mm. On average, December sees 96 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 December, 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 December specifically, along with year-by-year records and how the month has changed over the decades.
