December is one of the warmer months of the year in Hamilton, with average highs near 25.7°C and lows around 10.3°C (mean 18°C). It is about average for rainfall, averaging 42 mm of rainfall and 60% 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 2015 — when the month averaged 21.4°C — while the coldest was 2001 at 14.3°C. Typical December days reach 25.7°C with nights near 10.3°C. The long-term trend is warming, about 0.3°C per decade.
December is about average for rainfall in Hamilton, averaging 42 mm of rainfall. The wettest December on record was 2010 with 137 mm, while the driest was 1997 at 7 mm.
Relative humidity in Hamilton during December averages 60%. The most humid December was 1992 at 77%, and the least humid was 2015 at 46%.
December receives about 7.1 kWh/m²/day of solar energy in Hamilton. The sunniest December was 2021 at 8 kWh/m²/day, and the cloudiest was 1992 at 5.8.
Average wind speed in Hamilton during December is 3.4 m/s. The windiest December was 2005 at 3.9 m/s, while the calmest were 1983 and 2022 at 3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 17.6°C | 17.7°C | 18.0°C | 18.9°C | 17.8°C | +0.2°C |
| Avg High | 25.3°C | 25.2°C | 25.8°C | 26.8°C | 25.4°C | +0.1°C |
| Avg Low | 10.0°C | 10.1°C | 10.2°C | 10.9°C | 10.1°C | +0.1°C |
| Avg Rain | 47 mm | 38 mm | 44 mm | 39 mm | 40 mm | -6 mm |
December temperatures in Hamilton have risen by about 0.3°C between 1981–1985 and 2021–2025.
December has ranged from a record low of 3.2°C (1994) to a record high of 45.4°C (2019).
Rainfall in December is about average for rainfall, averaging 42 mm, with a wettest year of 137 mm.
One of the best times to visit Hamilton
December is one of the best times to visit Hamilton. Expect days averaging 25.7°C and nights around 10.3°C (mean 18°C) — warmer than Hamilton's yearly average — with moderate rainfall (42 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 | 25.9°C | 17.8°C | 9.6°C | 38.9°C | 5.7°C | 27 mm | 55% | 3.3 m/s | — |
| 2024 | 27.1°C | 19.0°C | 11.0°C | 40.4°C | 7.6°C | 42 mm | 60% | 3.2 m/s | 7.5 |
| 2023 | 24.8°C | 18.0°C | 11.1°C | 35.8°C | 8.6°C | 82 mm | 68% | 3.6 m/s | 6.3 |
| 2022 | 24.3°C | 17.0°C | 9.7°C | 38.6°C | 5.1°C | 34 mm | 65% | 3 m/s | 7.3 |
| 2021 | 27.0°C | 18.7°C | 10.4°C | 38.8°C | 7.0°C | 9 mm | 55% | 3.5 m/s | 8 |
| 2020 | 23.1°C | 16.0°C | 8.8°C | 34.8°C | 5.1°C | 48 mm | 63% | 3.5 m/s | 6.8 |
| 2019 | 28.6°C | 19.9°C | 11.1°C | 45.4°C | 5.7°C | 12 mm | 53% | 3.6 m/s | 7.9 |
| 2018 | 28.4°C | 20.4°C | 12.5°C | 39.4°C | 7.6°C | 52 mm | 59% | 3.2 m/s | 6.7 |
| 2017 | 26.5°C | 18.9°C | 11.2°C | 38.4°C | 6.8°C | 26 mm | 59% | 3.2 m/s | 7.1 |
| 2016 | 27.0°C | 18.9°C | 10.7°C | 38.1°C | 6.5°C | 30 mm | 56% | 3.2 m/s | 7.3 |
| 2015 🔥 | 30.4°C | 21.4°C | 12.3°C | 42.6°C | 5.9°C | 26 mm | 46% | 3.3 m/s | 7.7 |
| 2014 | 26.3°C | 18.6°C | 10.9°C | 34.1°C | 6.6°C | 21 mm | 59% | 3.2 m/s | 7.1 |
| 2013 | 25.7°C | 17.7°C | 9.7°C | 39.8°C | 4.9°C | 27 mm | 61% | 3.2 m/s | 7.3 |
| 2012 | 26.1°C | 18.3°C | 10.4°C | 36.2°C | 7.0°C | 25 mm | 57% | 3.3 m/s | 7.3 |
| 2011 | 26.5°C | 18.4°C | 10.3°C | 36.6°C | 4.9°C | 37 mm | 61% | 3.2 m/s | 7.5 |
| 2010 🌧️ | 22.4°C | 16.2°C | 9.9°C | 35.8°C | 4.6°C | 137 mm | 72% | 3.1 m/s | 6.7 |
| 2009 | 26.3°C | 18.0°C | 9.6°C | 38.0°C | 6.3°C | 42 mm | 59% | 3.1 m/s | 7.5 |
| 2008 | 22.6°C | 16.1°C | 9.5°C | 29.4°C | 5.8°C | 100 mm | 67% | 3.3 m/s | 6.7 |
| 2007 | 27.2°C | 19.1°C | 11.0°C | 40.5°C | 5.4°C | 56 mm | 59% | 3.1 m/s | 7.2 |
| 2006 | 26.6°C | 18.2°C | 9.7°C | 41.7°C | 5.6°C | 17 mm | 49% | 3.5 m/s | 7.8 |
| 2005 | 27.2°C | 19.0°C | 10.9°C | 42.9°C | 6.8°C | 37 mm | 55% | 3.9 m/s | 7.1 |
| 2004 | 25.9°C | 18.6°C | 11.2°C | 38.1°C | 6.6°C | 41 mm | 62% | 3.2 m/s | 7.1 |
| 2003 | 28.3°C | 19.9°C | 11.6°C | 39.1°C | 7.0°C | 42 mm | 56% | 3.4 m/s | 7.2 |
| 2002 | 26.3°C | 18.3°C | 10.3°C | 38.0°C | 5.8°C | 42 mm | 58% | 3.8 m/s | 7.2 |
| 2001 ❄️ | 20.7°C | 14.3°C | 8.0°C | 32.7°C | 5.6°C | 45 mm | 72% | 3.3 m/s | 5.9 |
| 2000 | 27.1°C | 18.7°C | 10.3°C | 38.9°C | 6.8°C | 22 mm | 55% | 3.3 m/s | 7.7 |
| 1999 | 24.8°C | 17.8°C | 10.8°C | 35.4°C | 5.6°C | 61 mm | 61% | 3.7 m/s | 7 |
| 1998 | 26.8°C | 18.9°C | 11.0°C | 41.3°C | 7.3°C | 20 mm | 58% | 3.4 m/s | 7 |
| 1997 | 26.2°C | 18.3°C | 10.5°C | 34.9°C | 7.4°C | 7 mm | 60% | 3.5 m/s | 7.4 |
| 1996 | 24.0°C | 16.2°C | 8.3°C | 34.2°C | 5.6°C | 30 mm | 59% | 3.2 m/s | 7.1 |
| 1995 | 23.3°C | 15.8°C | 8.4°C | 31.7°C | 4.1°C | 34 mm | 63% | 3.7 m/s | 7 |
| 1994 | 28.6°C | 19.9°C | 11.1°C | 37.6°C | 3.2°C | 18 mm | 51% | 3.3 m/s | 7.9 |
| 1993 | 23.9°C | 16.5°C | 9.1°C | 33.1°C | 4.3°C | 72 mm | 64% | 3.5 m/s | 7 |
| 1992 | 23.2°C | 17.2°C | 11.2°C | 32.0°C | 5.6°C | 76 mm | 77% | 3.2 m/s | 5.8 |
| 1991 | 24.5°C | 17.1°C | 9.7°C | 37.5°C | 5.0°C | 38 mm | 63% | 3.3 m/s | 7 |
| 1990 | 27.0°C | 19.0°C | 10.9°C | 36.6°C | 7.2°C | 27 mm | 59% | 3.4 m/s | 7.1 |
| 1989 | 26.7°C | 18.7°C | 10.6°C | 36.4°C | 5.9°C | 19 mm | 56% | 3.5 m/s | 7.3 |
| 1988 | 26.7°C | 18.6°C | 10.6°C | 37.0°C | 6.0°C | 31 mm | 62% | 3.2 m/s | 6.9 |
| 1987 | 24.7°C | 16.9°C | 9.2°C | 34.6°C | 4.2°C | 75 mm | 61% | 3.4 m/s | 7.1 |
| 1986 | 22.2°C | 15.4°C | 8.5°C | 35.7°C | 3.6°C | 100 mm | 68% | 3.4 m/s | 6.4 |
| 1985 | 22.8°C | 16.5°C | 10.2°C | 29.8°C | 7.3°C | 108 mm | 69% | 3.4 m/s | 6 |
| 1984 | 24.7°C | 17.0°C | 9.4°C | 34.0°C | 6.2°C | 33 mm | 61% | 3.8 m/s | 6.9 |
| 1983 | 26.2°C | 18.3°C | 10.4°C | 38.2°C | 5.1°C | 22 mm | 61% | 3 m/s | — |
| 1982 | 27.1°C | 18.8°C | 10.5°C | 36.2°C | 6.3°C | 20 mm | 52% | 3.4 m/s | — |
| 1981 | 26.3°C | 18.2°C | 10.2°C | 38.7°C | 6.7°C | 13 mm | 56% | 3.5 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 25.7°C with lows near 10.3°C (mean 18°C), based on 45 years of NASA POWER data.
December averages 42 mm of rainfall in Hamilton, about average for rainfall. The wettest on record was 137 mm in 2010.
The hottest December reached 45.4°C in 2019. The coldest dipped to 3.2°C in 1994.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 0.3°C. Daytime highs moved from 25.4°C to 25.8°C and overnight lows from 10.1°C to 10.4°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 25.7°C daytime highs and 10.3°C at night.
Not quite — December is the 9th coolest month in Hamilton, averaging 18°C.
For December in Hamilton, pack light layers you can adjust through the day, with typical highs of 25.7°C and lows of 10.3°C.
Relative humidity in December averages 60% — moderately humid.
Average wind speed in December is 3.4 m/s. The windiest December on record averaged 3.9 m/s (2005).
The wettest December on record was 2010 with 137 mm. On average, December sees 42 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.
