January is one of the warmer months of the year in Hamilton, with average highs near 22.8°C and lows around 14.9°C (mean 18.9°C). It is one of the drier months, averaging 75 mm of rainfall and 76% relative humidity across the period.
January is one of the warmer months of the year in Hamilton. Across 45 years of records, the warmest January in Hamilton was 2018 — when the month averaged 21.4°C — while the coldest was 1983 at 16.8°C. Typical January days reach 22.8°C with nights near 14.9°C. The long-term trend is warming, about 0.2°C per decade.
January is one of the drier months in Hamilton, averaging 75 mm of rainfall. The wettest January on record was 2023 with 262 mm, while the driest was 1988 at 12 mm.
Relative humidity in Hamilton during January averages 76%. The most humid January was 2018 at 80%, and the least humid was 2013 at 72%.
January receives about 6.4 kWh/m²/day of solar energy in Hamilton. The sunniest January was 2022 at 7.6 kWh/m²/day, and the cloudiest was 2023 at 5.
Average wind speed in Hamilton during January is 3.8 m/s. The windiest January was 1983 at 5 m/s, while the calmest was 2015 at 2.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 18.9°C | 18.6°C | 18.7°C | 19.0°C | 19.3°C | +0.4°C |
| Avg High | 22.9°C | 22.6°C | 22.7°C | 22.9°C | 23.2°C | +0.3°C |
| Avg Low | 14.9°C | 14.7°C | 14.7°C | 15.1°C | 15.3°C | +0.4°C |
| Avg Rain | 92 mm | 70 mm | 61 mm | 77 mm | 79 mm | -14 mm |
January temperatures in Hamilton have risen by about 0.9°C between 1981–1985 and 2021–2025.
January has ranged from a record low of 8.1°C (1997) to a record high of 29.5°C (2018).
Rainfall in January is one of the drier months, averaging 75 mm, with a wettest year of 262 mm.
One of the best times to visit Hamilton
January is one of the best times to visit Hamilton. Expect days averaging 22.8°C and nights around 14.9°C (mean 18.9°C) — warmer than Hamilton's yearly average — with moderate rainfall (75 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 | 22.4°C | 18.2°C | 14.1°C | 25.4°C | 10.6°C | 45 mm | 74% | 4.1 m/s | 6.4 |
| 2024 | 24.5°C | 20.5°C | 16.4°C | 28.4°C | 11.8°C | 76 mm | 77% | 3.3 m/s | 6.3 |
| 2023 🌧️ | 22.7°C | 19.5°C | 16.3°C | 25.8°C | 13.5°C | 262 mm | 80% | 4.2 m/s | 5 |
| 2022 | 24.7°C | 20.2°C | 15.8°C | 27.6°C | 13.3°C | 15 mm | 73% | 3.3 m/s | 7.6 |
| 2021 | 22.7°C | 18.9°C | 15.1°C | 26.2°C | 11.7°C | 58 mm | 76% | 3.7 m/s | 7 |
| 2020 | 22.3°C | 18.3°C | 14.3°C | 26.5°C | 11.5°C | 19 mm | 76% | 3.8 m/s | 7.2 |
| 2019 | 23.8°C | 19.8°C | 15.9°C | 29.1°C | 13.3°C | 36 mm | 79% | 4 m/s | 7.1 |
| 2018 🔥 | 25.0°C | 21.4°C | 17.7°C | 29.5°C | 15.1°C | 125 mm | 80% | 3.6 m/s | 5.9 |
| 2017 | 20.7°C | 17.3°C | 13.9°C | 23.6°C | 9.0°C | 52 mm | 78% | 4.8 m/s | 6.5 |
| 2016 | 24.0°C | 20.0°C | 15.9°C | 28.1°C | 12.1°C | 92 mm | 77% | 3.5 m/s | 6.2 |
| 2015 | 24.3°C | 20.0°C | 15.6°C | 27.3°C | 13.0°C | 26 mm | 74% | 2.9 m/s | 7.2 |
| 2014 | 21.3°C | 17.3°C | 13.3°C | 25.6°C | 9.4°C | 54 mm | 75% | 4.6 m/s | 6.8 |
| 2013 | 23.0°C | 18.6°C | 14.2°C | 27.3°C | 10.9°C | 19 mm | 72% | 3.8 m/s | 6.9 |
| 2012 | 20.9°C | 17.5°C | 14.2°C | 23.7°C | 9.7°C | 77 mm | 79% | 4.2 m/s | 5.7 |
| 2011 | 24.0°C | 19.7°C | 15.5°C | 27.4°C | 13.1°C | 200 mm | 75% | 3.9 m/s | 6.3 |
| 2010 | 22.2°C | 18.3°C | 14.3°C | 26.2°C | 9.6°C | 89 mm | 76% | 3.7 m/s | 6.4 |
| 2009 | 22.8°C | 18.6°C | 14.4°C | 27.1°C | 11.7°C | 38 mm | 74% | 3.7 m/s | 7 |
| 2008 | 24.9°C | 20.3°C | 15.8°C | 27.8°C | 13.1°C | 29 mm | 73% | 3.4 m/s | 6.8 |
| 2007 | 21.6°C | 18.0°C | 14.5°C | 24.8°C | 8.7°C | 88 mm | 80% | 3.9 m/s | 5.9 |
| 2006 | 22.7°C | 18.9°C | 15.1°C | 28.1°C | 11.2°C | 92 mm | 76% | 4.1 m/s | 5.9 |
| 2005 | 22.2°C | 18.2°C | 14.2°C | 27.6°C | 10.9°C | 35 mm | 77% | 3.5 m/s | 6.8 |
| 2004 | 23.5°C | 19.3°C | 15.2°C | 26.4°C | 11.5°C | 67 mm | 78% | 3.2 m/s | 6.4 |
| 2003 | 22.2°C | 18.2°C | 14.1°C | 25.7°C | 8.2°C | 68 mm | 75% | 4 m/s | 6.3 |
| 2002 | 22.6°C | 18.8°C | 15.0°C | 26.6°C | 10.9°C | 83 mm | 77% | 3.4 m/s | 6.3 |
| 2001 | 21.7°C | 18.0°C | 14.2°C | 25.1°C | 10.2°C | 29 mm | 73% | 4 m/s | 6.3 |
| 2000 | 22.5°C | 18.6°C | 14.6°C | 26.3°C | 10.7°C | 76 mm | 75% | 3.4 m/s | 5.8 |
| 1999 | 25.1°C | 21.0°C | 16.9°C | 28.2°C | 13.1°C | 104 mm | 76% | 3.5 m/s | 6.2 |
| 1998 | 22.1°C | 18.3°C | 14.5°C | 25.6°C | 8.4°C | 42 mm | 78% | 4.1 m/s | 6.3 |
| 1997 | 21.5°C | 17.4°C | 13.4°C | 24.6°C | 8.1°C | 41 mm | 75% | 3.9 m/s | 6.4 |
| 1996 | 23.5°C | 19.6°C | 15.8°C | 25.5°C | 11.0°C | 64 mm | 75% | 3.2 m/s | 6.2 |
| 1995 | 23.1°C | 19.0°C | 14.9°C | 27.0°C | 8.3°C | 57 mm | 74% | 3.4 m/s | 6.2 |
| 1994 | 23.3°C | 19.2°C | 15.1°C | 26.3°C | 9.2°C | 44 mm | 75% | 3.8 m/s | 6.5 |
| 1993 | 20.7°C | 16.9°C | 13.2°C | 23.0°C | 9.9°C | 57 mm | 77% | 4.5 m/s | 6.6 |
| 1992 | 22.1°C | 18.2°C | 14.4°C | 24.9°C | 8.9°C | 112 mm | 77% | 3.8 m/s | 6.2 |
| 1991 | 21.7°C | 17.9°C | 14.1°C | 25.1°C | 8.7°C | 95 mm | 77% | 4.7 m/s | 6 |
| 1990 | 22.5°C | 18.6°C | 14.7°C | 27.0°C | 11.5°C | 88 mm | 77% | 3.9 m/s | 5.7 |
| 1989 | 23.3°C | 19.7°C | 16.1°C | 27.2°C | 10.5°C | 173 mm | 79% | 4.4 m/s | 5.6 |
| 1988 | 22.5°C | 18.1°C | 13.8°C | 26.3°C | 11.1°C | 12 mm | 75% | 4.1 m/s | 6.8 |
| 1987 | 23.3°C | 19.1°C | 14.9°C | 26.4°C | 12.2°C | 93 mm | 75% | 3.7 m/s | 6.3 |
| 1986 | 23.7°C | 20.0°C | 16.2°C | 28.5°C | 9.7°C | 153 mm | 78% | 3.8 m/s | 5.8 |
| 1985 | 23.6°C | 19.8°C | 16.0°C | 28.3°C | 13.4°C | 92 mm | 76% | 3.8 m/s | 7 |
| 1984 | 21.7°C | 17.5°C | 13.2°C | 24.5°C | 8.6°C | 113 mm | 74% | 3.8 m/s | 6.5 |
| 1983 ❄️ | 20.7°C | 16.8°C | 13.0°C | 24.5°C | 10.1°C | 73 mm | 75% | 5 m/s | — |
| 1982 | 22.7°C | 18.8°C | 14.9°C | 26.0°C | 10.8°C | 54 mm | 74% | 4.3 m/s | — |
| 1981 | 24.2°C | 20.0°C | 15.8°C | 27.0°C | 12.0°C | 70 mm | 78% | 3.3 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around 22.8°C with lows near 14.9°C (mean 18.9°C), based on 45 years of NASA POWER data.
January averages 75 mm of rainfall in Hamilton, one of the drier months. The wettest on record was 262 mm in 2023.
The hottest January reached 29.5°C in 2018. The coldest dipped to 8.1°C in 1997.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 0.9°C. Daytime highs moved from 22.6°C to 23.4°C and overnight lows from 14.6°C to 15.5°C over the same span.
January is one of the warmer months of the year in Hamilton and one of the drier months, so plan for around 22.8°C daytime highs and 14.9°C at night.
Not quite — January is the 11th coolest month in Hamilton, averaging 18.9°C.
For January in Hamilton, pack light layers you can adjust through the day, with typical highs of 22.8°C and lows of 14.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in January averages 76% — quite humid.
Average wind speed in January is 3.8 m/s. The windiest January on record averaged 5 m/s (1983).
The wettest January on record was 2023 with 262 mm. On average, January sees 75 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 January, 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 January specifically, along with year-by-year records and how the month has changed over the decades.
