January is one of the warmer months of the year in Hamilton, with average highs near 28.4°C and lows around 12.1°C (mean 20.3°C). It is one of the drier months, averaging 33 mm of rainfall and 56% 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 2022 — when the month averaged 23.4°C — while the coldest was 1987 at 17.2°C. Typical January days reach 28.4°C with nights near 12.1°C. The long-term trend is warming, about 0.4°C per decade.
January is one of the drier months in Hamilton, averaging 33 mm of rainfall. The wettest January on record was 2011 with 134 mm, while the driest was 2019 at 2 mm.
Relative humidity in Hamilton during January averages 56%. The most humid January was 2011 at 70%, and the least humid was 2019 at 48%.
January receives about 7.3 kWh/m²/day of solar energy in Hamilton. The sunniest January was 2009 at 8.3 kWh/m²/day, and the cloudiest were 2002 and 2015 at 6.5.
Average wind speed in Hamilton during January is 3.5 m/s. The windiest January was 2012 at 4 m/s, while the calmest was 2011 at 2.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 19.6°C | 19.9°C | 20.1°C | 21.0°C | 21.0°C | +1.4°C |
| Avg High | 27.9°C | 28.0°C | 28.2°C | 29.3°C | 28.9°C | +1°C |
| Avg Low | 11.4°C | 11.8°C | 12.0°C | 12.7°C | 13.1°C | +1.7°C |
| Avg Rain | 26 mm | 34 mm | 33 mm | 36 mm | 40 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 4.3°C (1987) to a record high of 44.4°C (1982).
Rainfall in January is one of the drier months, averaging 33 mm, with a wettest year of 134 mm.
One of the best times to visit Hamilton
January is one of the best times to visit Hamilton. Expect days averaging 28.4°C and nights around 12.1°C (mean 20.3°C) — warmer than Hamilton's yearly average — with moderate rainfall (33 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 | 29.9°C | 21.8°C | 13.6°C | 40.9°C | 8.3°C | 12 mm | 51% | 3.4 m/s | 7.3 |
| 2024 | 27.7°C | 20.4°C | 13.1°C | 34.5°C | 10.5°C | 61 mm | 65% | 3.3 m/s | 7 |
| 2023 | 28.8°C | 20.6°C | 12.3°C | 38.3°C | 9.0°C | 14 mm | 57% | 3.5 m/s | 7.6 |
| 2022 🔥 | 31.1°C | 23.4°C | 15.6°C | 38.0°C | 11.4°C | 48 mm | 55% | 3.5 m/s | 7.1 |
| 2021 | 27.1°C | 19.4°C | 11.8°C | 38.9°C | 7.2°C | 67 mm | 62% | 3.6 m/s | 7.1 |
| 2020 | 28.8°C | 20.4°C | 11.9°C | 40.8°C | 8.1°C | 38 mm | 54% | 3.4 m/s | 7.1 |
| 2019 | 32.6°C | 23.1°C | 13.6°C | 42.5°C | 8.0°C | 2 mm | 48% | 3.3 m/s | 8 |
| 2018 | 31.2°C | 22.3°C | 13.4°C | 43.5°C | 8.9°C | 11 mm | 50% | 3.4 m/s | 7.6 |
| 2017 | 29.2°C | 20.9°C | 12.5°C | 38.1°C | 8.4°C | 34 mm | 55% | 3.3 m/s | 7.6 |
| 2016 | 29.0°C | 21.1°C | 13.2°C | 39.5°C | 9.1°C | 42 mm | 55% | 3.4 m/s | 7.1 |
| 2015 | 27.2°C | 19.7°C | 12.1°C | 41.3°C | 7.3°C | 65 mm | 59% | 3.7 m/s | 6.5 |
| 2014 | 30.5°C | 21.9°C | 13.3°C | 43.7°C | 8.3°C | 23 mm | 51% | 3.8 m/s | 7.5 |
| 2013 | 29.1°C | 20.5°C | 11.9°C | 42.7°C | 8.7°C | 11 mm | 50% | 3.5 m/s | 7.9 |
| 2012 | 29.2°C | 21.4°C | 13.6°C | 41.4°C | 8.7°C | 20 mm | 53% | 4 m/s | 7.2 |
| 2011 🌧️ | 26.0°C | 19.0°C | 11.9°C | 36.9°C | 6.4°C | 134 mm | 70% | 2.9 m/s | 7.1 |
| 2010 | 29.1°C | 20.2°C | 11.3°C | 42.4°C | 8.1°C | 13 mm | 52% | 3.3 m/s | 7.5 |
| 2009 | 29.5°C | 20.4°C | 11.3°C | 43.7°C | 5.2°C | 5 mm | 50% | 3.3 m/s | 8.3 |
| 2008 | 28.7°C | 20.5°C | 12.4°C | 40.8°C | 8.5°C | 30 mm | 58% | 3.6 m/s | 7.7 |
| 2007 | 27.8°C | 20.3°C | 12.9°C | 40.0°C | 7.8°C | 109 mm | 62% | 3.4 m/s | 7.2 |
| 2006 | 30.0°C | 21.4°C | 12.9°C | 41.7°C | 8.0°C | 39 mm | 55% | 3.6 m/s | 7.4 |
| 2005 | 28.1°C | 20.0°C | 11.9°C | 40.6°C | 7.7°C | 35 mm | 57% | 3.5 m/s | 7.3 |
| 2004 | 24.4°C | 17.3°C | 10.1°C | 34.7°C | 6.4°C | 31 mm | 61% | 3.4 m/s | 7 |
| 2003 | 29.2°C | 20.5°C | 11.9°C | 44.2°C | 6.9°C | 29 mm | 52% | 3.7 m/s | 7.4 |
| 2002 | 25.9°C | 18.2°C | 10.4°C | 37.2°C | 6.4°C | 20 mm | 61% | 3.5 m/s | 6.5 |
| 2001 | 31.5°C | 22.8°C | 14.0°C | 42.2°C | 8.7°C | 24 mm | 51% | 3.6 m/s | 7 |
| 2000 | 27.3°C | 19.9°C | 12.5°C | 40.6°C | 7.2°C | 10 mm | 55% | 3.7 m/s | 7 |
| 1999 | 31.1°C | 22.2°C | 13.2°C | 41.0°C | 9.3°C | 18 mm | 55% | 3.6 m/s | 7.6 |
| 1998 | 28.7°C | 20.5°C | 12.4°C | 42.4°C | 8.8°C | 21 mm | 56% | 3.6 m/s | 6.9 |
| 1997 | 29.8°C | 21.1°C | 12.4°C | 41.9°C | 8.6°C | 35 mm | 51% | 3.8 m/s | 7.4 |
| 1996 | 27.2°C | 19.2°C | 11.1°C | 40.2°C | 7.9°C | 30 mm | 58% | 3.8 m/s | 7.1 |
| 1995 | 29.1°C | 20.9°C | 12.7°C | 38.6°C | 6.4°C | 31 mm | 56% | 3.5 m/s | 7.1 |
| 1994 | 25.3°C | 17.4°C | 9.6°C | 39.3°C | 5.6°C | 40 mm | 58% | 3.8 m/s | 7.1 |
| 1993 | 27.9°C | 20.0°C | 12.1°C | 39.5°C | 7.5°C | 58 mm | 62% | 3 m/s | 7 |
| 1992 | 24.7°C | 17.5°C | 10.4°C | 35.8°C | 6.9°C | 11 mm | 60% | 3.8 m/s | 7.2 |
| 1991 | 27.7°C | 19.9°C | 12.1°C | 41.6°C | 7.9°C | 83 mm | 61% | 3.6 m/s | 7 |
| 1990 | 28.4°C | 20.1°C | 11.8°C | 38.7°C | 6.5°C | 10 mm | 52% | 3.8 m/s | 7.6 |
| 1989 | 27.5°C | 19.8°C | 12.0°C | 39.1°C | 6.9°C | 24 mm | 53% | 3.7 m/s | 7.3 |
| 1988 | 29.6°C | 21.1°C | 12.6°C | 40.2°C | 8.7°C | 29 mm | 53% | 3.2 m/s | 7.3 |
| 1987 ❄️ | 25.0°C | 17.2°C | 9.4°C | 36.9°C | 4.3°C | 33 mm | 59% | 3.5 m/s | 7.1 |
| 1986 | 25.4°C | 17.5°C | 9.7°C | 38.9°C | 7.4°C | 17 mm | 59% | 3.6 m/s | 7.5 |
| 1985 | 27.8°C | 19.4°C | 11.1°C | 41.6°C | 6.7°C | 14 mm | 53% | 3.6 m/s | 7.3 |
| 1984 | 26.1°C | 18.5°C | 10.9°C | 34.0°C | 7.1°C | 26 mm | 58% | 3.6 m/s | 7 |
| 1983 | 27.4°C | 18.8°C | 10.1°C | 41.0°C | 6.5°C | 20 mm | 50% | 3.6 m/s | — |
| 1982 | 30.4°C | 21.8°C | 13.2°C | 44.4°C | 8.7°C | 31 mm | 50% | 3.6 m/s | — |
| 1981 | 31.8°C | 22.7°C | 13.6°C | 41.9°C | 9.0°C | 41 mm | 50% | 3.8 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around 28.4°C with lows near 12.1°C (mean 20.3°C), based on 45 years of NASA POWER data.
January averages 33 mm of rainfall in Hamilton, one of the drier months. The wettest on record was 134 mm in 2011.
The hottest January reached 44.4°C in 1982. The coldest dipped to 4.3°C in 1987.
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 28.7°C to 28.9°C and overnight lows from 11.8°C to 13.3°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 28.4°C daytime highs and 12.1°C at night.
Not quite — January is the 12th coolest month in Hamilton, averaging 20.3°C.
For January in Hamilton, pack light layers you can adjust through the day, with typical highs of 28.4°C and lows of 12.1°C.
Relative humidity in January averages 56% — moderately humid.
Average wind speed in January is 3.5 m/s. The windiest January on record averaged 4 m/s (2012).
The wettest January on record was 2011 with 134 mm. On average, January sees 33 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.
