May is one of the cooler months of the year in Hamilton, with average highs near 16.1°C and lows around 10.1°C (mean 13.1°C). It is a relatively wet time of year, averaging 113 mm of rainfall and 84% relative humidity across the period.
May is one of the cooler months of the year in Hamilton. Across 45 years of records, the warmest May in Hamilton was 2016 — when the month averaged 15.2°C — while the coldest was 1992 at 10.6°C. Typical May days reach 16.1°C with nights near 10.1°C. The long-term trend is warming, about 0.2°C per decade.
May is a relatively wet time of year in Hamilton, averaging 113 mm of rainfall. The wettest May on record was 2023 with 220 mm, while the driest was 2007 at 24 mm.
Relative humidity in Hamilton during May averages 84%. The most humid May was 2023 at 88%, and the least humid was 2002 at 81%.
May receives about 2.4 kWh/m²/day of solar energy in Hamilton. The sunniest May was 1985 at 2.7 kWh/m²/day, and the cloudiest was 2001 at 2.
Average wind speed in Hamilton during May is 3.9 m/s. The windiest May was 1994 at 5.2 m/s, while the calmest was 1987 at 3.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 12.7°C | 12.8°C | 13.3°C | 13.4°C | 13.5°C | +0.8°C |
| Avg High | 15.8°C | 15.7°C | 16.2°C | 16.4°C | 16.6°C | +0.8°C |
| Avg Low | 9.6°C | 10.0°C | 10.4°C | 10.4°C | 10.4°C | +0.8°C |
| Avg Rain | 93 mm | 105 mm | 111 mm | 125 mm | 137 mm | +43 mm |
May temperatures in Hamilton have risen by about 1.2°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 2.2°C (2001) to a record high of 22°C (1989).
Rainfall in May is a relatively wet time of year, averaging 113 mm, with a wettest year of 220 mm.
A good time to visit Hamilton
May is a good time to visit Hamilton, with days averaging 16.1°C and nights around 10.1°C (mean 13.1°C, cooler than Hamilton's yearly average) and higher rainfall. February and January are marginally more temperate, but May still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 17.1°C | 13.7°C | 10.4°C | 20.2°C | 5.5°C | 143 mm | 84% | 3.6 m/s | 2.5 |
| 2024 | 15.2°C | 12.2°C | 9.2°C | 18.3°C | 2.9°C | 109 mm | 84% | 3.7 m/s | 2.6 |
| 2023 🌧️ | 17.1°C | 14.6°C | 12.1°C | 20.9°C | 6.6°C | 220 mm | 88% | 4.5 m/s | 2.2 |
| 2022 | 17.5°C | 14.3°C | 11.2°C | 20.0°C | 5.4°C | 138 mm | 84% | 3.7 m/s | 2.5 |
| 2021 | 16.5°C | 13.3°C | 10.2°C | 19.3°C | 3.8°C | 106 mm | 83% | 3.8 m/s | 2.5 |
| 2020 | 16.3°C | 12.9°C | 9.4°C | 19.1°C | 4.6°C | 106 mm | 83% | 3.4 m/s | 2.3 |
| 2019 | 17.2°C | 14.1°C | 11.0°C | 19.5°C | 6.4°C | 71 mm | 84% | 3.4 m/s | 2.4 |
| 2018 | 16.5°C | 13.5°C | 10.5°C | 21.5°C | 4.0°C | 136 mm | 85% | 4 m/s | 2.5 |
| 2017 | 15.7°C | 12.6°C | 9.6°C | 19.2°C | 3.8°C | 149 mm | 84% | 3.6 m/s | 2.5 |
| 2016 🔥 | 17.8°C | 15.2°C | 12.6°C | 21.0°C | 7.9°C | 136 mm | 85% | 4.3 m/s | 2.2 |
| 2015 | 15.9°C | 12.9°C | 9.9°C | 20.2°C | 3.3°C | 109 mm | 82% | 3.9 m/s | 2.3 |
| 2014 | 16.2°C | 13.0°C | 9.7°C | 19.5°C | 2.4°C | 59 mm | 83% | 3.2 m/s | 2.5 |
| 2013 | 16.6°C | 13.4°C | 10.3°C | 19.9°C | 4.0°C | 171 mm | 85% | 3.6 m/s | 2.3 |
| 2012 | 15.3°C | 11.9°C | 8.5°C | 18.5°C | 3.4°C | 98 mm | 83% | 3.7 m/s | 2.5 |
| 2011 | 16.8°C | 14.4°C | 11.9°C | 20.1°C | 6.7°C | 154 mm | 87% | 4.4 m/s | 2.2 |
| 2010 | 16.3°C | 13.0°C | 9.7°C | 19.7°C | 5.1°C | 167 mm | 84% | 3.7 m/s | 2.2 |
| 2009 | 14.0°C | 11.0°C | 8.0°C | 17.8°C | 3.2°C | 113 mm | 84% | 4.1 m/s | 2.3 |
| 2008 | 15.4°C | 12.0°C | 8.6°C | 17.4°C | 4.7°C | 95 mm | 82% | 3.2 m/s | 2.6 |
| 2007 | 17.4°C | 14.4°C | 11.4°C | 20.0°C | 5.8°C | 24 mm | 85% | 3.3 m/s | 2.4 |
| 2006 | 16.0°C | 13.0°C | 10.1°C | 19.2°C | 5.5°C | 121 mm | 86% | 3.9 m/s | 2.4 |
| 2005 | 16.8°C | 14.0°C | 11.2°C | 19.5°C | 5.6°C | 202 mm | 88% | 3.8 m/s | 2.1 |
| 2004 | 16.4°C | 13.4°C | 10.5°C | 19.3°C | 6.4°C | 154 mm | 87% | 4.1 m/s | 2.2 |
| 2003 | 16.9°C | 14.0°C | 11.0°C | 19.9°C | 5.0°C | 112 mm | 83% | 3.5 m/s | 2.4 |
| 2002 | 16.1°C | 13.7°C | 11.3°C | 18.4°C | 7.1°C | 62 mm | 81% | 5.1 m/s | 2.1 |
| 2001 | 16.2°C | 13.7°C | 11.2°C | 20.9°C | 2.2°C | 142 mm | 86% | 4.8 m/s | 2 |
| 2000 | 16.9°C | 13.8°C | 10.7°C | 20.3°C | 6.7°C | 89 mm | 85% | 3.9 m/s | 2.2 |
| 1999 | 17.1°C | 14.0°C | 10.8°C | 19.7°C | 6.5°C | 69 mm | 84% | 3.8 m/s | 2.3 |
| 1998 | 16.5°C | 13.5°C | 10.5°C | 18.3°C | 7.0°C | 81 mm | 84% | 4.3 m/s | 2.2 |
| 1997 | 16.7°C | 13.7°C | 10.7°C | 19.3°C | 8.5°C | 102 mm | 85% | 3.2 m/s | 2.2 |
| 1996 | 15.3°C | 12.1°C | 9.0°C | 18.1°C | 4.2°C | 104 mm | 84% | 4.3 m/s | 2.4 |
| 1995 | 16.2°C | 13.2°C | 10.2°C | 20.7°C | 5.1°C | 147 mm | 85% | 3.9 m/s | 2.4 |
| 1994 | 15.8°C | 13.2°C | 10.6°C | 18.8°C | 5.8°C | 138 mm | 84% | 5.2 m/s | 2.4 |
| 1993 | 15.3°C | 12.6°C | 9.9°C | 17.8°C | 5.6°C | 74 mm | 85% | 4.1 m/s | 2.3 |
| 1992 ❄️ | 13.4°C | 10.6°C | 7.8°C | 19.0°C | 2.8°C | 124 mm | 85% | 4.2 m/s | 2.3 |
| 1991 | 14.8°C | 12.1°C | 9.5°C | 18.1°C | 7.0°C | 68 mm | 85% | 3.7 m/s | 2.4 |
| 1990 | 15.7°C | 13.3°C | 11.0°C | 18.5°C | 6.1°C | 140 mm | 83% | 4.6 m/s | 2.5 |
| 1989 | 16.1°C | 13.2°C | 10.2°C | 22.0°C | 4.5°C | 114 mm | 84% | 3.6 m/s | 2.4 |
| 1988 | 15.9°C | 13.1°C | 10.3°C | 20.1°C | 5.9°C | 106 mm | 86% | 4.1 m/s | 2.1 |
| 1987 | 15.8°C | 12.7°C | 9.7°C | 19.0°C | 6.3°C | 82 mm | 85% | 3.1 m/s | 2.3 |
| 1986 | 16.3°C | 13.1°C | 9.9°C | 18.7°C | 3.9°C | 138 mm | 83% | 3.8 m/s | 2.6 |
| 1985 | 15.4°C | 12.0°C | 8.7°C | 18.2°C | 5.4°C | 72 mm | 83% | 3.2 m/s | 2.7 |
| 1984 | 15.3°C | 12.3°C | 9.3°C | 19.5°C | 2.6°C | 91 mm | 83% | 4 m/s | 2.4 |
| 1983 | 14.9°C | 12.2°C | 9.5°C | 19.2°C | 4.2°C | 85 mm | 84% | 4.9 m/s | — |
| 1982 | 15.9°C | 12.7°C | 9.4°C | 18.8°C | 5.0°C | 97 mm | 82% | 4.3 m/s | — |
| 1981 | 16.2°C | 12.8°C | 9.4°C | 20.1°C | 5.0°C | 55 mm | 83% | 3.5 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 16.1°C with lows near 10.1°C (mean 13.1°C), based on 45 years of NASA POWER data.
May averages 113 mm of rainfall in Hamilton, a relatively wet time of year. The wettest on record was 220 mm in 2023.
The hottest May reached 22°C in 1989. The coldest dipped to 2.2°C in 2001.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.2°C. Daytime highs moved from 15.5°C to 16.7°C and overnight lows from 9.3°C to 10.6°C over the same span.
May is one of the cooler months of the year in Hamilton and a relatively wet time of year, so plan for around 16.1°C daytime highs and 10.1°C at night.
Not quite — May is the 5th coolest month in Hamilton, averaging 13.1°C.
For May in Hamilton, pack light layers you can adjust through the day, with typical highs of 16.1°C and lows of 10.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 84% — quite humid.
Average wind speed in May is 3.9 m/s. The windiest May on record averaged 5.2 m/s (1994).
The wettest May on record was 2023 with 220 mm. On average, May sees 113 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 May, 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 May specifically, along with year-by-year records and how the month has changed over the decades.
