May is one of the cooler months of the year in Greymouth, with average highs near 12.3°C and lows around 7.8°C (mean 10.1°C). It is a relatively wet time of year, averaging 178 mm of rainfall and 88% relative humidity across the period.
May is one of the cooler months of the year in Greymouth. Across 45 years of records, the warmest May in Greymouth was 2023 — when the month averaged 12°C — while the coldest was 1992 at 7.6°C. Typical May days reach 12.3°C with nights near 7.8°C. The long-term trend is warming, about 0.3°C per decade.
May is a relatively wet time of year in Greymouth, averaging 178 mm of rainfall. The wettest May on record was 2016 with 369 mm, while the driest was 2008 at 64 mm.
Relative humidity in Greymouth during May averages 88%. The most humid May was 2023 at 91%, and the least humid was 2008 at 83%.
May receives about 1.7 kWh/m²/day of solar energy in Greymouth. The sunniest May was 1985 at 2.1 kWh/m²/day, and the cloudiest were 2011 and 2016 at 1.4.
Average wind speed in Greymouth during May is 1.4 m/s. The windiest Mays were 1982, 1983 and 2002 at 1.6 m/s, while the calmest were 2006 and 2020 at 1.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 9.5°C | 9.8°C | 10.0°C | 10.4°C | 10.9°C | +1.4°C |
| Avg High | 11.9°C | 12.1°C | 12.3°C | 12.6°C | 13.0°C | +1.1°C |
| Avg Low | 7.1°C | 7.6°C | 7.7°C | 8.2°C | 8.7°C | +1.6°C |
| Avg Rain | 160 mm | 167 mm | 162 mm | 204 mm | 209 mm | +49 mm |
May temperatures in Greymouth have risen by about 1.5°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 0°C (1992) to a record high of 19.3°C (2023).
Rainfall in May is a relatively wet time of year, averaging 178 mm, with a wettest year of 369 mm.
A good time to visit Greymouth
May is a good time to visit Greymouth, with days averaging 12.3°C and nights around 7.8°C (mean 10.1°C, cooler than Greymouth'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 | 13.5°C | 11.4°C | 9.3°C | 16.0°C | 5.8°C | 192 mm | 89% | 1.4 m/s | 1.8 |
| 2024 | 11.4°C | 9.1°C | 6.8°C | 15.3°C | 3.3°C | 76 mm | 86% | 1.2 m/s | 1.9 |
| 2023 🔥 | 13.8°C | 12.0°C | 10.2°C | 19.3°C | 5.9°C | 363 mm | 91% | 1.3 m/s | 1.5 |
| 2022 | 13.9°C | 11.8°C | 9.8°C | 17.3°C | 4.6°C | 278 mm | 90% | 1.3 m/s | 1.7 |
| 2021 | 12.6°C | 10.4°C | 8.2°C | 16.7°C | 2.7°C | 199 mm | 88% | 1.4 m/s | 1.8 |
| 2020 | 12.6°C | 10.4°C | 8.1°C | 14.8°C | 3.1°C | 145 mm | 88% | 1.1 m/s | 1.8 |
| 2019 | 13.8°C | 11.8°C | 9.9°C | 16.9°C | 5.2°C | 274 mm | 90% | 1.4 m/s | 1.6 |
| 2018 | 12.0°C | 9.8°C | 7.7°C | 15.6°C | 2.0°C | 208 mm | 88% | 1.4 m/s | 1.7 |
| 2017 | 12.4°C | 9.9°C | 7.4°C | 14.9°C | 2.9°C | 173 mm | 87% | 1.3 m/s | 1.8 |
| 2016 🌧️ | 13.0°C | 11.1°C | 9.3°C | 17.0°C | 3.5°C | 369 mm | 90% | 1.4 m/s | 1.4 |
| 2015 | 12.2°C | 10.1°C | 8.0°C | 15.9°C | 2.6°C | 224 mm | 88% | 1.4 m/s | 1.7 |
| 2014 | 12.7°C | 10.3°C | 7.9°C | 16.0°C | 2.1°C | 191 mm | 89% | 1.3 m/s | 1.6 |
| 2013 | 12.4°C | 10.0°C | 7.6°C | 15.6°C | 0.8°C | 114 mm | 86% | 1.3 m/s | 1.9 |
| 2012 | 12.0°C | 9.6°C | 7.1°C | 14.9°C | 2.9°C | 91 mm | 86% | 1.2 m/s | 1.9 |
| 2011 | 13.2°C | 11.3°C | 9.4°C | 17.1°C | 3.7°C | 264 mm | 90% | 1.5 m/s | 1.4 |
| 2010 | 12.1°C | 9.7°C | 7.4°C | 16.1°C | 2.5°C | 132 mm | 87% | 1.3 m/s | 1.8 |
| 2009 | 10.4°C | 8.0°C | 5.5°C | 14.2°C | 1.0°C | 140 mm | 83% | 1.4 m/s | 1.9 |
| 2008 | 11.8°C | 9.1°C | 6.3°C | 14.2°C | 2.6°C | 64 mm | 83% | 1.2 m/s | 2 |
| 2007 | 13.4°C | 11.3°C | 9.2°C | 15.7°C | 4.7°C | 149 mm | 90% | 1.4 m/s | 1.6 |
| 2006 | 12.4°C | 10.0°C | 7.5°C | 15.3°C | 2.5°C | 174 mm | 88% | 1.1 m/s | 1.9 |
| 2005 | 12.3°C | 10.1°C | 7.9°C | 15.6°C | 3.8°C | 140 mm | 89% | 1.3 m/s | 1.8 |
| 2004 | 12.5°C | 10.2°C | 7.8°C | 14.9°C | 4.5°C | 207 mm | 89% | 1.5 m/s | 1.6 |
| 2003 | 12.6°C | 10.4°C | 8.1°C | 15.4°C | 3.3°C | 243 mm | 89% | 1.4 m/s | 1.6 |
| 2002 | 12.1°C | 10.0°C | 7.9°C | 16.0°C | 3.2°C | 156 mm | 89% | 1.6 m/s | 1.6 |
| 2001 | 12.4°C | 10.1°C | 7.8°C | 17.7°C | 0.6°C | 139 mm | 86% | 1.5 m/s | 1.8 |
| 2000 | 12.6°C | 10.7°C | 8.8°C | 15.7°C | 5.1°C | 206 mm | 90% | 1.4 m/s | 1.6 |
| 1999 | 13.8°C | 11.4°C | 8.9°C | 16.0°C | 3.1°C | 99 mm | 87% | 1.3 m/s | 1.8 |
| 1998 | 12.5°C | 10.1°C | 7.7°C | 15.1°C | 2.3°C | 144 mm | 88% | 1.3 m/s | 1.7 |
| 1997 | 12.7°C | 10.5°C | 8.4°C | 16.8°C | 6.3°C | 119 mm | 89% | 1.3 m/s | 1.7 |
| 1996 | 11.8°C | 9.4°C | 7.0°C | 16.0°C | 2.5°C | 145 mm | 88% | 1.4 m/s | 1.8 |
| 1995 | 12.7°C | 10.3°C | 7.9°C | 15.8°C | 2.4°C | 180 mm | 87% | 1.4 m/s | 1.9 |
| 1994 | 11.7°C | 9.7°C | 7.7°C | 14.8°C | 3.8°C | 287 mm | 89% | 1.5 m/s | 1.6 |
| 1993 | 11.9°C | 9.8°C | 7.7°C | 14.5°C | 3.4°C | 205 mm | 90% | 1.4 m/s | 1.7 |
| 1992 ❄️ | 10.0°C | 7.6°C | 5.1°C | 14.1°C | 0.0°C | 130 mm | 83% | 1.3 m/s | 2 |
| 1991 | 11.6°C | 9.6°C | 7.7°C | 14.1°C | 3.6°C | 112 mm | 88% | 1.3 m/s | 1.9 |
| 1990 | 11.8°C | 9.9°C | 7.9°C | 14.7°C | 4.8°C | 249 mm | 90% | 1.5 m/s | 1.6 |
| 1989 | 12.5°C | 10.0°C | 7.6°C | 16.9°C | 1.2°C | 150 mm | 86% | 1.2 m/s | 1.8 |
| 1988 | 11.1°C | 8.6°C | 6.1°C | 14.6°C | 1.2°C | 224 mm | 86% | 1.4 m/s | 1.7 |
| 1987 | 12.4°C | 10.4°C | 8.5°C | 14.8°C | 4.7°C | 221 mm | 89% | 1.3 m/s | 1.7 |
| 1986 | 12.2°C | 9.8°C | 7.3°C | 16.4°C | 2.3°C | 140 mm | 88% | 1.4 m/s | 1.8 |
| 1985 | 12.4°C | 10.0°C | 7.5°C | 15.9°C | 4.3°C | 85 mm | 85% | 1.2 m/s | 2.1 |
| 1984 | 11.2°C | 8.7°C | 6.2°C | 15.2°C | 1.9°C | 134 mm | 85% | 1.3 m/s | 1.7 |
| 1983 | 10.8°C | 8.6°C | 6.4°C | 14.8°C | 1.1°C | 139 mm | 87% | 1.6 m/s | — |
| 1982 | 12.2°C | 9.9°C | 7.6°C | 14.6°C | 5.1°C | 245 mm | 87% | 1.6 m/s | — |
| 1981 | 12.4°C | 9.8°C | 7.1°C | 16.6°C | 3.6°C | 102 mm | 84% | 1.2 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 12.3°C with lows near 7.8°C (mean 10.1°C), based on 45 years of NASA POWER data.
May averages 178 mm of rainfall in Greymouth, a relatively wet time of year. The wettest on record was 369 mm in 2016.
The hottest May reached 19.3°C in 2023. The coldest dipped to 0°C in 1992.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.5°C. Daytime highs moved from 11.8°C to 13°C and overnight lows from 7°C to 8.9°C over the same span.
May is one of the cooler months of the year in Greymouth and a relatively wet time of year, so plan for around 12.3°C daytime highs and 7.8°C at night.
Not quite — May is the 5th coolest month in Greymouth, averaging 10.1°C.
For May in Greymouth, pack warm layers and a jacket for chilly mornings, with typical highs of 12.3°C and lows of 7.8°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 88% — quite humid.
Average wind speed in May is 1.4 m/s. The windiest May on record averaged 1.6 m/s (1982).
The wettest May on record was 2016 with 369 mm. On average, May sees 178 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 Greymouth 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.
