May is one of the cooler months of the year in Rolleston, with average highs near 14.1°C and lows around 5.2°C (mean 9.7°C). It is about average for rainfall, averaging 78 mm of rainfall and 84% relative humidity across the period.
May is one of the cooler months of the year in Rolleston. Across 45 years of records, the warmest May in Rolleston was 1999 — when the month averaged 11.6°C — while the coldest was 1992 at 7°C. Typical May days reach 14.1°C with nights near 5.2°C. The long-term trend is warming, about 0.3°C per decade.
May is about average for rainfall in Rolleston, averaging 78 mm of rainfall. The wettest May on record was 2016 with 162 mm, while the driest was 2012 at 25 mm.
Relative humidity in Rolleston during May averages 84%. The most humid May was 2023 at 90%, and the least humid was 1988 at 77%.
May receives about 1.9 kWh/m²/day of solar energy in Rolleston. The sunniest Mays were 1991 and 2025 at 2.1 kWh/m²/day, and the cloudiest was 2010 at 1.6.
Average wind speed in Rolleston during May is 2.5 m/s. The windiest May was 1983 at 3.4 m/s, while the calmest was 1997 at 1.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 9.1°C | 9.5°C | 9.6°C | 9.9°C | 10.2°C | +1.1°C |
| Avg High | 13.6°C | 14.0°C | 13.9°C | 14.2°C | 14.7°C | +1.1°C |
| Avg Low | 4.7°C | 5.1°C | 5.3°C | 5.6°C | 5.7°C | +1°C |
| Avg Rain | 74 mm | 68 mm | 70 mm | 89 mm | 93 mm | +19 mm |
May temperatures in Rolleston have risen by about 1.2°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -1.8°C (1988) to a record high of 24.4°C (2013).
Rainfall in May is about average for rainfall, averaging 78 mm, with a wettest year of 162 mm.
A good time to visit Rolleston
May is a good time to visit Rolleston, with days averaging 14.1°C and nights around 5.2°C (mean 9.7°C, cooler than Rolleston's yearly average) and moderate 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 | 14.8°C | 10.2°C | 5.6°C | 18.5°C | 3.0°C | 92 mm | 87% | 2.4 m/s | 2.1 |
| 2024 | 12.8°C | 8.1°C | 3.3°C | 17.9°C | 0.1°C | 45 mm | 83% | 2.1 m/s | 2 |
| 2023 | 14.9°C | 11.2°C | 7.6°C | 21.3°C | 2.1°C | 131 mm | 90% | 2.3 m/s | 1.7 |
| 2022 | 16.1°C | 11.4°C | 6.7°C | 21.5°C | 2.1°C | 93 mm | 85% | 2.1 m/s | 2 |
| 2021 | 15.0°C | 10.2°C | 5.4°C | 23.0°C | -0.2°C | 146 mm | 84% | 2.5 m/s | 2 |
| 2020 | 14.8°C | 10.1°C | 5.5°C | 21.1°C | 1.1°C | 52 mm | 86% | 2.1 m/s | 1.9 |
| 2019 | 16.5°C | 11.5°C | 6.6°C | 21.1°C | 2.8°C | 96 mm | 85% | 2.4 m/s | 1.9 |
| 2018 | 13.1°C | 9.4°C | 5.6°C | 18.1°C | 0.7°C | 82 mm | 87% | 2.4 m/s | 1.9 |
| 2017 | 13.1°C | 8.6°C | 4.0°C | 17.7°C | -0.2°C | 69 mm | 89% | 2.1 m/s | 2 |
| 2016 🌧️ | 15.1°C | 11.2°C | 7.2°C | 21.8°C | 4.1°C | 162 mm | 83% | 3 m/s | 1.8 |
| 2015 | 14.1°C | 9.4°C | 4.8°C | 19.6°C | -1.3°C | 61 mm | 83% | 2.7 m/s | 2 |
| 2014 | 14.5°C | 9.8°C | 5.2°C | 19.5°C | -1.3°C | 61 mm | 85% | 2.5 m/s | 2 |
| 2013 | 14.2°C | 10.0°C | 5.8°C | 24.4°C | 1.7°C | 71 mm | 84% | 2.5 m/s | 1.8 |
| 2012 | 13.5°C | 8.9°C | 4.4°C | 18.7°C | 0.6°C | 25 mm | 84% | 2.3 m/s | 1.9 |
| 2011 | 14.6°C | 10.5°C | 6.4°C | 19.2°C | 0.6°C | 98 mm | 87% | 2.2 m/s | 1.7 |
| 2010 | 13.8°C | 9.9°C | 5.9°C | 20.1°C | 0.4°C | 161 mm | 86% | 2.4 m/s | 1.6 |
| 2009 | 10.9°C | 7.2°C | 3.5°C | 17.3°C | 0.4°C | 132 mm | 87% | 3.2 m/s | 1.8 |
| 2008 | 12.5°C | 8.0°C | 3.6°C | 17.5°C | -0.1°C | 46 mm | 86% | 2.1 m/s | 2 |
| 2007 | 16.4°C | 11.4°C | 6.3°C | 20.2°C | 2.9°C | 38 mm | 81% | 2.5 m/s | 2 |
| 2006 | 13.1°C | 9.4°C | 5.7°C | 19.0°C | 1.3°C | 103 mm | 90% | 2.3 m/s | 1.7 |
| 2005 | 14.4°C | 9.8°C | 5.2°C | 19.9°C | 0.3°C | 78 mm | 85% | 2.2 m/s | 2 |
| 2004 | 13.9°C | 10.0°C | 6.1°C | 21.0°C | 0.9°C | 80 mm | 86% | 2.7 m/s | 1.8 |
| 2003 | 14.3°C | 9.9°C | 5.5°C | 21.4°C | 1.1°C | 69 mm | 84% | 2.3 m/s | 1.8 |
| 2002 | 14.8°C | 10.0°C | 5.3°C | 22.4°C | -0.9°C | 40 mm | 81% | 2.8 m/s | 1.9 |
| 2001 | 14.2°C | 10.2°C | 6.3°C | 21.3°C | -0.9°C | 53 mm | 82% | 2.5 m/s | 1.7 |
| 2000 | 14.5°C | 9.8°C | 5.0°C | 21.1°C | -0.2°C | 62 mm | 85% | 2.3 m/s | 1.7 |
| 1999 🔥 | 16.5°C | 11.6°C | 6.7°C | 21.1°C | 1.9°C | 28 mm | 79% | 2.5 m/s | 1.8 |
| 1998 | 15.0°C | 10.5°C | 6.0°C | 21.1°C | -0.3°C | 63 mm | 80% | 2.7 m/s | 1.8 |
| 1997 | 14.7°C | 10.3°C | 5.8°C | 21.0°C | 2.2°C | 73 mm | 84% | 1.9 m/s | 1.9 |
| 1996 | 14.1°C | 9.2°C | 4.4°C | 20.0°C | 0.5°C | 41 mm | 83% | 2.4 m/s | 1.9 |
| 1995 | 13.6°C | 9.4°C | 5.2°C | 19.2°C | 0.9°C | 71 mm | 87% | 2.3 m/s | 1.9 |
| 1994 | 13.6°C | 9.5°C | 5.4°C | 20.6°C | 1.0°C | 90 mm | 82% | 2.8 m/s | 1.9 |
| 1993 | 13.6°C | 9.1°C | 4.6°C | 18.2°C | 0.7°C | 87 mm | 86% | 2.4 m/s | 1.8 |
| 1992 ❄️ | 11.2°C | 7.0°C | 2.9°C | 17.4°C | -1.4°C | 96 mm | 83% | 2.8 m/s | 2 |
| 1991 | 13.6°C | 9.0°C | 4.4°C | 16.7°C | 2.1°C | 34 mm | 85% | 2.1 m/s | 2.1 |
| 1990 | 14.5°C | 9.8°C | 5.2°C | 21.2°C | -0.5°C | 102 mm | 82% | 3 m/s | 2 |
| 1989 | 13.8°C | 9.8°C | 5.8°C | 20.2°C | -0.5°C | 100 mm | 86% | 2.7 m/s | 1.7 |
| 1988 | 13.6°C | 8.3°C | 3.1°C | 19.6°C | -1.8°C | 83 mm | 77% | 2.3 m/s | 2 |
| 1987 | 14.3°C | 10.0°C | 5.7°C | 19.4°C | 0.9°C | 95 mm | 86% | 2.4 m/s | 1.8 |
| 1986 | 14.1°C | 9.3°C | 4.5°C | 19.7°C | -0.6°C | 50 mm | 84% | 2.4 m/s | 2 |
| 1985 | 13.6°C | 9.5°C | 5.5°C | 20.5°C | 1.5°C | 57 mm | 85% | 2.2 m/s | 1.9 |
| 1984 | 12.2°C | 8.0°C | 3.8°C | 18.3°C | 0.2°C | 66 mm | 83% | 2.4 m/s | 2 |
| 1983 | 12.9°C | 8.6°C | 4.4°C | 19.7°C | 0.4°C | 85 mm | 82% | 3.4 m/s | — |
| 1982 | 14.6°C | 9.9°C | 5.2°C | 19.1°C | 1.5°C | 87 mm | 79% | 2.9 m/s | — |
| 1981 | 13.2°C | 8.8°C | 4.5°C | 21.0°C | 0.4°C | 43 mm | 85% | 2.1 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 14.1°C with lows near 5.2°C (mean 9.7°C), based on 45 years of NASA POWER data.
May averages 78 mm of rainfall in Rolleston, about average for rainfall. The wettest on record was 162 mm in 2016.
The hottest May reached 24.4°C in 2013. The coldest dipped to -1.8°C in 1988.
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 13.3°C to 14.7°C and overnight lows from 4.7°C to 5.7°C over the same span.
May is one of the cooler months of the year in Rolleston and about average for rainfall, so plan for around 14.1°C daytime highs and 5.2°C at night.
Not quite — May is the 5th coolest month in Rolleston, averaging 9.7°C.
For May in Rolleston, pack warm layers and a jacket for chilly mornings, with typical highs of 14.1°C and lows of 5.2°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 84% — quite humid.
Average wind speed in May is 2.5 m/s. The windiest May on record averaged 3.4 m/s (1983).
The wettest May on record was 2016 with 162 mm. On average, May sees 78 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 Rolleston 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.
