May is one of the cooler months of the year in Grafton, with average highs near 21.3°C and lows around 15.1°C (mean 18.2°C). It is about average for rainfall, averaging 114 mm of rainfall and 75% relative humidity across the period.
May is one of the cooler months of the year in Grafton. Across 45 years of records, the warmest Mays in Grafton were 2007 and 2016 — when the month averaged 20.3°C — while the coldest was 1984 at 16.8°C. Typical May days reach 21.3°C with nights near 15.1°C. The long-term May temperature trend is broadly flat.
May is about average for rainfall in Grafton, averaging 114 mm of rainfall. The wettest May on record was 1996 with 519 mm, while the driest was 2004 at 11 mm.
Relative humidity in Grafton during May averages 75%. The most humid May was 1990 at 83%, and the least humid was 2016 at 62%.
May receives about 3.4 kWh/m²/day of solar energy in Grafton. The sunniest May was 2006 at 4.1 kWh/m²/day, and the cloudiest was 2022 at 2.6.
Average wind speed in Grafton during May is 2.5 m/s. The windiest May was 1996 at 3.5 m/s, while the calmest was 1982 at 1.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 17.9°C | 18.2°C | 18.3°C | 18.3°C | 18.2°C | +0.3°C |
| Avg High | 20.8°C | 21.1°C | 21.6°C | 21.8°C | 21.1°C | +0.3°C |
| Avg Low | 15.0°C | 15.3°C | 14.9°C | 14.9°C | 15.4°C | +0.4°C |
| Avg Rain | 139 mm | 162 mm | 94 mm | 69 mm | 104 mm | -35 mm |
May temperatures in Grafton have risen by about 0.7°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 7°C (2000) to a record high of 29.7°C (2007).
Rainfall in May is about average for rainfall, averaging 114 mm, with a wettest year of 519 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.2°C per decade while lows rose 0°C per decade, widening the gap between day and night.
A good time to visit Grafton
May is a good time to visit Grafton, with days averaging 21.3°C and nights around 15.1°C (mean 18.2°C, cooler than Grafton's yearly average) and higher rainfall. November and October 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 | 21.5°C | 19.1°C | 16.6°C | 23.8°C | 11.8°C | 212 mm | 81% | 2.8 m/s | 3.1 |
| 2024 | 21.0°C | 18.5°C | 16.0°C | 22.5°C | 11.8°C | 111 mm | 80% | 2.5 m/s | 3.2 |
| 2023 | 21.9°C | 17.7°C | 13.6°C | 26.1°C | 9.3°C | 41 mm | 64% | 2.5 m/s | 3.9 |
| 2022 | 20.9°C | 18.8°C | 16.8°C | 25.3°C | 10.9°C | 139 mm | 82% | 2.6 m/s | 2.6 |
| 2021 | 20.5°C | 17.6°C | 14.8°C | 23.3°C | 10.2°C | 75 mm | 78% | 2.1 m/s | 3.5 |
| 2020 | 20.5°C | 17.4°C | 14.3°C | 23.5°C | 9.5°C | 49 mm | 75% | 2.7 m/s | 3.5 |
| 2019 | 23.0°C | 19.1°C | 15.2°C | 26.6°C | 8.6°C | 37 mm | 67% | 2.2 m/s | 3.5 |
| 2018 | 22.4°C | 18.8°C | 15.1°C | 26.2°C | 11.5°C | 33 mm | 68% | 2.4 m/s | 3.8 |
| 2017 | 21.2°C | 18.2°C | 15.3°C | 24.1°C | 10.5°C | 62 mm | 80% | 2 m/s | 3.3 |
| 2016 | 24.9°C | 20.3°C | 15.6°C | 28.0°C | 10.4°C | 18 mm | 62% | 2 m/s | 3.9 |
| 2015 | 21.0°C | 17.9°C | 14.8°C | 24.9°C | 10.1°C | 187 mm | 78% | 2.3 m/s | 3.4 |
| 2014 | 22.0°C | 18.7°C | 15.4°C | 26.4°C | 9.7°C | 54 mm | 72% | 2.1 m/s | 3.4 |
| 2013 | 20.2°C | 17.4°C | 14.6°C | 25.3°C | 10.1°C | 120 mm | 76% | 2.5 m/s | 3.3 |
| 2012 | 21.0°C | 17.4°C | 13.9°C | 25.5°C | 10.3°C | 48 mm | 73% | 2.1 m/s | 3.8 |
| 2011 | 20.2°C | 17.0°C | 13.7°C | 22.9°C | 10.2°C | 51 mm | 75% | 2.7 m/s | 3.6 |
| 2010 | 22.0°C | 18.6°C | 15.2°C | 26.8°C | 11.7°C | 76 mm | 72% | 2.6 m/s | 3.4 |
| 2009 | 20.2°C | 17.9°C | 15.5°C | 22.3°C | 11.5°C | 309 mm | 77% | 2.9 m/s | 3.1 |
| 2008 | 21.2°C | 17.6°C | 13.9°C | 25.0°C | 10.3°C | 52 mm | 73% | 2.4 m/s | 3.8 |
| 2007 🔥 | 24.0°C | 20.3°C | 16.6°C | 29.7°C | 12.8°C | 36 mm | 70% | 2.1 m/s | 3.6 |
| 2006 | 21.6°C | 17.7°C | 13.9°C | 25.8°C | 10.1°C | 27 mm | 66% | 2.1 m/s | 4.1 |
| 2005 | 21.8°C | 18.5°C | 15.2°C | 28.2°C | 11.5°C | 93 mm | 71% | 3.2 m/s | 3.5 |
| 2004 | 22.5°C | 18.3°C | 14.0°C | 24.7°C | 9.8°C | 11 mm | 64% | 2.2 m/s | 4 |
| 2003 | 21.0°C | 18.1°C | 15.2°C | 26.3°C | 11.8°C | 158 mm | 77% | 2.7 m/s | 3.5 |
| 2002 | 22.0°C | 18.5°C | 15.1°C | 26.2°C | 10.8°C | 59 mm | 69% | 2.5 m/s | 3.4 |
| 2001 | 20.3°C | 17.3°C | 14.3°C | 24.8°C | 10.1°C | 113 mm | 78% | 2.7 m/s | 3.5 |
| 2000 | 21.4°C | 18.3°C | 15.1°C | 25.2°C | 7.0°C | 80 mm | 74% | 2.7 m/s | 3.5 |
| 1999 | 21.1°C | 18.5°C | 15.9°C | 24.0°C | 12.4°C | 154 mm | 81% | 2.6 m/s | 3 |
| 1998 | 22.2°C | 18.7°C | 15.2°C | 25.0°C | 11.1°C | 80 mm | 72% | 2.3 m/s | 3.4 |
| 1997 | 20.8°C | 18.1°C | 15.3°C | 24.7°C | 11.1°C | 151 mm | 81% | 3 m/s | 3.1 |
| 1996 🌧️ | 20.3°C | 18.0°C | 15.8°C | 24.6°C | 11.1°C | 519 mm | 81% | 3.5 m/s | 3.1 |
| 1995 | 21.1°C | 18.4°C | 15.6°C | 26.6°C | 9.4°C | 133 mm | 77% | 2.7 m/s | 3.2 |
| 1994 | 21.4°C | 17.5°C | 13.5°C | 25.9°C | 8.4°C | 82 mm | 70% | 2.3 m/s | 3.9 |
| 1993 | 22.0°C | 18.9°C | 15.8°C | 26.4°C | 13.2°C | 49 mm | 74% | 2.6 m/s | 3.6 |
| 1992 | 20.2°C | 17.6°C | 15.0°C | 23.7°C | 11.6°C | 88 mm | 79% | 2.2 m/s | 3.2 |
| 1991 | 21.5°C | 18.7°C | 15.9°C | 28.7°C | 14.6°C | 131 mm | 77% | 2.8 m/s | 3.1 |
| 1990 | 20.8°C | 18.1°C | 15.4°C | 23.7°C | 10.7°C | 237 mm | 83% | 2.4 m/s | 3.4 |
| 1989 | 20.9°C | 18.7°C | 16.5°C | 24.3°C | 11.6°C | 135 mm | 83% | 2.4 m/s | 3 |
| 1988 | 20.7°C | 17.8°C | 15.0°C | 23.6°C | 10.7°C | 31 mm | 79% | 2.3 m/s | 3.5 |
| 1987 | 20.3°C | 17.6°C | 14.8°C | 23.9°C | 7.6°C | 269 mm | 80% | 2.5 m/s | 3 |
| 1986 | 21.9°C | 18.7°C | 15.5°C | 25.9°C | 11.3°C | 114 mm | 75% | 2.8 m/s | 3.4 |
| 1985 | 20.1°C | 17.6°C | 15.2°C | 24.2°C | 10.6°C | 211 mm | 82% | 3.1 m/s | 3.2 |
| 1984 ❄️ | 19.8°C | 16.8°C | 13.9°C | 22.9°C | 10.2°C | 80 mm | 76% | 2 m/s | 3.7 |
| 1983 | 20.6°C | 17.9°C | 15.3°C | 22.6°C | 9.7°C | 213 mm | 80% | 2.1 m/s | — |
| 1982 | 22.2°C | 18.3°C | 14.5°C | 25.7°C | 10.6°C | 57 mm | 68% | 1.9 m/s | — |
| 1981 | 20.4°C | 17.4°C | 14.4°C | 23.7°C | 10.9°C | 141 mm | 77% | 2.7 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 21.3°C with lows near 15.1°C (mean 18.2°C), based on 45 years of NASA POWER data.
May averages 114 mm of rainfall in Grafton, about average for rainfall. The wettest on record was 519 mm in 1996.
The hottest May reached 29.7°C in 2007. The coldest dipped to 7°C in 2000.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 0.7°C. Daytime highs moved from 20.6°C to 21.2°C and overnight lows from 14.7°C to 15.6°C over the same span.
May is one of the cooler months of the year in Grafton and about average for rainfall, so plan for around 21.3°C daytime highs and 15.1°C at night.
Not quite — May is the 4th coolest month in Grafton, averaging 18.2°C.
For May in Grafton, pack light layers you can adjust through the day, with typical highs of 21.3°C and lows of 15.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 75% — quite humid.
Average wind speed in May is 2.5 m/s. The windiest May on record averaged 3.5 m/s (1996).
The wettest May on record was 1996 with 519 mm. On average, May sees 114 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 Grafton 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.
