May is one of the warmer months of the year in Windsor, with average highs near 19.5°C and lows around 7.9°C (mean 13.7°C). It is a relatively wet time of year, averaging 84 mm of rainfall and 75% relative humidity across the period.
May is one of the warmer months of the year in Windsor. Across 45 years of records, the warmest May in Windsor was 1991 — when the month averaged 16.9°C — while the coldest was 1997 at 9.4°C. Typical May days reach 19.5°C with nights near 7.9°C. The long-term trend is warming, about 0.4°C per decade.
May is a relatively wet time of year in Windsor, averaging 84 mm of rainfall. The wettest May on record was 2004 with 192 mm, while the driest was 1988 at 25 mm.
Relative humidity in Windsor during May averages 75%. The most humid May was 2011 at 82%, and the least humid was 2023 at 66%.
May receives about 5.6 kWh/m²/day of solar energy in Windsor. The sunniest May was 2023 at 6.4 kWh/m²/day, and the cloudiest were 1984 and 2019 at 4.6.
Average wind speed in Windsor during May is 3.2 m/s. The windiest May was 1997 at 3.9 m/s, while the calmest was 1982 at 2.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 13.3°C | 13.2°C | 13.3°C | 14.7°C | 14.3°C | +1°C |
| Avg High | 19.3°C | 19.0°C | 19.0°C | 20.4°C | 20.1°C | +0.8°C |
| Avg Low | 7.4°C | 7.3°C | 7.6°C | 9.0°C | 8.4°C | +1°C |
| Avg Rain | 79 mm | 67 mm | 98 mm | 102 mm | 69 mm | -9 mm |
May temperatures in Windsor have risen by about 1.8°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -3.2°C (2020) to a record high of 31.1°C (2018).
Rainfall in May is a relatively wet time of year, averaging 84 mm, with a wettest year of 192 mm.
A good time to visit Windsor
May is a good time to visit Windsor, with days averaging 19.5°C and nights around 7.9°C (mean 13.7°C, warmer than Windsor's yearly average) and higher rainfall. July and August 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 | 19.1°C | 13.6°C | 8.0°C | 26.0°C | 1.4°C | 87 mm | 75% | 3.4 m/s | 5.2 |
| 2024 | 22.4°C | 16.4°C | 10.4°C | 28.2°C | 4.8°C | 89 mm | 74% | 2.9 m/s | 5.9 |
| 2023 | 20.4°C | 13.6°C | 6.8°C | 28.9°C | 1.5°C | 26 mm | 66% | 2.8 m/s | 6.4 |
| 2022 | 21.0°C | 15.4°C | 9.8°C | 29.0°C | 0.9°C | 78 mm | 76% | 3.2 m/s | 5.7 |
| 2021 | 20.0°C | 14.0°C | 8.0°C | 29.6°C | 0.3°C | 49 mm | 66% | 2.8 m/s | 5.7 |
| 2020 | 17.9°C | 12.7°C | 7.4°C | 28.6°C | -3.2°C | 88 mm | 76% | 3.4 m/s | 5.7 |
| 2019 | 18.8°C | 13.0°C | 7.1°C | 24.8°C | 2.4°C | 87 mm | 80% | 3.1 m/s | 4.6 |
| 2018 | 22.7°C | 16.6°C | 10.4°C | 31.1°C | 4.0°C | 108 mm | 78% | 3 m/s | 5.8 |
| 2017 | 18.4°C | 13.0°C | 7.6°C | 27.4°C | -1.5°C | 103 mm | 76% | 3.6 m/s | 5.4 |
| 2016 | 19.7°C | 14.0°C | 8.3°C | 28.3°C | 1.7°C | 56 mm | 74% | 2.9 m/s | 6 |
| 2015 | 21.5°C | 15.5°C | 9.5°C | 27.0°C | 2.0°C | 109 mm | 75% | 3 m/s | 5.4 |
| 2014 | 19.9°C | 14.2°C | 8.5°C | 26.7°C | 1.8°C | 116 mm | 76% | 2.9 m/s | 5.4 |
| 2013 | 21.2°C | 15.4°C | 9.5°C | 28.0°C | -1.4°C | 74 mm | 75% | 3.2 m/s | 6.1 |
| 2012 | 21.9°C | 15.9°C | 10.0°C | 29.1°C | 4.2°C | 69 mm | 75% | 2.7 m/s | 6.2 |
| 2011 | 19.5°C | 14.1°C | 8.8°C | 29.2°C | 0.6°C | 158 mm | 82% | 3 m/s | 4.9 |
| 2010 | 20.8°C | 15.3°C | 9.8°C | 28.3°C | -0.6°C | 140 mm | 77% | 3.3 m/s | 5.7 |
| 2009 | 19.0°C | 13.1°C | 7.2°C | 25.3°C | 2.6°C | 71 mm | 74% | 3.3 m/s | 6 |
| 2008 | 18.0°C | 12.2°C | 6.4°C | 24.8°C | 1.7°C | 56 mm | 74% | 3.5 m/s | 5.5 |
| 2007 | 21.0°C | 14.8°C | 8.6°C | 28.9°C | 1.5°C | 77 mm | 72% | 3 m/s | 5.9 |
| 2006 | 19.4°C | 14.2°C | 9.0°C | 30.3°C | 1.7°C | 106 mm | 77% | 3.1 m/s | 5.7 |
| 2005 | 18.4°C | 12.5°C | 6.6°C | 25.0°C | -1.5°C | 35 mm | 70% | 3 m/s | 5.6 |
| 2004 🌧️ | 19.9°C | 14.1°C | 8.3°C | 26.2°C | -0.9°C | 192 mm | 80% | 3.2 m/s | 5 |
| 2003 | 17.8°C | 12.3°C | 6.7°C | 24.1°C | 1.0°C | 101 mm | 78% | 3.4 m/s | 4.9 |
| 2002 | 16.3°C | 10.7°C | 5.0°C | 25.2°C | -0.9°C | 84 mm | 76% | 3.6 m/s | 5.3 |
| 2001 | 19.9°C | 14.4°C | 9.0°C | 26.3°C | 2.8°C | 111 mm | 76% | 3.3 m/s | 5.2 |
| 2000 | 20.5°C | 15.1°C | 9.6°C | 27.4°C | 3.5°C | 147 mm | 75% | 3.5 m/s | 5 |
| 1999 | 21.4°C | 15.1°C | 8.7°C | 28.4°C | 2.7°C | 60 mm | 71% | 3.5 m/s | 5.9 |
| 1998 | 22.4°C | 16.6°C | 10.8°C | 28.1°C | 6.2°C | 41 mm | 76% | 3 m/s | 6 |
| 1997 ❄️ | 14.9°C | 9.4°C | 3.9°C | 21.4°C | 0.2°C | 108 mm | 76% | 3.9 m/s | 4.8 |
| 1996 | 17.5°C | 11.7°C | 5.9°C | 26.8°C | -2.1°C | 76 mm | 74% | 3.3 m/s | 5.3 |
| 1995 | 18.4°C | 12.8°C | 7.2°C | 23.9°C | 1.5°C | 77 mm | 74% | 3.2 m/s | 5.1 |
| 1994 | 18.2°C | 11.9°C | 5.6°C | 27.6°C | -0.6°C | 31 mm | 71% | 3.3 m/s | 5.9 |
| 1993 | 18.9°C | 13.0°C | 7.1°C | 25.3°C | 2.5°C | 43 mm | 74% | 3.2 m/s | 5.3 |
| 1992 | 18.9°C | 12.6°C | 6.2°C | 26.0°C | 0.4°C | 44 mm | 71% | 2.9 m/s | 5.9 |
| 1991 🔥 | 22.4°C | 16.9°C | 11.5°C | 28.6°C | 0.8°C | 97 mm | 79% | 2.9 m/s | 5.5 |
| 1990 | 17.4°C | 11.9°C | 6.4°C | 22.9°C | 1.2°C | 96 mm | 74% | 3.6 m/s | 5.6 |
| 1989 | 18.2°C | 12.6°C | 7.0°C | 26.7°C | 0.0°C | 119 mm | 73% | 3.2 m/s | 5.3 |
| 1988 | 20.9°C | 14.4°C | 7.9°C | 29.8°C | 2.1°C | 25 mm | 70% | 3 m/s | 6.3 |
| 1987 | 21.3°C | 15.1°C | 8.8°C | 28.6°C | 0.2°C | 69 mm | 74% | 2.8 m/s | 6.2 |
| 1986 | 19.6°C | 14.0°C | 8.3°C | 27.9°C | -2.9°C | 60 mm | 78% | 3.2 m/s | 5.8 |
| 1985 | 20.3°C | 14.2°C | 8.1°C | 26.0°C | 3.4°C | 74 mm | 75% | 3.4 m/s | 6.3 |
| 1984 | 16.7°C | 11.0°C | 5.2°C | 24.5°C | -1.0°C | 101 mm | 76% | 3.6 m/s | 4.6 |
| 1983 | 16.6°C | 10.7°C | 4.8°C | 21.6°C | -2.0°C | 106 mm | 76% | 3.5 m/s | — |
| 1982 | 21.7°C | 15.6°C | 9.6°C | 26.0°C | 2.8°C | 79 mm | 79% | 2.4 m/s | — |
| 1981 | 18.0°C | 12.3°C | 6.7°C | 25.2°C | 0.2°C | 76 mm | 73% | 3.1 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 19.5°C with lows near 7.9°C (mean 13.7°C), based on 45 years of NASA POWER data.
May averages 84 mm of rainfall in Windsor, a relatively wet time of year. The wettest on record was 192 mm in 2004.
The hottest May reached 31.1°C in 2018. The coldest dipped to -3.2°C in 2020.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.8°C. Daytime highs moved from 18.7°C to 20.6°C and overnight lows from 6.9°C to 8.6°C over the same span.
May is one of the warmer months of the year in Windsor and a relatively wet time of year, so plan for around 19.5°C daytime highs and 7.9°C at night.
Not quite — May is the 8th coolest month in Windsor, averaging 13.7°C.
For May in Windsor, pack warm layers and a jacket for chilly mornings, with typical highs of 19.5°C and lows of 7.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 75% — moderately humid.
Average wind speed in May is 3.2 m/s. The windiest May on record averaged 3.9 m/s (1997).
The wettest May on record was 2004 with 192 mm. On average, May sees 84 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 Windsor 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.
