May is one of the warmer months of the year in Belleville, with average highs near 23.9°C and lows around 12.6°C (mean 18.3°C). It is a relatively wet time of year, averaging 122 mm of rainfall and 78% relative humidity across the period.
May is one of the warmer months of the year in Belleville. Across 45 years of records, the warmest May in Belleville was 2018 — when the month averaged 22.5°C — while the coldest were 1981 and 1983 at 15.6°C. Typical May days reach 23.9°C with nights near 12.6°C. The long-term trend is warming, about 0.3°C per decade.
May is a relatively wet time of year in Belleville, averaging 122 mm of rainfall. The wettest May on record was 1995 with 306 mm, while the driest was 2005 at 37 mm.
Relative humidity in Belleville during May averages 78%. The most humid May was 1991 at 83%, and the least humid was 1988 at 72%.
May receives about 5.6 kWh/m²/day of solar energy in Belleville. The sunniest May was 2012 at 6.7 kWh/m²/day, and the cloudiest were 1995, 2003 and 2008, among others at 4.9.
Average wind speed in Belleville during May is 2.2 m/s. The windiest May was 1990 at 2.7 m/s, while the calmest was 1994 at 1.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 17.7°C | 17.9°C | 18.4°C | 19.0°C | 18.3°C | +0.6°C |
| Avg High | 23.6°C | 23.4°C | 24.1°C | 24.4°C | 23.8°C | +0.2°C |
| Avg Low | 11.7°C | 12.3°C | 12.6°C | 13.6°C | 13.0°C | +1.3°C |
| Avg Rain | 103 mm | 129 mm | 132 mm | 126 mm | 113 mm | +10 mm |
May temperatures in Belleville have risen by about 1.6°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 0.4°C (1983) to a record high of 33.3°C (2012).
Rainfall in May is a relatively wet time of year, averaging 122 mm, with a wettest year of 306 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.2°C per decade while lows rose 0.5°C per decade, narrowing the gap between day and night.
A good time to visit Belleville
May is a good time to visit Belleville, with days averaging 23.9°C and nights around 12.6°C (mean 18.3°C, warmer than Belleville's yearly average) and higher rainfall. September and June 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 | 22.5°C | 17.4°C | 12.3°C | 29.2°C | 6.9°C | 101 mm | 78% | 2.1 m/s | 5.5 |
| 2024 | 26.1°C | 20.7°C | 15.4°C | 31.0°C | 11.0°C | 158 mm | 78% | 2 m/s | 5.9 |
| 2023 | 25.1°C | 19.0°C | 12.9°C | 30.4°C | 4.3°C | 64 mm | 73% | 1.9 m/s | 6.4 |
| 2022 | 24.4°C | 19.2°C | 14.0°C | 30.8°C | 7.7°C | 137 mm | 81% | 2.5 m/s | 5.5 |
| 2021 | 22.3°C | 16.9°C | 11.6°C | 29.7°C | 3.3°C | 82 mm | 77% | 2.2 m/s | 5.2 |
| 2020 | 22.2°C | 16.9°C | 11.6°C | 29.1°C | 2.1°C | 135 mm | 81% | 2.2 m/s | 5.3 |
| 2019 | 24.0°C | 19.1°C | 14.1°C | 30.3°C | 6.4°C | 164 mm | 83% | 2.2 m/s | 5.4 |
| 2018 🔥 | 27.4°C | 22.5°C | 17.7°C | 32.3°C | 10.1°C | 106 mm | 80% | 1.8 m/s | 6 |
| 2017 | 23.5°C | 18.1°C | 12.7°C | 29.6°C | 5.4°C | 121 mm | 78% | 2.4 m/s | 6.1 |
| 2016 | 22.9°C | 17.4°C | 11.9°C | 29.7°C | 3.5°C | 123 mm | 78% | 2.1 m/s | 5.6 |
| 2015 | 24.2°C | 18.9°C | 13.7°C | 28.3°C | 5.1°C | 164 mm | 79% | 2.3 m/s | 5.6 |
| 2014 | 24.5°C | 18.9°C | 13.3°C | 29.4°C | 3.3°C | 82 mm | 78% | 2.1 m/s | 5.7 |
| 2013 | 23.6°C | 18.1°C | 12.6°C | 30.0°C | 2.0°C | 197 mm | 81% | 2.3 m/s | 5.3 |
| 2012 | 26.9°C | 20.8°C | 14.8°C | 33.3°C | 8.3°C | 38 mm | 72% | 1.9 m/s | 6.7 |
| 2011 | 23.0°C | 17.6°C | 12.2°C | 30.2°C | 2.1°C | 124 mm | 82% | 2.5 m/s | 5.2 |
| 2010 | 24.1°C | 18.7°C | 13.3°C | 29.8°C | 2.9°C | 145 mm | 81% | 2.1 m/s | 5.6 |
| 2009 | 23.4°C | 17.8°C | 12.3°C | 28.9°C | 4.2°C | 150 mm | 78% | 1.9 m/s | 5.6 |
| 2008 | 22.0°C | 16.4°C | 10.8°C | 29.6°C | 3.4°C | 206 mm | 81% | 2.5 m/s | 4.9 |
| 2007 | 25.6°C | 20.2°C | 14.8°C | 29.2°C | 5.7°C | 107 mm | 79% | 1.9 m/s | 5.7 |
| 2006 | 23.3°C | 17.8°C | 12.4°C | 31.1°C | 6.3°C | 95 mm | 77% | 2.2 m/s | 5.6 |
| 2005 | 23.8°C | 17.5°C | 11.2°C | 28.5°C | 1.2°C | 37 mm | 74% | 2 m/s | 6.6 |
| 2004 | 25.7°C | 20.3°C | 14.9°C | 30.9°C | 4.7°C | 182 mm | 81% | 2.3 m/s | 5.5 |
| 2003 | 23.2°C | 17.7°C | 12.2°C | 30.5°C | 5.9°C | 141 mm | 76% | 2.5 m/s | 4.9 |
| 2002 | 22.7°C | 16.7°C | 10.6°C | 30.5°C | 2.1°C | 171 mm | 78% | 2.4 m/s | 5.6 |
| 2001 | 25.2°C | 19.3°C | 13.3°C | 33.2°C | 6.4°C | 101 mm | 72% | 2.3 m/s | 5.5 |
| 2000 | 26.4°C | 20.1°C | 13.7°C | 32.6°C | 4.9°C | 133 mm | 73% | 2.5 m/s | 5.2 |
| 1999 | 24.0°C | 18.0°C | 12.0°C | 27.4°C | 7.0°C | 91 mm | 76% | 2.3 m/s | 6 |
| 1998 | 26.2°C | 20.8°C | 15.4°C | 31.0°C | 7.3°C | 95 mm | 80% | 2.1 m/s | 5.6 |
| 1997 | 21.8°C | 15.7°C | 9.5°C | 29.5°C | 4.3°C | 102 mm | 72% | 2.5 m/s | 5.8 |
| 1996 | 24.5°C | 19.2°C | 14.0°C | 31.1°C | 5.5°C | 136 mm | 81% | 2.3 m/s | 5.4 |
| 1995 🌧️ | 22.4°C | 17.1°C | 11.8°C | 28.8°C | 3.5°C | 306 mm | 80% | 2.2 m/s | 4.9 |
| 1994 | 22.5°C | 16.3°C | 10.1°C | 30.1°C | 1.6°C | 45 mm | 77% | 1.7 m/s | 6.4 |
| 1993 | 22.7°C | 17.6°C | 12.6°C | 28.9°C | 6.3°C | 107 mm | 81% | 2.2 m/s | 5.2 |
| 1992 | 22.2°C | 16.4°C | 10.6°C | 27.1°C | 1.1°C | 54 mm | 75% | 2 m/s | 5.7 |
| 1991 | 25.8°C | 21.1°C | 16.4°C | 31.1°C | 5.1°C | 87 mm | 83% | 1.8 m/s | 5.2 |
| 1990 | 22.2°C | 16.3°C | 10.5°C | 28.8°C | 3.3°C | 264 mm | 79% | 2.7 m/s | 4.9 |
| 1989 | 22.5°C | 16.3°C | 10.1°C | 30.9°C | 0.4°C | 98 mm | 74% | 2.2 m/s | 5.6 |
| 1988 | 24.8°C | 18.2°C | 11.5°C | 30.3°C | 4.5°C | 44 mm | 72% | 2.1 m/s | 6.6 |
| 1987 | 26.9°C | 21.0°C | 15.0°C | 30.7°C | 6.7°C | 45 mm | 75% | 1.9 m/s | 6.6 |
| 1986 | 24.0°C | 18.7°C | 13.3°C | 28.4°C | 4.5°C | 106 mm | 78% | 1.8 m/s | 5.4 |
| 1985 | 23.5°C | 17.9°C | 12.2°C | 29.4°C | 5.7°C | 68 mm | 79% | 2.4 m/s | 5.7 |
| 1984 | 22.0°C | 15.9°C | 9.8°C | 28.3°C | 3.4°C | 103 mm | 78% | 2.3 m/s | 5.7 |
| 1983 | 21.4°C | 15.6°C | 9.8°C | 26.1°C | 0.4°C | 133 mm | 80% | 2.5 m/s | — |
| 1982 | 25.9°C | 20.1°C | 14.3°C | 29.4°C | 7.8°C | 132 mm | 77% | 2 m/s | — |
| 1981 ❄️ | 21.5°C | 15.6°C | 9.7°C | 27.7°C | 3.2°C | 199 mm | 75% | 2.4 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 23.9°C with lows near 12.6°C (mean 18.3°C), based on 45 years of NASA POWER data.
May averages 122 mm of rainfall in Belleville, a relatively wet time of year. The wettest on record was 306 mm in 1995.
The hottest May reached 33.3°C in 2012. The coldest dipped to 0.4°C in 1983.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.6°C. Daytime highs moved from 22.9°C to 24.1°C and overnight lows from 11.2°C to 13.2°C over the same span.
May is one of the warmer months of the year in Belleville and a relatively wet time of year, so plan for around 23.9°C daytime highs and 12.6°C at night.
Not quite — May is the 8th coolest month in Belleville, averaging 18.3°C.
For May in Belleville, pack light layers you can adjust through the day, with typical highs of 23.9°C and lows of 12.6°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 78% — quite humid.
Average wind speed in May is 2.2 m/s. The windiest May on record averaged 2.7 m/s (1990).
The wettest May on record was 1995 with 306 mm. On average, May sees 122 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 Belleville 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.
