May is one of the warmer months of the year in Bolingbrook, with average highs near 21.4°C and lows around 9.2°C (mean 15.3°C). It is a relatively wet time of year, averaging 108 mm of rainfall and 76% relative humidity across the period.
May is one of the warmer months of the year in Bolingbrook. Across 45 years of records, the warmest May in Bolingbrook was 2018 — when the month averaged 18.9°C — while the coldest was 1997 at 12.1°C. Typical May days reach 21.4°C with nights near 9.2°C. The long-term trend is warming, about 0.3°C per decade.
May is a relatively wet time of year in Bolingbrook, averaging 108 mm of rainfall. The wettest May on record was 2019 with 196 mm, while the driest was 1992 at 19 mm.
Relative humidity in Bolingbrook during May averages 76%. The most humid May was 1991 at 83%, and the least humid was 1988 at 68%.
May receives about 5.5 kWh/m²/day of solar energy in Bolingbrook. The sunniest May was 1994 at 6.7 kWh/m²/day, and the cloudiest was 1996 at 4.4.
Average wind speed in Bolingbrook during May is 3.3 m/s. The windiest May was 1997 at 3.8 m/s, while the calmest were 1982, 1994 and 2018 at 2.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 14.9°C | 14.8°C | 15.2°C | 16.0°C | 15.8°C | +0.9°C |
| Avg High | 21.2°C | 20.8°C | 21.4°C | 22.0°C | 21.8°C | +0.6°C |
| Avg Low | 8.6°C | 8.9°C | 9.0°C | 10.1°C | 9.7°C | +1.1°C |
| Avg Rain | 100 mm | 108 mm | 105 mm | 125 mm | 96 mm | -4 mm |
May temperatures in Bolingbrook have risen by about 1.6°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -2.6°C (2020) to a record high of 33.4°C (2018).
Rainfall in May is a relatively wet time of year, averaging 108 mm, with a wettest year of 196 mm.
A good time to visit Bolingbrook
May is a good time to visit Bolingbrook, with days averaging 21.4°C and nights around 9.2°C (mean 15.3°C, warmer than Bolingbrook's yearly average) and higher rainfall. August and July 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 | 21.3°C | 15.0°C | 8.6°C | 30.1°C | 2.6°C | 56 mm | 73% | 3.3 m/s | 5.7 |
| 2024 | 23.7°C | 17.4°C | 11.1°C | 29.3°C | 7.0°C | 107 mm | 75% | 3.1 m/s | 6.3 |
| 2023 | 23.1°C | 16.2°C | 9.2°C | 31.3°C | 0.5°C | 51 mm | 68% | 2.9 m/s | 6.2 |
| 2022 | 22.1°C | 16.7°C | 11.2°C | 30.8°C | 3.5°C | 100 mm | 79% | 3.5 m/s | 4.9 |
| 2021 | 20.6°C | 14.9°C | 9.2°C | 30.4°C | 0.8°C | 92 mm | 71% | 3 m/s | 5.4 |
| 2020 | 19.8°C | 14.3°C | 8.8°C | 29.0°C | -2.6°C | 168 mm | 80% | 3 m/s | 5.5 |
| 2019 🌧️ | 20.5°C | 14.7°C | 8.9°C | 26.7°C | 3.1°C | 196 mm | 81% | 3.2 m/s | 4.8 |
| 2018 🔥 | 25.0°C | 18.9°C | 12.9°C | 33.4°C | 6.5°C | 110 mm | 79% | 2.8 m/s | 5.7 |
| 2017 | 19.8°C | 14.1°C | 8.4°C | 28.3°C | 1.0°C | 102 mm | 79% | 3.6 m/s | 5.6 |
| 2016 | 21.2°C | 15.3°C | 9.5°C | 28.7°C | -0.1°C | 110 mm | 75% | 3.1 m/s | 5.8 |
| 2015 | 22.6°C | 16.7°C | 10.7°C | 28.1°C | 1.7°C | 124 mm | 76% | 3.4 m/s | 5.2 |
| 2014 | 21.6°C | 15.5°C | 9.4°C | 29.4°C | 2.7°C | 96 mm | 75% | 3.3 m/s | 5.7 |
| 2013 | 21.9°C | 16.3°C | 10.7°C | 29.0°C | 0.3°C | 133 mm | 79% | 3.1 m/s | 5.3 |
| 2012 | 24.2°C | 17.8°C | 11.4°C | 33.3°C | 5.4°C | 97 mm | 72% | 3.2 m/s | 6.3 |
| 2011 | 20.6°C | 14.9°C | 9.3°C | 30.6°C | 0.3°C | 141 mm | 81% | 3.5 m/s | 4.9 |
| 2010 | 22.2°C | 16.2°C | 10.2°C | 31.0°C | 0.4°C | 145 mm | 78% | 3.2 m/s | 5.4 |
| 2009 | 20.7°C | 14.7°C | 8.6°C | 27.6°C | 0.7°C | 114 mm | 78% | 3.1 m/s | 5.8 |
| 2008 | 19.1°C | 13.1°C | 7.0°C | 26.4°C | 1.4°C | 105 mm | 76% | 3.6 m/s | 5.3 |
| 2007 | 23.4°C | 17.1°C | 10.8°C | 29.3°C | 3.3°C | 45 mm | 75% | 3.2 m/s | 5.9 |
| 2006 | 21.4°C | 15.5°C | 9.7°C | 31.4°C | 3.4°C | 98 mm | 75% | 3 m/s | 5.4 |
| 2005 | 20.9°C | 14.4°C | 8.0°C | 27.0°C | -2.2°C | 48 mm | 71% | 3.2 m/s | 5.7 |
| 2004 | 22.7°C | 16.7°C | 10.7°C | 29.9°C | -0.3°C | 164 mm | 78% | 3.5 m/s | 5.1 |
| 2003 | 21.1°C | 14.6°C | 8.0°C | 28.5°C | 1.7°C | 124 mm | 73% | 3.7 m/s | 5.4 |
| 2002 | 19.4°C | 12.9°C | 6.4°C | 29.6°C | -0.6°C | 122 mm | 77% | 3.5 m/s | 5.3 |
| 2001 | 22.1°C | 16.0°C | 9.9°C | 31.1°C | 4.5°C | 104 mm | 73% | 3.4 m/s | 5.2 |
| 2000 | 23.4°C | 17.1°C | 10.7°C | 29.3°C | 3.1°C | 127 mm | 74% | 3.4 m/s | 4.6 |
| 1999 | 22.8°C | 16.6°C | 10.4°C | 28.0°C | 4.0°C | 103 mm | 75% | 3.5 m/s | 5.7 |
| 1998 | 23.9°C | 18.0°C | 12.1°C | 30.3°C | 6.1°C | 111 mm | 78% | 3 m/s | 5.9 |
| 1997 ❄️ | 18.4°C | 12.1°C | 5.7°C | 26.5°C | 1.2°C | 85 mm | 72% | 3.8 m/s | 5.5 |
| 1996 | 19.9°C | 13.7°C | 7.5°C | 30.4°C | 0.4°C | 191 mm | 78% | 3.4 m/s | 4.4 |
| 1995 | 19.3°C | 13.9°C | 8.6°C | 25.5°C | 3.2°C | 148 mm | 77% | 3.2 m/s | 4.9 |
| 1994 | 20.5°C | 13.7°C | 7.0°C | 27.5°C | 0.1°C | 29 mm | 73% | 2.8 m/s | 6.7 |
| 1993 | 20.8°C | 15.0°C | 9.3°C | 27.1°C | 2.3°C | 74 mm | 79% | 3.3 m/s | 5.2 |
| 1992 | 20.4°C | 13.9°C | 7.3°C | 27.9°C | 0.2°C | 19 mm | 70% | 3 m/s | 6.1 |
| 1991 | 23.4°C | 18.4°C | 13.5°C | 30.1°C | 2.9°C | 151 mm | 83% | 2.9 m/s | 5.2 |
| 1990 | 18.8°C | 13.0°C | 7.2°C | 24.2°C | 1.0°C | 165 mm | 77% | 3.7 m/s | 5 |
| 1989 | 20.2°C | 13.9°C | 7.5°C | 28.6°C | -2.3°C | 107 mm | 71% | 3.3 m/s | 5.5 |
| 1988 | 22.9°C | 15.5°C | 8.1°C | 29.8°C | 1.9°C | 42 mm | 68% | 3.2 m/s | 6.6 |
| 1987 | 23.8°C | 17.5°C | 11.2°C | 28.9°C | 2.5°C | 127 mm | 75% | 3.1 m/s | 5.9 |
| 1986 | 21.3°C | 15.3°C | 9.3°C | 28.3°C | 1.2°C | 103 mm | 77% | 3.2 m/s | 5.1 |
| 1985 | 22.2°C | 16.0°C | 9.8°C | 28.5°C | 3.4°C | 58 mm | 73% | 3.7 m/s | 5.8 |
| 1984 | 19.1°C | 12.9°C | 6.6°C | 26.7°C | 0.9°C | 117 mm | 76% | 3.5 m/s | 5.2 |
| 1983 | 18.2°C | 12.4°C | 6.5°C | 23.8°C | -1.7°C | 120 mm | 79% | 3.5 m/s | — |
| 1982 | 24.1°C | 18.1°C | 12.2°C | 28.0°C | 6.8°C | 110 mm | 78% | 2.8 m/s | — |
| 1981 | 18.9°C | 12.6°C | 6.4°C | 26.7°C | -1.1°C | 118 mm | 74% | 3.5 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 21.4°C with lows near 9.2°C (mean 15.3°C), based on 45 years of NASA POWER data.
May averages 108 mm of rainfall in Bolingbrook, a relatively wet time of year. The wettest on record was 196 mm in 2019.
The hottest May reached 33.4°C in 2018. The coldest dipped to -2.6°C in 2020.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.6°C. Daytime highs moved from 20.5°C to 22.2°C and overnight lows from 8.3°C to 9.9°C over the same span.
May is one of the warmer months of the year in Bolingbrook and a relatively wet time of year, so plan for around 21.4°C daytime highs and 9.2°C at night.
Not quite — May is the 8th coolest month in Bolingbrook, averaging 15.3°C.
For May in Bolingbrook, pack light layers you can adjust through the day, with typical highs of 21.4°C and lows of 9.2°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 76% — quite humid.
Average wind speed in May is 3.3 m/s. The windiest May on record averaged 3.8 m/s (1997).
The wettest May on record was 2019 with 196 mm. On average, May sees 108 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 Bolingbrook 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.
