May is one of the warmer months of the year in Simcoe, with average highs near 19.3°C and lows around 7.5°C (mean 13.4°C). It is about average for rainfall, averaging 67 mm of rainfall and 72% relative humidity across the period.
May is one of the warmer months of the year in Simcoe. Across 45 years of records, the warmest May in Simcoe was 1998 — when the month averaged 17.2°C — while the coldest was 1997 at 9.3°C. Typical May days reach 19.3°C with nights near 7.5°C. The long-term trend is warming, about 0.3°C per decade.
May is about average for rainfall in Simcoe, averaging 67 mm of rainfall. The wettest May on record was 2004 with 151 mm, while the driest was 2021 at 22 mm.
Relative humidity in Simcoe during May averages 72%. The most humid May was 2011 at 85%, and the least humid was 2021 at 59%.
May receives about 5.6 kWh/m²/day of solar energy in Simcoe. The sunniest May was 2023 at 6.5 kWh/m²/day, and the cloudiest was 1984 at 4.5.
Average wind speed in Simcoe during May is 3.1 m/s. The windiest May was 1997 at 4 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 | 13.1°C | 13.3°C | 12.4°C | 14.2°C | 14.2°C | +1.1°C |
| Avg High | 18.9°C | 19.5°C | 18.1°C | 20.0°C | 20.3°C | +1.4°C |
| Avg Low | 7.4°C | 7.2°C | 6.8°C | 8.5°C | 8.1°C | +0.7°C |
| Avg Rain | 65 mm | 54 mm | 85 mm | 78 mm | 40 mm | -25 mm |
May temperatures in Simcoe have risen by about 2.4°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -3.3°C (1986) to a record high of 32.1°C (1988).
Rainfall in May is about average for rainfall, averaging 67 mm, with a wettest year of 151 mm.
A good time to visit Simcoe
May is a good time to visit Simcoe, with days averaging 19.3°C and nights around 7.5°C (mean 13.4°C, warmer than Simcoe's yearly average) and moderate 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 | 19.2°C | 13.8°C | 8.3°C | 28.4°C | 2.2°C | 44 mm | 70% | 3.6 m/s | 5.1 |
| 2024 | 22.7°C | 16.6°C | 10.5°C | 28.9°C | 5.3°C | 57 mm | 70% | 2.8 m/s | 5.8 |
| 2023 | 20.4°C | 13.7°C | 7.0°C | 30.3°C | 1.3°C | 26 mm | 62% | 2.7 m/s | 6.5 |
| 2022 | 21.3°C | 15.2°C | 9.1°C | 30.0°C | 1.4°C | 51 mm | 70% | 3 m/s | 5.8 |
| 2021 | 20.5°C | 14.0°C | 7.6°C | 30.4°C | -1.2°C | 22 mm | 59% | 3 m/s | 5.9 |
| 2020 | 17.7°C | 12.0°C | 6.3°C | 29.8°C | -3.3°C | 40 mm | 73% | 3.2 m/s | 5.5 |
| 2019 | 18.2°C | 12.2°C | 6.2°C | 25.4°C | 0.6°C | 82 mm | 80% | 3 m/s | 4.7 |
| 2018 | 22.2°C | 15.8°C | 9.4°C | 31.0°C | 1.8°C | 69 mm | 75% | 3 m/s | 5.9 |
| 2017 | 17.2°C | 12.3°C | 7.4°C | 26.3°C | -0.9°C | 113 mm | 79% | 3.4 m/s | 5.5 |
| 2016 | 19.3°C | 13.6°C | 8.0°C | 30.2°C | 0.8°C | 43 mm | 72% | 2.7 m/s | 6.1 |
| 2015 | 22.0°C | 15.6°C | 9.2°C | 28.0°C | 1.2°C | 66 mm | 70% | 3 m/s | 5.7 |
| 2014 | 18.9°C | 13.3°C | 7.8°C | 24.8°C | 0.1°C | 81 mm | 77% | 2.9 m/s | 5.5 |
| 2013 | 20.5°C | 14.5°C | 8.5°C | 27.4°C | 0.4°C | 87 mm | 74% | 3.1 m/s | 6.1 |
| 2012 | 23.2°C | 16.8°C | 10.3°C | 30.5°C | 2.9°C | 54 mm | 67% | 2.6 m/s | 6.3 |
| 2011 | 17.7°C | 13.0°C | 8.3°C | 27.4°C | 1.8°C | 114 mm | 85% | 3 m/s | 5 |
| 2010 | 20.9°C | 15.1°C | 9.4°C | 30.9°C | -0.9°C | 72 mm | 72% | 3.1 m/s | 5.7 |
| 2009 | 18.9°C | 12.6°C | 6.4°C | 24.5°C | -1.3°C | 65 mm | 73% | 3.2 m/s | 6.2 |
| 2008 | 17.2°C | 11.4°C | 5.6°C | 24.0°C | -0.4°C | 59 mm | 74% | 3.2 m/s | 5.4 |
| 2007 | 20.6°C | 14.1°C | 7.6°C | 29.5°C | 0.9°C | 31 mm | 68% | 2.7 m/s | 6.2 |
| 2006 | 19.9°C | 14.2°C | 8.4°C | 30.6°C | 1.6°C | 55 mm | 72% | 2.9 m/s | 5.7 |
| 2005 | 16.8°C | 11.3°C | 5.8°C | 24.4°C | -1.2°C | 32 mm | 73% | 2.7 m/s | 6.2 |
| 2004 🌧️ | 18.5°C | 13.0°C | 7.4°C | 26.5°C | -2.8°C | 151 mm | 83% | 3.1 m/s | 5.3 |
| 2003 | 16.6°C | 11.4°C | 6.3°C | 22.1°C | 0.5°C | 128 mm | 81% | 3.2 m/s | 5 |
| 2002 | 15.0°C | 9.6°C | 4.1°C | 23.3°C | -2.2°C | 103 mm | 79% | 3.5 m/s | 5.3 |
| 2001 | 19.2°C | 13.5°C | 7.8°C | 24.6°C | 1.0°C | 104 mm | 76% | 2.9 m/s | 5.3 |
| 2000 | 18.4°C | 13.3°C | 8.2°C | 24.8°C | 3.6°C | 124 mm | 81% | 3.5 m/s | 5 |
| 1999 | 21.0°C | 14.6°C | 8.2°C | 29.2°C | 2.5°C | 57 mm | 68% | 3 m/s | 6.1 |
| 1998 🔥 | 23.5°C | 17.2°C | 11.0°C | 30.2°C | 5.6°C | 33 mm | 67% | 2.9 m/s | 6 |
| 1997 ❄️ | 15.1°C | 9.3°C | 3.6°C | 21.8°C | -1.6°C | 79 mm | 71% | 4 m/s | 5.2 |
| 1996 | 17.5°C | 11.6°C | 5.7°C | 25.7°C | -1.4°C | 54 mm | 69% | 3.3 m/s | 5.6 |
| 1995 | 19.7°C | 13.5°C | 7.3°C | 26.1°C | 1.3°C | 33 mm | 63% | 3.3 m/s | 5.5 |
| 1994 | 18.7°C | 12.2°C | 5.8°C | 29.7°C | 0.2°C | 42 mm | 66% | 3.4 m/s | 5.5 |
| 1993 | 19.6°C | 13.2°C | 6.9°C | 28.4°C | 2.6°C | 46 mm | 65% | 3.3 m/s | 5.2 |
| 1992 | 20.2°C | 13.4°C | 6.6°C | 27.9°C | 1.3°C | 31 mm | 63% | 2.7 m/s | 6.1 |
| 1991 | 22.3°C | 16.4°C | 10.6°C | 29.5°C | 1.1°C | 61 mm | 74% | 3.1 m/s | 5.6 |
| 1990 | 17.1°C | 11.5°C | 5.9°C | 22.5°C | 0.7°C | 103 mm | 71% | 3.6 m/s | 5.3 |
| 1989 | 18.5°C | 13.1°C | 7.7°C | 26.7°C | 0.9°C | 54 mm | 70% | 3.4 m/s | 5 |
| 1988 | 21.0°C | 14.5°C | 8.0°C | 32.1°C | 1.8°C | 45 mm | 66% | 3.1 m/s | 5.9 |
| 1987 | 21.9°C | 15.3°C | 8.7°C | 31.2°C | 0.7°C | 42 mm | 65% | 3.4 m/s | 6.3 |
| 1986 | 19.4°C | 13.9°C | 8.5°C | 27.2°C | -3.3°C | 81 mm | 77% | 3.3 m/s | 5.6 |
| 1985 | 19.0°C | 13.4°C | 7.8°C | 24.6°C | 2.2°C | 59 mm | 76% | 3.5 m/s | 6.3 |
| 1984 | 14.8°C | 9.8°C | 4.8°C | 23.7°C | -1.0°C | 71 mm | 80% | 3.7 m/s | 4.5 |
| 1983 | 15.9°C | 10.2°C | 4.4°C | 21.4°C | -2.4°C | 104 mm | 79% | 3.5 m/s | — |
| 1982 | 20.6°C | 14.9°C | 9.3°C | 26.2°C | 3.4°C | 86 mm | 77% | 2.4 m/s | — |
| 1981 | 19.2°C | 13.1°C | 7.0°C | 27.4°C | 0.5°C | 46 mm | 66% | 2.7 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 19.3°C with lows near 7.5°C (mean 13.4°C), based on 45 years of NASA POWER data.
May averages 67 mm of rainfall in Simcoe, about average for rainfall. The wettest on record was 151 mm in 2004.
The hottest May reached 32.1°C in 1988. The coldest dipped to -3.3°C in 1986.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 2.4°C. Daytime highs moved from 17.9°C to 20.8°C and overnight lows from 6.7°C to 8.5°C over the same span.
May is one of the warmer months of the year in Simcoe and about average for rainfall, so plan for around 19.3°C daytime highs and 7.5°C at night.
Not quite — May is the 8th coolest month in Simcoe, averaging 13.4°C.
For May in Simcoe, pack warm layers and a jacket for chilly mornings, with typical highs of 19.3°C and lows of 7.5°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 72% — moderately humid.
Average wind speed in May is 3.1 m/s. The windiest May on record averaged 4 m/s (1997).
The wettest May on record was 2004 with 151 mm. On average, May sees 67 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 Simcoe 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.
