May is one of the warmer months of the year in Oakville, with average highs near 14.8°C and lows around 7.4°C (mean 11.1°C). It is about average for rainfall, averaging 64 mm of rainfall and 77% relative humidity across the period.
May is one of the warmer months of the year in Oakville. Across 45 years of records, the warmest May in Oakville was 1998 — when the month averaged 15°C — while the coldest was 2002 at 7.5°C. Typical May days reach 14.8°C with nights near 7.4°C. The long-term trend is warming, about 0.6°C per decade.
May is about average for rainfall in Oakville, averaging 64 mm of rainfall. The wettest May on record was 2003 with 134 mm, while the driest was 2005 at 22 mm.
Relative humidity in Oakville during May averages 77%. The most humid May was 2011 at 87%, and the least humid was 2021 at 68%.
May receives about 5.5 kWh/m²/day of solar energy in Oakville. The sunniest May was 2023 at 6.3 kWh/m²/day, and the cloudiest was 1984 at 4.4.
Average wind speed in Oakville during May is 3 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 | 10.3°C | 10.6°C | 10.5°C | 12.2°C | 12.2°C | +1.9°C |
| Avg High | 14.2°C | 14.6°C | 14.0°C | 15.8°C | 15.8°C | +1.6°C |
| Avg Low | 6.5°C | 6.6°C | 7.0°C | 8.6°C | 8.7°C | +2.2°C |
| Avg Rain | 57 mm | 56 mm | 84 mm | 69 mm | 43 mm | -14 mm |
May temperatures in Oakville have risen by about 3°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -1.3°C (1986) to a record high of 28.5°C (2010).
Rainfall in May is about average for rainfall, averaging 64 mm, with a wettest year of 134 mm.
A good time to visit Oakville
May is a good time to visit Oakville, with days averaging 14.8°C and nights around 7.4°C (mean 11.1°C, warmer than Oakville's yearly average) and moderate 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 | 14.4°C | 11.1°C | 7.9°C | 22.4°C | 4.3°C | 65 mm | 79% | 3.4 m/s | 5 |
| 2024 | 18.0°C | 14.5°C | 11.0°C | 24.3°C | 6.3°C | 49 mm | 77% | 2.7 m/s | 5.7 |
| 2023 | 16.3°C | 12.2°C | 8.2°C | 26.6°C | 4.0°C | 29 mm | 68% | 2.7 m/s | 6.3 |
| 2022 | 16.2°C | 12.7°C | 9.2°C | 23.7°C | 4.3°C | 47 mm | 76% | 2.9 m/s | 5.7 |
| 2021 | 16.2°C | 12.3°C | 8.4°C | 24.0°C | 1.6°C | 24 mm | 68% | 3 m/s | 5.7 |
| 2020 | 13.8°C | 10.5°C | 7.2°C | 25.6°C | 0.0°C | 44 mm | 75% | 3.4 m/s | 5.4 |
| 2019 | 13.2°C | 9.7°C | 6.2°C | 19.2°C | 2.5°C | 78 mm | 84% | 3 m/s | 4.6 |
| 2018 | 17.5°C | 13.2°C | 8.9°C | 28.0°C | 4.0°C | 54 mm | 79% | 2.9 m/s | 6.1 |
| 2017 | 13.3°C | 10.5°C | 7.7°C | 19.3°C | 3.3°C | 130 mm | 83% | 3.4 m/s | 5 |
| 2016 | 16.3°C | 12.6°C | 8.9°C | 26.5°C | 2.7°C | 42 mm | 75% | 2.8 m/s | 6 |
| 2015 | 17.0°C | 12.8°C | 8.5°C | 23.4°C | 3.1°C | 46 mm | 74% | 3 m/s | 5.8 |
| 2014 | 14.5°C | 11.0°C | 7.5°C | 20.6°C | 2.5°C | 65 mm | 81% | 2.8 m/s | 5.4 |
| 2013 | 16.6°C | 12.8°C | 9.1°C | 23.3°C | 2.8°C | 67 mm | 76% | 3.2 m/s | 6.1 |
| 2012 | 18.5°C | 14.7°C | 10.9°C | 25.7°C | 5.0°C | 36 mm | 73% | 2.5 m/s | 6 |
| 2011 | 13.9°C | 11.1°C | 8.2°C | 22.7°C | 3.7°C | 111 mm | 87% | 3.1 m/s | 4.5 |
| 2010 | 17.3°C | 13.7°C | 10.1°C | 28.5°C | 1.9°C | 62 mm | 76% | 3.1 m/s | 5.7 |
| 2009 | 14.4°C | 10.7°C | 7.0°C | 19.7°C | 2.5°C | 65 mm | 77% | 3.3 m/s | 6.1 |
| 2008 | 13.5°C | 10.0°C | 6.5°C | 18.4°C | 2.9°C | 65 mm | 77% | 3.3 m/s | 5.3 |
| 2007 | 16.6°C | 12.6°C | 8.7°C | 26.4°C | 3.7°C | 47 mm | 72% | 2.5 m/s | 6.2 |
| 2006 | 16.1°C | 12.8°C | 9.4°C | 28.0°C | 4.1°C | 58 mm | 76% | 3 m/s | 5.5 |
| 2005 | 14.1°C | 10.6°C | 7.0°C | 22.5°C | 1.4°C | 22 mm | 74% | 2.6 m/s | 5.9 |
| 2004 | 13.7°C | 10.4°C | 7.0°C | 22.4°C | 0.2°C | 119 mm | 86% | 2.9 m/s | 4.9 |
| 2003 🌧️ | 11.7°C | 8.5°C | 5.2°C | 18.3°C | 1.9°C | 134 mm | 84% | 2.9 m/s | 4.8 |
| 2002 ❄️ | 11.1°C | 7.5°C | 3.9°C | 18.2°C | -0.4°C | 104 mm | 81% | 3.6 m/s | 5.1 |
| 2001 | 14.4°C | 10.6°C | 6.7°C | 20.1°C | 1.9°C | 108 mm | 79% | 2.8 m/s | 5.6 |
| 2000 | 14.5°C | 11.3°C | 8.1°C | 19.7°C | 4.3°C | 121 mm | 83% | 3.3 m/s | 4.9 |
| 1999 | 16.4°C | 12.6°C | 8.7°C | 24.7°C | 4.8°C | 50 mm | 72% | 3 m/s | 6.1 |
| 1998 🔥 | 18.8°C | 15.0°C | 11.3°C | 26.0°C | 8.5°C | 42 mm | 75% | 2.9 m/s | 5.8 |
| 1997 | 11.7°C | 8.3°C | 4.9°C | 18.4°C | 0.8°C | 54 mm | 75% | 3.9 m/s | 4.9 |
| 1996 | 12.5°C | 8.6°C | 4.8°C | 19.2°C | -0.5°C | 59 mm | 75% | 2.9 m/s | 5.6 |
| 1995 | 14.7°C | 10.5°C | 6.3°C | 21.6°C | 1.1°C | 36 mm | 70% | 3 m/s | 5.4 |
| 1994 | 13.4°C | 9.2°C | 4.9°C | 24.7°C | 0.3°C | 71 mm | 73% | 3 m/s | 5.3 |
| 1993 | 13.7°C | 9.6°C | 5.6°C | 22.5°C | 2.2°C | 47 mm | 72% | 2.9 m/s | 5.1 |
| 1992 | 14.0°C | 9.8°C | 5.7°C | 21.9°C | 2.0°C | 47 mm | 73% | 2.5 m/s | 6.1 |
| 1991 | 17.1°C | 12.9°C | 8.7°C | 25.7°C | 1.0°C | 58 mm | 78% | 2.9 m/s | 5.5 |
| 1990 | 13.2°C | 9.2°C | 5.2°C | 18.9°C | 0.3°C | 93 mm | 74% | 3.2 m/s | 5 |
| 1989 | 13.7°C | 10.0°C | 6.3°C | 22.2°C | 1.6°C | 55 mm | 76% | 3.1 m/s | 4.9 |
| 1988 | 15.6°C | 11.2°C | 6.8°C | 27.2°C | 2.4°C | 36 mm | 71% | 2.9 m/s | 5.8 |
| 1987 | 16.3°C | 11.9°C | 7.6°C | 25.0°C | 1.6°C | 26 mm | 72% | 3.2 m/s | 5.9 |
| 1986 | 15.1°C | 11.5°C | 7.9°C | 23.4°C | -1.3°C | 58 mm | 79% | 3.3 m/s | 5.4 |
| 1985 | 14.3°C | 10.5°C | 6.8°C | 19.8°C | 1.8°C | 56 mm | 78% | 3.2 m/s | 5.7 |
| 1984 | 10.9°C | 7.6°C | 4.3°C | 16.3°C | -0.3°C | 69 mm | 82% | 3.5 m/s | 4.4 |
| 1983 | 12.0°C | 8.3°C | 4.6°C | 17.8°C | -0.8°C | 88 mm | 82% | 3.3 m/s | — |
| 1982 | 15.5°C | 11.5°C | 7.6°C | 21.2°C | 4.0°C | 56 mm | 79% | 2.4 m/s | — |
| 1981 | 14.3°C | 10.3°C | 6.3°C | 22.5°C | 1.3°C | 70 mm | 73% | 2.6 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 14.8°C with lows near 7.4°C (mean 11.1°C), based on 45 years of NASA POWER data.
May averages 64 mm of rainfall in Oakville, about average for rainfall. The wettest on record was 134 mm in 2003.
The hottest May reached 28.5°C in 2010. The coldest dipped to -1.3°C in 1986.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 3°C. Daytime highs moved from 13.4°C to 16.2°C and overnight lows from 5.9°C to 8.9°C over the same span.
May is one of the warmer months of the year in Oakville and about average for rainfall, so plan for around 14.8°C daytime highs and 7.4°C at night.
Not quite — May is the 8th coolest month in Oakville, averaging 11.1°C.
For May in Oakville, pack warm layers and a jacket for chilly mornings, with typical highs of 14.8°C and lows of 7.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 77% — quite humid.
Average wind speed in May is 3 m/s. The windiest May on record averaged 3.9 m/s (1997).
The wettest May on record was 2003 with 134 mm. On average, May sees 64 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 Oakville 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.
