May is one of the warmer months of the year in Granby, with average highs near 17.3°C and lows around 6.1°C (mean 11.7°C). It is about average for rainfall, averaging 95 mm of rainfall and 80% relative humidity across the period.
May is one of the warmer months of the year in Granby. Across 45 years of records, the warmest May in Granby was 1998 — when the month averaged 14.6°C — while the coldest was 1997 at 8.3°C. Typical May days reach 17.3°C with nights near 6.1°C. The long-term trend is warming, about 0.4°C per decade.
May is about average for rainfall in Granby, averaging 95 mm of rainfall. The wettest May on record was 2006 with 188 mm, while the driest was 1982 at 36 mm.
Relative humidity in Granby during May averages 80%. The most humid Mays were 2006 and 2011 at 85%, and the least humid was 2023 at 73%.
May receives about 5.3 kWh/m²/day of solar energy in Granby. The sunniest May was 2023 at 6.3 kWh/m²/day, and the cloudiest was 1984 at 4.
Average wind speed in Granby during May is 0.4 m/s. The windiest Mays were 2018, 2020 and 2023, among others at 0.4 m/s, while the calmest were 2022, 2024 and 2025, among others at 0.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 11.5°C | 11.2°C | 11.1°C | 12.6°C | 12.5°C | +1°C |
| Avg High | 17.0°C | 16.8°C | 16.6°C | 18.2°C | 18.3°C | +1.3°C |
| Avg Low | 6.0°C | 5.7°C | 5.6°C | 6.9°C | 6.8°C | +0.8°C |
| Avg Rain | 100 mm | 91 mm | 112 mm | 91 mm | 72 mm | -27 mm |
May temperatures in Granby have risen by about 2.1°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -4.3°C (1995) to a record high of 30.5°C (2020).
Rainfall in May is about average for rainfall, averaging 95 mm, with a wettest year of 188 mm.
A good time to visit Granby
May is a good time to visit Granby, with days averaging 17.3°C and nights around 6.1°C (mean 11.7°C, warmer than Granby'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 | 18.0°C | 12.7°C | 7.5°C | 26.7°C | -1.8°C | 123 mm | 81% | 0.3 m/s | 4.5 |
| 2024 | 19.7°C | 14.5°C | 9.3°C | 28.0°C | 1.8°C | 82 mm | 80% | 0.3 m/s | 5.2 |
| 2023 | 17.6°C | 11.3°C | 5.1°C | 28.5°C | -3.1°C | 49 mm | 73% | 0.4 m/s | 6.3 |
| 2022 | 20.2°C | 13.8°C | 7.4°C | 28.7°C | -1.9°C | 90 mm | 75% | 0.3 m/s | 5.9 |
| 2021 | 18.0°C | 12.2°C | 6.4°C | 28.1°C | -0.2°C | 37 mm | 74% | 0.3 m/s | 5.7 |
| 2020 | 16.4°C | 10.8°C | 5.2°C | 30.5°C | -3.1°C | 52 mm | 77% | 0.4 m/s | 6.2 |
| 2019 | 15.4°C | 10.1°C | 4.7°C | 23.2°C | -2.4°C | 106 mm | 80% | 0.3 m/s | 4.7 |
| 2018 | 19.1°C | 12.9°C | 6.6°C | 27.3°C | -0.9°C | 47 mm | 76% | 0.4 m/s | 5.9 |
| 2017 | 16.5°C | 11.5°C | 6.4°C | 28.0°C | -1.8°C | 97 mm | 81% | 0.4 m/s | 4.5 |
| 2016 | 17.7°C | 11.9°C | 6.0°C | 26.4°C | -2.0°C | 58 mm | 79% | 0.3 m/s | 5.5 |
| 2015 | 20.2°C | 14.1°C | 8.0°C | 27.6°C | -1.1°C | 85 mm | 77% | 0.4 m/s | 5.7 |
| 2014 | 17.5°C | 12.1°C | 6.7°C | 26.5°C | -1.5°C | 95 mm | 82% | 0.3 m/s | 5.2 |
| 2013 | 19.2°C | 13.2°C | 7.1°C | 26.7°C | -1.8°C | 123 mm | 78% | 0.4 m/s | 5.4 |
| 2012 | 19.3°C | 14.0°C | 8.6°C | 29.1°C | 2.3°C | 101 mm | 81% | 0.3 m/s | 5.4 |
| 2011 | 17.9°C | 12.8°C | 7.6°C | 27.3°C | -1.2°C | 149 mm | 85% | 0.3 m/s | 4.6 |
| 2010 | 19.0°C | 13.0°C | 6.9°C | 28.4°C | -2.3°C | 45 mm | 78% | 0.3 m/s | 5.9 |
| 2009 | 16.3°C | 10.8°C | 5.2°C | 25.1°C | -1.2°C | 114 mm | 80% | 0.4 m/s | 5 |
| 2008 | 15.8°C | 10.3°C | 4.8°C | 21.9°C | -2.8°C | 69 mm | 78% | 0.3 m/s | 5.6 |
| 2007 | 16.9°C | 11.0°C | 5.2°C | 26.9°C | -1.4°C | 88 mm | 80% | 0.4 m/s | 5.8 |
| 2006 🌧️ | 17.5°C | 12.7°C | 7.9°C | 27.6°C | -0.3°C | 188 mm | 85% | 0.3 m/s | 4.6 |
| 2005 | 14.2°C | 9.4°C | 4.6°C | 23.6°C | -3.8°C | 70 mm | 82% | 0.4 m/s | 5 |
| 2004 | 17.6°C | 12.0°C | 6.4°C | 25.6°C | -3.6°C | 119 mm | 81% | 0.4 m/s | 5 |
| 2003 | 17.0°C | 11.3°C | 5.5°C | 26.0°C | -2.1°C | 121 mm | 80% | 0.3 m/s | 5.1 |
| 2002 | 15.0°C | 9.6°C | 4.3°C | 24.4°C | -0.8°C | 130 mm | 79% | 0.4 m/s | 4.8 |
| 2001 | 19.0°C | 12.9°C | 6.8°C | 25.6°C | 0.6°C | 63 mm | 80% | 0.3 m/s | 5.3 |
| 2000 | 16.6°C | 11.1°C | 5.6°C | 25.4°C | -1.4°C | 158 mm | 82% | 0.3 m/s | 4.8 |
| 1999 | 20.3°C | 14.0°C | 7.7°C | 28.1°C | -1.0°C | 76 mm | 76% | 0.4 m/s | 5.9 |
| 1998 🔥 | 20.5°C | 14.6°C | 8.7°C | 26.6°C | 4.4°C | 68 mm | 79% | 0.3 m/s | 5.7 |
| 1997 ❄️ | 13.1°C | 8.3°C | 3.4°C | 23.0°C | -3.3°C | 102 mm | 82% | 0.4 m/s | 4.6 |
| 1996 | 15.2°C | 10.0°C | 4.8°C | 24.4°C | -0.9°C | 96 mm | 79% | 0.4 m/s | 5.8 |
| 1995 | 16.6°C | 11.0°C | 5.4°C | 23.7°C | -4.3°C | 101 mm | 79% | 0.4 m/s | 5.1 |
| 1994 | 16.1°C | 10.2°C | 4.4°C | 25.8°C | -3.0°C | 128 mm | 81% | 0.4 m/s | 5.2 |
| 1993 | 16.5°C | 11.4°C | 6.3°C | 22.7°C | 0.9°C | 96 mm | 82% | 0.4 m/s | 4.7 |
| 1992 | 17.1°C | 10.8°C | 4.6°C | 26.2°C | -1.4°C | 49 mm | 78% | 0.4 m/s | 6.1 |
| 1991 | 17.9°C | 12.6°C | 7.3°C | 26.3°C | 0.8°C | 99 mm | 81% | 0.4 m/s | 5.3 |
| 1990 | 15.0°C | 9.5°C | 4.1°C | 22.4°C | -1.5°C | 96 mm | 80% | 0.4 m/s | 4.9 |
| 1989 | 18.0°C | 12.9°C | 7.9°C | 26.7°C | 1.8°C | 123 mm | 83% | 0.4 m/s | 4.5 |
| 1988 | 18.1°C | 12.3°C | 6.5°C | 22.9°C | 1.0°C | 47 mm | 80% | 0.3 m/s | 5.1 |
| 1987 | 17.2°C | 11.2°C | 5.3°C | 27.0°C | -2.6°C | 90 mm | 77% | 0.4 m/s | 5.4 |
| 1986 | 18.2°C | 12.7°C | 7.2°C | 25.4°C | -3.7°C | 115 mm | 81% | 0.4 m/s | 5.1 |
| 1985 | 16.1°C | 10.5°C | 4.9°C | 24.7°C | -3.2°C | 70 mm | 79% | 0.4 m/s | 5.6 |
| 1984 | 14.2°C | 9.6°C | 5.0°C | 23.2°C | -1.4°C | 138 mm | 82% | 0.4 m/s | 4 |
| 1983 | 14.9°C | 9.7°C | 4.4°C | 21.3°C | -1.1°C | 173 mm | 84% | 0.3 m/s | — |
| 1982 | 18.6°C | 12.4°C | 6.3°C | 28.5°C | 0.9°C | 36 mm | 79% | 0.3 m/s | — |
| 1981 | 17.7°C | 11.9°C | 6.1°C | 23.6°C | -2.3°C | 104 mm | 80% | 0.3 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 17.3°C with lows near 6.1°C (mean 11.7°C), based on 45 years of NASA POWER data.
May averages 95 mm of rainfall in Granby, about average for rainfall. The wettest on record was 188 mm in 2006.
The hottest May reached 30.5°C in 2020. The coldest dipped to -4.3°C in 1995.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 2.1°C. Daytime highs moved from 16.3°C to 18.7°C and overnight lows from 5.3°C to 7.1°C over the same span.
May is one of the warmer months of the year in Granby and about average for rainfall, so plan for around 17.3°C daytime highs and 6.1°C at night.
Not quite — May is the 8th coolest month in Granby, averaging 11.7°C.
For May in Granby, pack warm layers and a jacket for chilly mornings, with typical highs of 17.3°C and lows of 6.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 80% — quite humid.
Average wind speed in May is 0.4 m/s. The windiest May on record averaged 0.4 m/s (1984).
The wettest May on record was 2006 with 188 mm. On average, May sees 95 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 Granby 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.
