May is one of the warmer months of the year in Calgary, with average highs near 15.2°C and lows around 2.1°C (mean 8.7°C). It is a relatively wet time of year, averaging 74 mm of rainfall and 63% relative humidity across the period.
May is one of the warmer months of the year in Calgary. Across 45 years of records, the warmest May in Calgary was 2023 — when the month averaged 13.4°C — while the coldest was 1996 at 5.1°C. Typical May days reach 15.2°C with nights near 2.1°C. The long-term May temperature trend is broadly flat.
May is a relatively wet time of year in Calgary, averaging 74 mm of rainfall. The wettest May on record was 1981 with 145 mm, while the driest was 1987 at 16 mm.
Relative humidity in Calgary during May averages 63%. The most humid May was 1981 at 73%, and the least humid was 1988 at 50%.
May receives about 5.4 kWh/m²/day of solar energy in Calgary. The sunniest Mays were 2015, 2023 and 2025 at 6 kWh/m²/day, and the cloudiest was 2004 at 4.7.
Average wind speed in Calgary during May is 1.2 m/s. The windiest May was 2001 at 1.5 m/s, while the calmest were 2014, 2023 and 2025, among others at 1.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 8.9°C | 8.6°C | 8.2°C | 8.7°C | 9.2°C | +0.3°C |
| Avg High | 15.6°C | 15.1°C | 14.7°C | 15.1°C | 15.8°C | +0.2°C |
| Avg Low | 2.3°C | 2.0°C | 1.7°C | 2.2°C | 2.6°C | +0.3°C |
| Avg Rain | 60 mm | 85 mm | 67 mm | 74 mm | 88 mm | +28 mm |
May temperatures in Calgary have risen by about 1.3°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -9.5°C (2002) to a record high of 32.6°C (1986).
Rainfall in May is a relatively wet time of year, averaging 74 mm, with a wettest year of 145 mm.
A good time to visit Calgary
May is a good time to visit Calgary, with days averaging 15.2°C and nights around 2.1°C (mean 8.7°C, warmer than Calgary'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 | 17.9°C | 10.8°C | 3.6°C | 28.5°C | -2.2°C | 68 mm | 63% | 1.1 m/s | 6 |
| 2024 | 13.6°C | 7.7°C | 1.9°C | 24.7°C | -4.6°C | 87 mm | 68% | 1.3 m/s | 5.1 |
| 2023 🔥 | 20.8°C | 13.4°C | 6.1°C | 26.9°C | 1.2°C | 32 mm | 61% | 1.1 m/s | 6 |
| 2022 | 13.3°C | 7.1°C | 0.8°C | 19.6°C | -3.9°C | 123 mm | 65% | 1.2 m/s | 5.7 |
| 2021 | 14.4°C | 7.9°C | 1.5°C | 25.7°C | -3.5°C | 121 mm | 63% | 1.2 m/s | 5.3 |
| 2020 | 14.6°C | 8.2°C | 1.8°C | 22.4°C | -4.1°C | 96 mm | 66% | 1.2 m/s | 4.9 |
| 2019 | 13.9°C | 7.8°C | 1.7°C | 24.4°C | -5.4°C | 75 mm | 69% | 1.2 m/s | 4.8 |
| 2018 | 18.8°C | 12.2°C | 5.5°C | 26.4°C | -0.4°C | 69 mm | 65% | 1.3 m/s | 5.9 |
| 2017 | 16.9°C | 10.2°C | 3.5°C | 25.3°C | -2.2°C | 69 mm | 64% | 1.2 m/s | 5.6 |
| 2016 | 16.6°C | 9.7°C | 2.8°C | 26.6°C | -2.2°C | 72 mm | 58% | 1.3 m/s | 5.5 |
| 2015 | 15.0°C | 8.3°C | 1.6°C | 23.1°C | -4.1°C | 40 mm | 60% | 1.2 m/s | 6 |
| 2014 | 13.6°C | 7.4°C | 1.2°C | 22.0°C | -5.9°C | 86 mm | 68% | 1.1 m/s | 5 |
| 2013 | 16.1°C | 9.7°C | 3.3°C | 25.3°C | -7.5°C | 108 mm | 63% | 1.3 m/s | 5.3 |
| 2012 | 14.5°C | 8.0°C | 1.5°C | 25.4°C | -3.0°C | 49 mm | 59% | 1.2 m/s | 5.6 |
| 2011 | 13.3°C | 7.1°C | 0.8°C | 19.6°C | -4.0°C | 110 mm | 67% | 1.3 m/s | 5.2 |
| 2010 | 12.1°C | 6.2°C | 0.3°C | 24.3°C | -5.5°C | 60 mm | 62% | 1.3 m/s | 4.8 |
| 2009 | 14.7°C | 7.9°C | 1.2°C | 25.4°C | -5.4°C | 46 mm | 60% | 1.2 m/s | 5.8 |
| 2008 | 14.9°C | 8.7°C | 2.4°C | 27.1°C | -3.3°C | 133 mm | 69% | 1.2 m/s | 4.9 |
| 2007 | 15.4°C | 8.9°C | 2.3°C | 23.1°C | -2.0°C | 106 mm | 66% | 1.2 m/s | 5.5 |
| 2006 | 16.7°C | 10.1°C | 3.4°C | 28.3°C | -3.8°C | 51 mm | 62% | 1.2 m/s | 5.7 |
| 2005 | 16.1°C | 9.3°C | 2.4°C | 21.5°C | -6.0°C | 50 mm | 62% | 1.3 m/s | 5.9 |
| 2004 | 12.8°C | 6.7°C | 0.6°C | 22.1°C | -6.0°C | 100 mm | 68% | 1.2 m/s | 4.7 |
| 2003 | 13.3°C | 7.4°C | 1.4°C | 26.7°C | -4.8°C | 52 mm | 66% | 1.1 m/s | 5 |
| 2002 | 11.9°C | 5.5°C | -0.9°C | 21.8°C | -9.5°C | 78 mm | 67% | 1.4 m/s | 5 |
| 2001 | 17.3°C | 10.2°C | 3.2°C | 29.1°C | -2.5°C | 21 mm | 50% | 1.5 m/s | 5.7 |
| 2000 | 14.1°C | 7.6°C | 1.1°C | 20.0°C | -3.4°C | 38 mm | 59% | 1.2 m/s | 5.5 |
| 1999 | 14.1°C | 7.8°C | 1.5°C | 26.8°C | -5.7°C | 55 mm | 59% | 1.3 m/s | 5.4 |
| 1998 | 18.3°C | 11.4°C | 4.5°C | 25.2°C | 0.7°C | 104 mm | 62% | 1.3 m/s | 5.8 |
| 1997 | 14.6°C | 8.1°C | 1.5°C | 24.4°C | -6.1°C | 109 mm | 65% | 1.3 m/s | 5.5 |
| 1996 ❄️ | 11.0°C | 5.1°C | -0.8°C | 22.5°C | -7.6°C | 79 mm | 71% | 1.2 m/s | 5.1 |
| 1995 | 14.7°C | 8.0°C | 1.3°C | 26.8°C | -4.6°C | 95 mm | 66% | 1.2 m/s | 5.3 |
| 1994 | 16.4°C | 9.7°C | 2.9°C | 25.0°C | -2.3°C | 59 mm | 62% | 1.1 m/s | 5 |
| 1993 | 17.4°C | 10.5°C | 3.6°C | 27.3°C | -3.2°C | 75 mm | 64% | 1.3 m/s | 5.1 |
| 1992 | 16.4°C | 9.1°C | 1.8°C | 27.3°C | -6.5°C | 67 mm | 59% | 1.3 m/s | 5.3 |
| 1991 | 14.1°C | 8.0°C | 2.0°C | 22.8°C | -4.2°C | 87 mm | 66% | 1.1 m/s | 5 |
| 1990 | 14.1°C | 8.0°C | 1.9°C | 25.3°C | -3.4°C | 117 mm | 69% | 1.2 m/s | 5 |
| 1989 | 15.1°C | 8.4°C | 1.7°C | 22.9°C | -3.2°C | 43 mm | 57% | 1.3 m/s | 5.3 |
| 1988 | 18.2°C | 11.0°C | 3.8°C | 28.9°C | -3.3°C | 32 mm | 50% | 1.3 m/s | 5.4 |
| 1987 | 18.2°C | 10.7°C | 3.3°C | 27.0°C | -4.5°C | 16 mm | 52% | 1.3 m/s | 5.7 |
| 1986 | 16.4°C | 9.7°C | 3.1°C | 32.6°C | -5.9°C | 68 mm | 64% | 1.2 m/s | 5.3 |
| 1985 | 17.2°C | 10.2°C | 3.1°C | 26.9°C | -2.5°C | 62 mm | 60% | 1.2 m/s | 5.7 |
| 1984 | 12.9°C | 6.7°C | 0.5°C | 24.4°C | -3.7°C | 62 mm | 62% | 1.4 m/s | 4.9 |
| 1983 | 14.9°C | 8.4°C | 1.9°C | 25.6°C | -4.0°C | 37 mm | 65% | 1.2 m/s | — |
| 1982 | 13.5°C | 6.9°C | 0.3°C | 24.4°C | -5.7°C | 78 mm | 64% | 1.3 m/s | — |
| 1981 🌧️ | 13.6°C | 8.2°C | 2.8°C | 21.1°C | -1.9°C | 145 mm | 73% | 1.2 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 15.2°C with lows near 2.1°C (mean 8.7°C), based on 45 years of NASA POWER data.
May averages 74 mm of rainfall in Calgary, a relatively wet time of year. The wettest on record was 145 mm in 1981.
The hottest May reached 32.6°C in 1986. The coldest dipped to -9.5°C in 2002.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.3°C. Daytime highs moved from 14.4°C to 16°C and overnight lows from 1.7°C to 2.8°C over the same span.
May is one of the warmer months of the year in Calgary and a relatively wet time of year, so plan for around 15.2°C daytime highs and 2.1°C at night.
Not quite — May is the 8th coolest month in Calgary, averaging 8.7°C.
For May in Calgary, pack warm layers and a jacket for chilly mornings, with typical highs of 15.2°C and lows of 2.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 63% — moderately humid.
Average wind speed in May is 1.2 m/s. The windiest May on record averaged 1.5 m/s (2001).
The wettest May on record was 1981 with 145 mm. On average, May sees 74 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 Calgary 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.
