May is one of the warmer months of the year in Trail, with average highs near 15.1°C and lows around 3.3°C (mean 9.2°C). It is about average for rainfall, averaging 71 mm of rainfall and 71% relative humidity across the period.
May is one of the warmer months of the year in Trail. Across 45 years of records, the warmest May in Trail was 2023 — when the month averaged 13.9°C — while the coldest was 1984 at 5.8°C. Typical May days reach 15.1°C with nights near 3.3°C. The long-term trend is warming, about 0.2°C per decade.
May is about average for rainfall in Trail, averaging 71 mm of rainfall. The wettest May on record was 1998 with 154 mm, while the driest was 1992 at 27 mm.
Relative humidity in Trail during May averages 71%. The most humid May was 1996 at 80%, and the least humid was 2001 at 59%.
May receives about 5.2 kWh/m²/day of solar energy in Trail. The sunniest Mays were 1995 and 2015 at 6 kWh/m²/day, and the cloudiest was 2022 at 4.
Average wind speed in Trail during May is 0.3 m/s. The windiest Mays were 2018, 2021 and 2023, among others at 0.3 m/s, while the calmest were 2022, 2024 and 2025, among others at 0.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 8.8°C | 9.3°C | 8.9°C | 9.7°C | 9.4°C | +0.6°C |
| Avg High | 14.7°C | 15.1°C | 14.9°C | 15.6°C | 15.2°C | +0.5°C |
| Avg Low | 3.0°C | 3.5°C | 3.0°C | 3.7°C | 3.6°C | +0.6°C |
| Avg Rain | 63 mm | 87 mm | 59 mm | 68 mm | 81 mm | +17 mm |
May temperatures in Trail have risen by about 1.1°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -4.9°C (1986) to a record high of 30.2°C (1983).
Rainfall in May is about average for rainfall, averaging 71 mm, with a wettest year of 154 mm.
A good time to visit Trail
May is a good time to visit Trail, with days averaging 15.1°C and nights around 3.3°C (mean 9.2°C, warmer than Trail'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 | 15.8°C | 9.6°C | 3.5°C | 25.1°C | -3.9°C | 63 mm | 72% | 0.2 m/s | 5.6 |
| 2024 | 13.7°C | 7.9°C | 2.2°C | 22.3°C | -3.2°C | 63 mm | 75% | 0.2 m/s | 5 |
| 2023 🔥 | 19.8°C | 13.9°C | 8.1°C | 29.5°C | 4.0°C | 94 mm | 74% | 0.3 m/s | 5.6 |
| 2022 | 11.8°C | 6.8°C | 1.7°C | 17.0°C | -2.0°C | 98 mm | 78% | 0.2 m/s | 4 |
| 2021 | 15.5°C | 9.2°C | 2.9°C | 24.4°C | -3.2°C | 34 mm | 65% | 0.3 m/s | 5.5 |
| 2020 | 14.7°C | 8.9°C | 3.1°C | 24.5°C | -2.5°C | 132 mm | 76% | 0.2 m/s | 4.8 |
| 2019 | 16.7°C | 10.9°C | 5.0°C | 23.9°C | -0.7°C | 52 mm | 69% | 0.2 m/s | 5.3 |
| 2018 | 19.1°C | 12.9°C | 6.8°C | 25.0°C | -0.9°C | 47 mm | 71% | 0.3 m/s | 5.7 |
| 2017 | 15.8°C | 9.9°C | 4.1°C | 26.0°C | -1.1°C | 67 mm | 72% | 0.3 m/s | 5.4 |
| 2016 | 16.1°C | 10.1°C | 4.1°C | 22.8°C | 0.4°C | 93 mm | 72% | 0.2 m/s | 5.5 |
| 2015 | 17.2°C | 10.5°C | 3.7°C | 24.2°C | -2.4°C | 41 mm | 68% | 0.3 m/s | 6 |
| 2014 | 15.2°C | 9.7°C | 4.2°C | 21.5°C | -1.9°C | 75 mm | 71% | 0.3 m/s | 5.1 |
| 2013 | 16.5°C | 10.1°C | 3.8°C | 24.4°C | -2.7°C | 89 mm | 69% | 0.3 m/s | 5.5 |
| 2012 | 13.9°C | 8.1°C | 2.3°C | 24.6°C | -4.8°C | 52 mm | 68% | 0.2 m/s | 5.4 |
| 2011 | 13.0°C | 7.3°C | 1.6°C | 19.1°C | -3.7°C | 84 mm | 75% | 0.2 m/s | 5 |
| 2010 | 12.4°C | 7.1°C | 1.8°C | 21.1°C | -3.0°C | 78 mm | 71% | 0.3 m/s | 4.6 |
| 2009 | 15.0°C | 8.7°C | 2.3°C | 24.6°C | -2.8°C | 54 mm | 67% | 0.3 m/s | 5.6 |
| 2008 | 15.5°C | 9.3°C | 3.1°C | 24.4°C | -3.0°C | 45 mm | 71% | 0.3 m/s | 5.2 |
| 2007 | 15.7°C | 9.7°C | 3.7°C | 24.3°C | -2.3°C | 45 mm | 66% | 0.3 m/s | 5.7 |
| 2006 | 15.7°C | 9.9°C | 4.2°C | 28.2°C | -4.6°C | 74 mm | 68% | 0.3 m/s | 5.4 |
| 2005 | 16.3°C | 10.2°C | 4.1°C | 26.4°C | -0.9°C | 61 mm | 69% | 0.2 m/s | 5.3 |
| 2004 | 14.7°C | 9.0°C | 3.3°C | 21.7°C | -0.7°C | 67 mm | 71% | 0.2 m/s | 4.8 |
| 2003 | 13.3°C | 7.9°C | 2.5°C | 24.9°C | -3.0°C | 49 mm | 73% | 0.3 m/s | 4.6 |
| 2002 | 12.5°C | 7.1°C | 1.7°C | 21.0°C | -4.2°C | 85 mm | 73% | 0.2 m/s | 4.6 |
| 2001 | 16.7°C | 9.8°C | 3.0°C | 28.0°C | -3.4°C | 45 mm | 59% | 0.3 m/s | 5.8 |
| 2000 | 13.1°C | 7.5°C | 2.0°C | 19.5°C | -2.3°C | 64 mm | 72% | 0.3 m/s | 5 |
| 1999 | 12.5°C | 7.0°C | 1.6°C | 25.3°C | -2.9°C | 68 mm | 72% | 0.2 m/s | 5.1 |
| 1998 🌧️ | 16.5°C | 10.7°C | 4.9°C | 22.9°C | -0.4°C | 154 mm | 73% | 0.2 m/s | 5.7 |
| 1997 | 15.4°C | 9.7°C | 4.0°C | 22.6°C | -1.4°C | 70 mm | 73% | 0.3 m/s | 5.5 |
| 1996 | 11.1°C | 6.3°C | 1.5°C | 20.0°C | -3.0°C | 145 mm | 80% | 0.2 m/s | 4.2 |
| 1995 | 16.3°C | 10.0°C | 3.8°C | 24.3°C | -1.9°C | 35 mm | 66% | 0.3 m/s | 6 |
| 1994 | 16.0°C | 10.1°C | 4.2°C | 23.7°C | 0.1°C | 67 mm | 69% | 0.3 m/s | 5 |
| 1993 | 18.7°C | 12.0°C | 5.3°C | 27.7°C | -2.9°C | 58 mm | 68% | 0.3 m/s | 5.5 |
| 1992 | 17.4°C | 10.7°C | 4.1°C | 25.6°C | -2.9°C | 27 mm | 60% | 0.3 m/s | 5.7 |
| 1991 | 13.6°C | 8.1°C | 2.6°C | 19.8°C | -2.0°C | 99 mm | 76% | 0.2 m/s | 4.7 |
| 1990 | 13.0°C | 7.9°C | 2.8°C | 21.9°C | -2.3°C | 143 mm | 78% | 0.2 m/s | 4.6 |
| 1989 | 14.1°C | 8.4°C | 2.7°C | 20.3°C | -1.2°C | 78 mm | 70% | 0.3 m/s | 4.7 |
| 1988 | 15.5°C | 9.5°C | 3.6°C | 25.1°C | -4.3°C | 54 mm | 69% | 0.2 m/s | 5.3 |
| 1987 | 16.5°C | 10.2°C | 3.9°C | 25.0°C | -1.8°C | 67 mm | 66% | 0.3 m/s | 5.2 |
| 1986 | 15.1°C | 9.2°C | 3.4°C | 29.6°C | -4.9°C | 60 mm | 71% | 0.3 m/s | 5.1 |
| 1985 | 16.2°C | 10.2°C | 4.1°C | 23.9°C | -4.7°C | 43 mm | 67% | 0.3 m/s | 5.5 |
| 1984 ❄️ | 11.0°C | 5.8°C | 0.6°C | 22.8°C | -2.1°C | 86 mm | 77% | 0.2 m/s | 4.7 |
| 1983 | 16.3°C | 10.1°C | 3.9°C | 30.2°C | -2.2°C | 37 mm | 68% | 0.3 m/s | — |
| 1982 | 13.8°C | 7.7°C | 1.5°C | 22.2°C | -4.5°C | 41 mm | 69% | 0.3 m/s | — |
| 1981 | 13.6°C | 8.3°C | 3.0°C | 21.3°C | -2.9°C | 102 mm | 75% | 0.3 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 15.1°C with lows near 3.3°C (mean 9.2°C), based on 45 years of NASA POWER data.
May averages 71 mm of rainfall in Trail, about average for rainfall. The wettest on record was 154 mm in 1998.
The hottest May reached 30.2°C in 1983. The coldest dipped to -4.9°C in 1986.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.1°C. Daytime highs moved from 14.2°C to 15.3°C and overnight lows from 2.6°C to 3.7°C over the same span.
May is one of the warmer months of the year in Trail and about average for rainfall, so plan for around 15.1°C daytime highs and 3.3°C at night.
Not quite — May is the 8th coolest month in Trail, averaging 9.2°C.
For May in Trail, pack warm layers and a jacket for chilly mornings, with typical highs of 15.1°C and lows of 3.3°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 71% — moderately humid.
Average wind speed in May is 0.3 m/s. The windiest May on record averaged 0.3 m/s (1981).
The wettest May on record was 1998 with 154 mm. On average, May sees 71 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 Trail 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.
