May is one of the warmer months of the year in Niagara Falls, with average highs near 17°C and lows around 8°C (mean 12.5°C). It is about average for rainfall, averaging 72 mm of rainfall and 76% relative humidity across the period.
May is one of the warmer months of the year in Niagara Falls. Across 45 years of records, the warmest May in Niagara Falls was 1998 — when the month averaged 16.2°C — while the coldest were 1984 and 2002 at 9.1°C. Typical May days reach 17°C with nights near 8°C. The long-term trend is warming, about 0.5°C per decade.
May is about average for rainfall in Niagara Falls, averaging 72 mm of rainfall. The wettest May on record was 2004 with 155 mm, while the driest was 2021 at 27 mm.
Relative humidity in Niagara Falls during May averages 76%. The most humid May was 2011 at 87%, and the least humid was 2021 at 66%.
May receives about 5.5 kWh/m²/day of solar energy in Niagara Falls. The sunniest May was 2023 at 6.3 kWh/m²/day, and the cloudiest was 1984 at 4.4.
Average wind speed in Niagara Falls during May is 2.8 m/s. The windiest May was 1997 at 3.7 m/s, while the calmest was 1982 at 2.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 12.0°C | 12.0°C | 11.8°C | 13.6°C | 13.4°C | +1.4°C |
| Avg High | 16.4°C | 16.7°C | 16.2°C | 17.9°C | 17.9°C | +1.5°C |
| Avg Low | 7.5°C | 7.3°C | 7.5°C | 9.2°C | 8.9°C | +1.4°C |
| Avg Rain | 72 mm | 60 mm | 86 mm | 83 mm | 48 mm | -24 mm |
May temperatures in Niagara Falls have risen by about 2.4°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -1°C (2020) to a record high of 28.6°C (2016).
Rainfall in May is about average for rainfall, averaging 72 mm, with a wettest year of 155 mm.
A good time to visit Niagara Falls
May is a good time to visit Niagara Falls, with days averaging 17°C and nights around 8°C (mean 12.5°C, warmer than Niagara Falls'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 | 16.7°C | 12.7°C | 8.7°C | 24.0°C | 3.9°C | 68 mm | 77% | 3.2 m/s | 5 |
| 2024 | 20.2°C | 15.8°C | 11.3°C | 26.5°C | 6.8°C | 54 mm | 75% | 2.4 m/s | 5.7 |
| 2023 | 17.5°C | 12.8°C | 8.2°C | 28.2°C | 2.6°C | 30 mm | 68% | 2.5 m/s | 6.3 |
| 2022 | 18.8°C | 14.2°C | 9.6°C | 26.0°C | 2.6°C | 56 mm | 75% | 2.6 m/s | 5.7 |
| 2021 | 18.2°C | 13.4°C | 8.5°C | 28.3°C | 0.9°C | 27 mm | 66% | 2.7 m/s | 5.7 |
| 2020 | 15.7°C | 11.5°C | 7.3°C | 27.9°C | -1.0°C | 52 mm | 77% | 3 m/s | 5.4 |
| 2019 | 15.5°C | 11.1°C | 6.7°C | 22.8°C | 2.5°C | 88 mm | 83% | 2.6 m/s | 4.6 |
| 2018 | 19.4°C | 14.7°C | 10.0°C | 28.0°C | 3.4°C | 66 mm | 79% | 2.6 m/s | 6.1 |
| 2017 | 15.7°C | 12.1°C | 8.4°C | 22.6°C | 2.0°C | 136 mm | 81% | 3 m/s | 5 |
| 2016 | 17.7°C | 13.4°C | 9.0°C | 28.6°C | 2.9°C | 38 mm | 74% | 2.6 m/s | 6 |
| 2015 | 19.7°C | 14.7°C | 9.8°C | 26.3°C | 3.8°C | 65 mm | 73% | 2.8 m/s | 5.8 |
| 2014 | 16.5°C | 12.3°C | 8.2°C | 22.2°C | 1.0°C | 88 mm | 81% | 2.6 m/s | 5.4 |
| 2013 | 19.0°C | 14.2°C | 9.5°C | 25.8°C | 2.1°C | 81 mm | 75% | 2.9 m/s | 6.1 |
| 2012 | 20.9°C | 16.1°C | 11.3°C | 27.9°C | 5.3°C | 44 mm | 72% | 2.3 m/s | 6 |
| 2011 | 16.0°C | 12.4°C | 8.7°C | 24.4°C | 3.0°C | 146 mm | 87% | 2.6 m/s | 4.5 |
| 2010 | 19.0°C | 14.6°C | 10.1°C | 28.3°C | 1.0°C | 73 mm | 75% | 2.8 m/s | 5.7 |
| 2009 | 16.8°C | 12.2°C | 7.6°C | 21.5°C | 1.3°C | 67 mm | 74% | 3 m/s | 6.1 |
| 2008 | 15.0°C | 10.7°C | 6.4°C | 20.7°C | 0.9°C | 64 mm | 76% | 2.9 m/s | 5.3 |
| 2007 | 17.9°C | 13.2°C | 8.4°C | 26.8°C | 2.5°C | 33 mm | 71% | 2.4 m/s | 6.2 |
| 2006 | 18.1°C | 13.7°C | 9.3°C | 27.9°C | 3.6°C | 57 mm | 75% | 2.7 m/s | 5.5 |
| 2005 | 15.2°C | 11.1°C | 7.0°C | 22.1°C | 1.4°C | 28 mm | 74% | 2.6 m/s | 5.9 |
| 2004 🌧️ | 16.9°C | 12.6°C | 8.3°C | 25.4°C | -0.5°C | 155 mm | 84% | 2.7 m/s | 4.9 |
| 2003 | 14.4°C | 10.4°C | 6.3°C | 20.1°C | 1.4°C | 132 mm | 83% | 2.7 m/s | 4.8 |
| 2002 | 13.4°C | 9.1°C | 4.7°C | 21.5°C | -0.2°C | 114 mm | 80% | 3.2 m/s | 5.1 |
| 2001 | 17.2°C | 12.5°C | 7.9°C | 21.5°C | 2.1°C | 101 mm | 75% | 2.7 m/s | 5.6 |
| 2000 | 16.7°C | 12.7°C | 8.7°C | 22.1°C | 4.7°C | 114 mm | 83% | 3.2 m/s | 4.9 |
| 1999 | 18.9°C | 14.0°C | 9.1°C | 26.4°C | 4.4°C | 63 mm | 71% | 2.8 m/s | 6.1 |
| 1998 🔥 | 20.7°C | 16.2°C | 11.7°C | 26.3°C | 8.1°C | 54 mm | 74% | 2.5 m/s | 5.8 |
| 1997 | 13.5°C | 9.2°C | 5.0°C | 20.0°C | 0.1°C | 68 mm | 74% | 3.7 m/s | 4.9 |
| 1996 | 14.5°C | 10.0°C | 5.6°C | 21.2°C | -0.5°C | 70 mm | 76% | 2.9 m/s | 5.6 |
| 1995 | 16.7°C | 11.8°C | 6.9°C | 21.7°C | 1.2°C | 38 mm | 70% | 2.9 m/s | 5.4 |
| 1994 | 15.4°C | 10.4°C | 5.3°C | 25.4°C | 0.3°C | 57 mm | 72% | 2.9 m/s | 5.3 |
| 1993 | 16.3°C | 11.5°C | 6.7°C | 24.5°C | 3.2°C | 38 mm | 71% | 2.9 m/s | 5.1 |
| 1992 | 16.8°C | 11.7°C | 6.5°C | 23.9°C | 2.0°C | 46 mm | 70% | 2.4 m/s | 6.1 |
| 1991 | 19.4°C | 14.7°C | 10.1°C | 26.7°C | 0.9°C | 54 mm | 78% | 2.8 m/s | 5.5 |
| 1990 | 14.8°C | 10.4°C | 6.0°C | 20.7°C | 1.5°C | 116 mm | 76% | 3.1 m/s | 5 |
| 1989 | 15.4°C | 11.2°C | 7.1°C | 23.6°C | 1.1°C | 95 mm | 78% | 2.9 m/s | 4.9 |
| 1988 | 17.6°C | 12.6°C | 7.6°C | 28.1°C | 2.3°C | 48 mm | 71% | 2.7 m/s | 5.8 |
| 1987 | 18.7°C | 13.8°C | 8.9°C | 27.7°C | 1.5°C | 31 mm | 71% | 3 m/s | 5.9 |
| 1986 | 17.2°C | 13.0°C | 8.7°C | 23.7°C | -0.8°C | 75 mm | 78% | 3 m/s | 5.4 |
| 1985 | 16.7°C | 12.4°C | 8.1°C | 21.7°C | 2.4°C | 64 mm | 76% | 3.1 m/s | 5.7 |
| 1984 ❄️ | 12.9°C | 9.1°C | 5.4°C | 20.6°C | 0.6°C | 103 mm | 82% | 3.4 m/s | 4.4 |
| 1983 | 14.5°C | 10.0°C | 5.6°C | 21.5°C | -0.4°C | 88 mm | 80% | 3.3 m/s | — |
| 1982 | 18.2°C | 13.7°C | 9.1°C | 23.4°C | 3.6°C | 78 mm | 78% | 2.1 m/s | — |
| 1981 | 16.7°C | 12.0°C | 7.3°C | 24.1°C | 1.4°C | 66 mm | 72% | 2.4 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 17°C with lows near 8°C (mean 12.5°C), based on 45 years of NASA POWER data.
May averages 72 mm of rainfall in Niagara Falls, about average for rainfall. The wettest on record was 155 mm in 2004.
The hottest May reached 28.6°C in 2016. The coldest dipped to -1°C in 2020.
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 15.8°C to 18.3°C and overnight lows from 7.1°C to 9.3°C over the same span.
May is one of the warmer months of the year in Niagara Falls and about average for rainfall, so plan for around 17°C daytime highs and 8°C at night.
Not quite — May is the 8th coolest month in Niagara Falls, averaging 12.5°C.
For May in Niagara Falls, pack light layers you can adjust through the day, with typical highs of 17°C and lows of 8°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 76% — quite humid.
Average wind speed in May is 2.8 m/s. The windiest May on record averaged 3.7 m/s (1997).
The wettest May on record was 2004 with 155 mm. On average, May sees 72 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 Niagara Falls 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.
