May is one of the warmer months of the year in Niagara Falls, with average highs near 18.1°C and lows around 7.8°C (mean 13°C). It is about average for rainfall, averaging 80 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 2012 — when the month averaged 16.4°C — while the coldest was 1997 at 9.2°C. Typical May days reach 18.1°C with nights near 7.8°C. The long-term trend is warming, about 0.4°C per decade.
May is about average for rainfall in Niagara Falls, averaging 80 mm of rainfall. The wettest May on record was 2011 with 158 mm, while the driest was 2005 at 27 mm.
Relative humidity in Niagara Falls during May averages 76%. The most humid May was 2011 at 86%, and the least humid was 2021 at 68%.
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 1.3 m/s. The windiest May was 1997 at 1.6 m/s, while the calmest was 1982 at 1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 12.6°C | 12.4°C | 12.4°C | 14.1°C | 13.6°C | +1°C |
| Avg High | 17.7°C | 17.7°C | 17.6°C | 19.3°C | 18.6°C | +0.9°C |
| Avg Low | 7.4°C | 7.1°C | 7.3°C | 9.0°C | 8.4°C | +1°C |
| Avg Rain | 81 mm | 75 mm | 88 mm | 88 mm | 64 mm | -18 mm |
May temperatures in Niagara Falls have risen by about 1.8°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -1.6°C (2020) to a record high of 31°C (2006).
Rainfall in May is about average for rainfall, averaging 80 mm, with a wettest year of 158 mm.
A good time to visit Niagara Falls
May is a good time to visit Niagara Falls, with days averaging 18.1°C and nights around 7.8°C (mean 13°C, warmer than Niagara Falls'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 | 17.3°C | 12.7°C | 8.1°C | 26.0°C | 2.0°C | 108 mm | 80% | 1.4 m/s | 5 |
| 2024 | 21.0°C | 16.1°C | 11.1°C | 27.4°C | 6.1°C | 65 mm | 76% | 1.1 m/s | 5.7 |
| 2023 | 18.0°C | 12.7°C | 7.3°C | 29.2°C | 1.8°C | 35 mm | 70% | 1.1 m/s | 6.3 |
| 2022 | 20.0°C | 14.6°C | 9.2°C | 27.6°C | 1.0°C | 67 mm | 76% | 1.2 m/s | 5.7 |
| 2021 | 18.8°C | 13.4°C | 7.9°C | 29.9°C | 0.5°C | 41 mm | 68% | 1.2 m/s | 5.7 |
| 2020 | 16.6°C | 11.8°C | 6.9°C | 29.6°C | -1.6°C | 66 mm | 77% | 1.3 m/s | 5.4 |
| 2019 | 16.8°C | 11.7°C | 6.7°C | 25.1°C | 2.1°C | 91 mm | 83% | 1.2 m/s | 4.6 |
| 2018 | 21.0°C | 15.5°C | 10.1°C | 29.1°C | 2.9°C | 67 mm | 79% | 1.2 m/s | 6.1 |
| 2017 | 16.5°C | 12.3°C | 8.1°C | 24.9°C | 1.3°C | 146 mm | 82% | 1.4 m/s | 5 |
| 2016 | 18.8°C | 13.5°C | 8.3°C | 30.9°C | 2.2°C | 44 mm | 73% | 1.2 m/s | 6 |
| 2015 | 21.5°C | 15.7°C | 9.9°C | 29.1°C | 2.6°C | 83 mm | 71% | 1.3 m/s | 5.8 |
| 2014 | 17.7°C | 13.0°C | 8.2°C | 25.1°C | 1.4°C | 93 mm | 80% | 1.2 m/s | 5.4 |
| 2013 | 20.4°C | 14.9°C | 9.4°C | 27.9°C | 1.5°C | 80 mm | 74% | 1.3 m/s | 6.1 |
| 2012 🔥 | 22.0°C | 16.4°C | 10.8°C | 29.8°C | 4.4°C | 43 mm | 72% | 1.1 m/s | 6 |
| 2011 🌧️ | 17.8°C | 13.4°C | 9.1°C | 27.1°C | 3.2°C | 158 mm | 86% | 1.2 m/s | 4.5 |
| 2010 | 20.1°C | 14.8°C | 9.5°C | 29.6°C | 0.1°C | 70 mm | 74% | 1.3 m/s | 5.7 |
| 2009 | 18.1°C | 12.7°C | 7.2°C | 23.7°C | 0.4°C | 71 mm | 73% | 1.4 m/s | 6.1 |
| 2008 | 16.0°C | 10.9°C | 5.8°C | 23.2°C | -1.0°C | 63 mm | 75% | 1.3 m/s | 5.3 |
| 2007 | 19.0°C | 13.4°C | 7.8°C | 28.1°C | 1.2°C | 31 mm | 71% | 1.1 m/s | 6.2 |
| 2006 | 19.1°C | 13.9°C | 8.8°C | 31.0°C | 2.1°C | 60 mm | 74% | 1.3 m/s | 5.5 |
| 2005 | 16.1°C | 11.2°C | 6.3°C | 23.6°C | -0.3°C | 27 mm | 74% | 1.2 m/s | 5.9 |
| 2004 | 19.0°C | 13.8°C | 8.6°C | 27.4°C | 0.2°C | 155 mm | 83% | 1.2 m/s | 4.9 |
| 2003 | 16.0°C | 11.2°C | 6.5°C | 22.9°C | 1.4°C | 131 mm | 82% | 1.2 m/s | 4.8 |
| 2002 | 14.9°C | 10.0°C | 5.0°C | 23.7°C | -0.2°C | 129 mm | 78% | 1.5 m/s | 5.1 |
| 2001 | 19.3°C | 13.7°C | 8.2°C | 24.4°C | 2.5°C | 95 mm | 72% | 1.2 m/s | 5.6 |
| 2000 | 18.2°C | 13.4°C | 8.7°C | 24.3°C | 4.1°C | 117 mm | 81% | 1.4 m/s | 4.9 |
| 1999 | 20.4°C | 14.6°C | 8.8°C | 28.8°C | 3.0°C | 66 mm | 69% | 1.3 m/s | 6.1 |
| 1998 | 21.0°C | 16.0°C | 11.1°C | 27.3°C | 6.2°C | 74 mm | 78% | 1.1 m/s | 5.9 |
| 1997 ❄️ | 14.1°C | 9.2°C | 4.3°C | 20.9°C | -1.1°C | 75 mm | 75% | 1.6 m/s | 4.9 |
| 1996 | 15.6°C | 10.7°C | 5.7°C | 23.9°C | 0.0°C | 99 mm | 77% | 1.2 m/s | 5.6 |
| 1995 | 17.6°C | 12.1°C | 6.6°C | 23.4°C | -0.4°C | 53 mm | 71% | 1.3 m/s | 5.4 |
| 1994 | 16.3°C | 10.7°C | 5.0°C | 26.1°C | -0.5°C | 81 mm | 75% | 1.3 m/s | 5.3 |
| 1993 | 17.6°C | 12.2°C | 6.8°C | 26.8°C | 2.1°C | 37 mm | 72% | 1.3 m/s | 5.1 |
| 1992 | 17.8°C | 12.0°C | 6.3°C | 25.0°C | 0.5°C | 68 mm | 74% | 1.1 m/s | 6.1 |
| 1991 | 20.6°C | 15.3°C | 10.1°C | 27.7°C | 0.5°C | 61 mm | 79% | 1.3 m/s | 5.5 |
| 1990 | 15.7°C | 10.8°C | 5.9°C | 22.2°C | 1.1°C | 137 mm | 78% | 1.4 m/s | 5.1 |
| 1989 | 16.3°C | 11.8°C | 7.2°C | 25.3°C | 0.5°C | 136 mm | 80% | 1.3 m/s | 4.9 |
| 1988 | 18.9°C | 13.2°C | 7.4°C | 27.9°C | 1.2°C | 58 mm | 72% | 1.2 m/s | 5.8 |
| 1987 | 19.8°C | 14.2°C | 8.5°C | 29.4°C | 0.8°C | 32 mm | 71% | 1.4 m/s | 5.9 |
| 1986 | 18.5°C | 13.6°C | 8.7°C | 25.2°C | -1.0°C | 77 mm | 77% | 1.4 m/s | 5.4 |
| 1985 | 18.4°C | 13.2°C | 8.1°C | 25.2°C | 1.7°C | 69 mm | 72% | 1.4 m/s | 5.7 |
| 1984 | 14.0°C | 9.7°C | 5.5°C | 23.4°C | 0.5°C | 137 mm | 81% | 1.5 m/s | 4.4 |
| 1983 | 15.8°C | 10.7°C | 5.5°C | 24.7°C | -0.9°C | 82 mm | 78% | 1.5 m/s | — |
| 1982 | 19.9°C | 14.5°C | 9.1°C | 25.6°C | 2.8°C | 72 mm | 76% | 1 m/s | — |
| 1981 | 17.8°C | 12.4°C | 7.0°C | 24.8°C | -0.3°C | 71 mm | 72% | 1.1 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 18.1°C with lows near 7.8°C (mean 13°C), based on 45 years of NASA POWER data.
May averages 80 mm of rainfall in Niagara Falls, about average for rainfall. The wettest on record was 158 mm in 2011.
The hottest May reached 31°C in 2006. The coldest dipped to -1.6°C in 2020.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.8°C. Daytime highs moved from 17.2°C to 19°C and overnight lows from 7°C to 8.7°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 18.1°C daytime highs and 7.8°C at night.
Not quite — May is the 8th coolest month in Niagara Falls, averaging 13°C.
For May in Niagara Falls, pack warm layers and a jacket for chilly mornings, with typical highs of 18.1°C and lows of 7.8°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 76% — quite humid.
Average wind speed in May is 1.3 m/s. The windiest May on record averaged 1.6 m/s (1997).
The wettest May on record was 2011 with 158 mm. On average, May sees 80 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.
