May is one of the warmer months of the year in Grand Falls, with average highs near 12.2°C and lows around 1.3°C (mean 6.8°C). It is about average for rainfall, averaging 82 mm of rainfall and 82% relative humidity across the period.
May is one of the warmer months of the year in Grand Falls. Across 45 years of records, the warmest May in Grand Falls was 1989 — when the month averaged 10.2°C — while the coldest was 2018 at 4.2°C. Typical May days reach 12.2°C with nights near 1.3°C. The long-term trend is cooling, about 0.2°C per decade.
May is about average for rainfall in Grand Falls, averaging 82 mm of rainfall. The wettest May on record was 1981 with 155 mm, while the driest was 1986 at 31 mm.
Relative humidity in Grand Falls during May averages 82%. The most humid May was 2010 at 87%, and the least humid was 1989 at 75%.
May receives about 4.7 kWh/m²/day of solar energy in Grand Falls. The sunniest May was 1999 at 5.5 kWh/m²/day, and the cloudiest was 1993 at 3.2.
Average wind speed in Grand Falls during May is 0.1 m/s. The windiest Mays were 2023, 2024 and 2025, among others at 0.1 m/s, while the calmest were 2023, 2024 and 2025, among others at 0.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 7.9°C | 6.4°C | 6.6°C | 6.6°C | 6.4°C | -1.5°C |
| Avg High | 13.7°C | 11.7°C | 12.1°C | 12.0°C | 11.8°C | -1.9°C |
| Avg Low | 2.2°C | 1.0°C | 1.1°C | 1.2°C | 1.0°C | -1.2°C |
| Avg Rain | 75 mm | 87 mm | 86 mm | 85 mm | 76 mm | +1 mm |
May temperatures in Grand Falls have fallen by about 0.9°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -8.2°C (2018) to a record high of 28.1°C (1999).
Rainfall in May is about average for rainfall, averaging 82 mm, with a wettest year of 155 mm.
A good time to visit Grand Falls
May is a good time to visit Grand Falls, with days averaging 12.2°C and nights around 1.3°C (mean 6.8°C, warmer than Grand 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 | 12.0°C | 6.5°C | 1.0°C | 22.2°C | -4.2°C | 51 mm | 82% | 0.1 m/s | 5 |
| 2024 | 12.1°C | 6.9°C | 1.7°C | 21.6°C | -2.7°C | 97 mm | 85% | 0.1 m/s | 4.4 |
| 2023 | 10.7°C | 5.4°C | 0.2°C | 23.5°C | -4.3°C | 74 mm | 82% | 0.1 m/s | 4.8 |
| 2022 | 12.1°C | 6.3°C | 0.4°C | 19.0°C | -4.3°C | 83 mm | 81% | 0.1 m/s | 5.1 |
| 2021 | 11.9°C | 6.8°C | 1.7°C | 22.6°C | -1.9°C | 75 mm | 81% | 0.1 m/s | 4.7 |
| 2020 | 11.7°C | 6.3°C | 0.8°C | 25.5°C | -2.9°C | 73 mm | 81% | 0.1 m/s | 4.4 |
| 2019 | 9.8°C | 5.2°C | 0.6°C | 20.0°C | -3.3°C | 52 mm | 84% | 0.1 m/s | 4.5 |
| 2018 ❄️ | 9.8°C | 4.2°C | -1.4°C | 18.9°C | -8.2°C | 102 mm | 78% | 0.1 m/s | 5.1 |
| 2017 | 11.9°C | 5.9°C | -0.1°C | 19.0°C | -4.7°C | 84 mm | 83% | 0.1 m/s | 5 |
| 2016 | 13.0°C | 7.3°C | 1.7°C | 22.4°C | -2.1°C | 98 mm | 84% | 0.1 m/s | 4.4 |
| 2015 | 13.6°C | 7.6°C | 1.6°C | 24.4°C | -3.7°C | 74 mm | 81% | 0.1 m/s | 5.1 |
| 2014 | 11.1°C | 5.8°C | 0.5°C | 25.0°C | -4.3°C | 79 mm | 85% | 0.1 m/s | 4.6 |
| 2013 | 13.8°C | 8.2°C | 2.7°C | 23.1°C | -4.1°C | 88 mm | 83% | 0.1 m/s | 4.7 |
| 2012 | 14.1°C | 8.8°C | 3.5°C | 25.8°C | -4.2°C | 56 mm | 82% | 0.1 m/s | 4.9 |
| 2011 | 12.2°C | 6.9°C | 1.6°C | 24.0°C | -3.5°C | 87 mm | 85% | 0.1 m/s | 4.3 |
| 2010 | 10.2°C | 5.8°C | 1.4°C | 20.8°C | -1.5°C | 130 mm | 87% | 0.1 m/s | 4.1 |
| 2009 | 12.8°C | 6.9°C | 1.0°C | 20.9°C | -4.6°C | 103 mm | 79% | 0.1 m/s | 5.1 |
| 2008 | 12.0°C | 6.9°C | 1.8°C | 20.0°C | -2.3°C | 75 mm | 83% | 0.1 m/s | 4.3 |
| 2007 | 10.9°C | 5.2°C | -0.5°C | 19.3°C | -4.0°C | 84 mm | 83% | 0.1 m/s | 4.4 |
| 2006 | 14.6°C | 8.8°C | 2.9°C | 23.8°C | -3.6°C | 66 mm | 82% | 0.1 m/s | 5 |
| 2005 | 13.2°C | 7.8°C | 2.5°C | 22.2°C | -2.0°C | 71 mm | 83% | 0.1 m/s | 4.6 |
| 2004 | 11.8°C | 6.2°C | 0.7°C | 19.1°C | -2.3°C | 81 mm | 77% | 0.1 m/s | 5.4 |
| 2003 | 11.6°C | 6.0°C | 0.5°C | 21.0°C | -4.2°C | 119 mm | 82% | 0.1 m/s | 4.9 |
| 2002 | 11.7°C | 6.3°C | 0.9°C | 20.7°C | -4.4°C | 81 mm | 81% | 0.1 m/s | 4.8 |
| 2001 | 11.4°C | 6.2°C | 1.0°C | 22.6°C | -4.4°C | 69 mm | 83% | 0.1 m/s | 4.5 |
| 2000 | 10.8°C | 5.5°C | 0.2°C | 19.2°C | -4.4°C | 115 mm | 82% | 0.1 m/s | 4.7 |
| 1999 | 16.4°C | 10.0°C | 3.6°C | 28.1°C | -3.3°C | 76 mm | 81% | 0.1 m/s | 5.5 |
| 1998 | 14.2°C | 8.7°C | 3.2°C | 22.1°C | -3.7°C | 81 mm | 83% | 0.1 m/s | 4.5 |
| 1997 | 10.6°C | 5.8°C | 1.0°C | 15.3°C | -3.7°C | 94 mm | 86% | 0.1 m/s | 4.4 |
| 1996 | 10.4°C | 5.4°C | 0.4°C | 17.5°C | -4.3°C | 79 mm | 82% | 0.1 m/s | 3.9 |
| 1995 | 10.0°C | 5.3°C | 0.6°C | 19.1°C | -3.3°C | 36 mm | 83% | 0.1 m/s | 5.1 |
| 1994 | 11.1°C | 5.7°C | 0.2°C | 18.9°C | -4.6°C | 126 mm | 84% | 0.1 m/s | 4.5 |
| 1993 | 11.1°C | 6.3°C | 1.5°C | 21.6°C | -6.6°C | 112 mm | 86% | 0.1 m/s | 3.2 |
| 1992 | 11.5°C | 5.7°C | -0.1°C | 23.6°C | -4.0°C | 75 mm | 81% | 0.1 m/s | 4.5 |
| 1991 | 11.1°C | 5.4°C | -0.3°C | 18.9°C | -4.6°C | 92 mm | 80% | 0.1 m/s | 4.3 |
| 1990 | 10.6°C | 5.2°C | -0.3°C | 21.9°C | -4.4°C | 94 mm | 81% | 0.1 m/s | 4.3 |
| 1989 🔥 | 17.3°C | 10.2°C | 3.1°C | 23.0°C | -3.6°C | 34 mm | 75% | 0.1 m/s | 5.2 |
| 1988 | 15.6°C | 9.7°C | 3.8°C | 24.6°C | -2.8°C | 64 mm | 81% | 0.1 m/s | 4.5 |
| 1987 | 14.2°C | 7.7°C | 1.1°C | 20.9°C | -3.4°C | 45 mm | 77% | 0.1 m/s | 4.9 |
| 1986 | 13.8°C | 7.3°C | 0.9°C | 24.6°C | -4.1°C | 31 mm | 79% | 0.1 m/s | 4.9 |
| 1985 | 11.2°C | 5.5°C | -0.1°C | 22.2°C | -6.5°C | 75 mm | 82% | 0.1 m/s | 4.9 |
| 1984 | 13.9°C | 8.5°C | 3.2°C | 23.1°C | -2.3°C | 91 mm | 85% | 0.1 m/s | 4.5 |
| 1983 | 11.7°C | 6.7°C | 1.8°C | 18.5°C | -3.1°C | 80 mm | 85% | 0.1 m/s | — |
| 1982 | 11.8°C | 6.9°C | 1.9°C | 20.1°C | -2.4°C | 98 mm | 85% | 0.1 m/s | — |
| 1981 🌧️ | 13.9°C | 8.8°C | 3.8°C | 22.9°C | -1.8°C | 155 mm | 86% | 0.1 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 12.2°C with lows near 1.3°C (mean 6.8°C), based on 45 years of NASA POWER data.
May averages 82 mm of rainfall in Grand Falls, about average for rainfall. The wettest on record was 155 mm in 1981.
The hottest May reached 28.1°C in 1999. The coldest dipped to -8.2°C in 2018.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have fallen by about 0.9°C. Daytime highs moved from 12.5°C to 11.8°C and overnight lows from 2.1°C to 1°C over the same span.
May is one of the warmer months of the year in Grand Falls and about average for rainfall, so plan for around 12.2°C daytime highs and 1.3°C at night.
Not quite — May is the 8th coolest month in Grand Falls, averaging 6.8°C.
For May in Grand Falls, pack warm layers and a jacket for chilly mornings, with typical highs of 12.2°C and lows of 1.3°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 82% — quite humid.
Average wind speed in May is 0.1 m/s. The windiest May on record averaged 0.1 m/s (1981).
The wettest May on record was 1981 with 155 mm. On average, May sees 82 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 Grand 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.
