May is one of the warmer months of the year in Amherst, with average highs near 14°C and lows around 4.4°C (mean 9.2°C). It is about average for rainfall, averaging 79 mm of rainfall and 81% relative humidity across the period.
May is one of the warmer months of the year in Amherst. Across 45 years of records, the warmest May in Amherst was 1989 — when the month averaged 11.7°C — while the coldest were 1990 and 2019 at 7.1°C. Typical May days reach 14°C with nights near 4.4°C. The long-term trend is warming, about 0.2°C per decade.
May is about average for rainfall in Amherst, averaging 79 mm of rainfall. The wettest May on record was 1990 with 190 mm, while the driest was 1992 at 26 mm.
Relative humidity in Amherst during May averages 81%. The most humid May was 2011 at 88%, and the least humid was 1987 at 74%.
May receives about 5.2 kWh/m²/day of solar energy in Amherst. The sunniest Mays were 1999 and 2018 at 6.2 kWh/m²/day, and the cloudiest was 2011 at 4.
Average wind speed in Amherst during May is 0.8 m/s. The windiest Mays were 2010, 2020 and 2023 at 1 m/s, while the calmest was 2006 at 0.6 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 9.3°C | 8.7°C | 8.9°C | 9.5°C | 9.7°C | +0.4°C |
| Avg High | 14.2°C | 13.7°C | 13.5°C | 14.2°C | 14.6°C | +0.4°C |
| Avg Low | 4.4°C | 3.8°C | 4.2°C | 4.9°C | 4.9°C | +0.5°C |
| Avg Rain | 80 mm | 77 mm | 92 mm | 73 mm | 66 mm | -14 mm |
May temperatures in Amherst have risen by about 1°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -3.1°C (1987) to a record high of 27.2°C (1992).
Rainfall in May is about average for rainfall, averaging 79 mm, with a wettest year of 190 mm.
A good time to visit Amherst
May is a good time to visit Amherst, with days averaging 14°C and nights around 4.4°C (mean 9.2°C, warmer than Amherst'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 | 14.8°C | 10.1°C | 5.4°C | 24.0°C | 0.5°C | 87 mm | 81% | 0.9 m/s | 4.6 |
| 2024 | 15.3°C | 10.6°C | 6.0°C | 22.2°C | 0.3°C | 53 mm | 82% | 0.8 m/s | 5.4 |
| 2023 | 14.0°C | 9.1°C | 4.2°C | 24.9°C | 0.8°C | 45 mm | 77% | 1 m/s | 5.7 |
| 2022 | 15.6°C | 10.3°C | 5.0°C | 23.7°C | -2.2°C | 62 mm | 77% | 0.8 m/s | 6.1 |
| 2021 | 14.3°C | 9.5°C | 4.7°C | 21.5°C | 0.7°C | 78 mm | 78% | 0.9 m/s | 5.3 |
| 2020 | 13.6°C | 8.7°C | 3.9°C | 21.7°C | -0.6°C | 69 mm | 78% | 1 m/s | 5.5 |
| 2019 | 11.5°C | 7.1°C | 2.8°C | 19.0°C | -2.0°C | 88 mm | 82% | 0.8 m/s | 4.6 |
| 2018 | 15.1°C | 9.5°C | 3.9°C | 23.0°C | -1.8°C | 76 mm | 77% | 0.8 m/s | 6.2 |
| 2017 | 13.9°C | 9.3°C | 4.8°C | 24.4°C | -0.1°C | 115 mm | 84% | 0.8 m/s | 4.8 |
| 2016 | 14.7°C | 9.9°C | 5.2°C | 23.0°C | -1.4°C | 64 mm | 82% | 0.8 m/s | 4.9 |
| 2015 | 15.2°C | 10.1°C | 5.1°C | 23.1°C | -2.1°C | 58 mm | 79% | 0.8 m/s | 5.4 |
| 2014 | 13.1°C | 8.4°C | 3.8°C | 19.8°C | -1.0°C | 50 mm | 82% | 0.8 m/s | 5.2 |
| 2013 | 15.0°C | 10.4°C | 5.9°C | 23.6°C | -1.2°C | 65 mm | 82% | 0.9 m/s | 5.2 |
| 2012 | 15.8°C | 11.0°C | 6.2°C | 21.1°C | 0.1°C | 62 mm | 81% | 0.7 m/s | 5.1 |
| 2011 | 13.3°C | 9.5°C | 5.8°C | 22.4°C | 1.2°C | 111 mm | 88% | 0.9 m/s | 4 |
| 2010 | 14.8°C | 10.2°C | 5.6°C | 24.5°C | 1.4°C | 42 mm | 80% | 1 m/s | 5.6 |
| 2009 | 14.8°C | 10.2°C | 5.6°C | 21.9°C | 2.3°C | 78 mm | 81% | 0.8 m/s | 4.9 |
| 2008 | 13.2°C | 8.9°C | 4.5°C | 19.4°C | 0.7°C | 90 mm | 83% | 0.9 m/s | 5.3 |
| 2007 | 13.0°C | 8.5°C | 3.9°C | 23.3°C | -1.4°C | 88 mm | 81% | 0.8 m/s | 5 |
| 2006 | 15.3°C | 10.3°C | 5.2°C | 21.8°C | 0.6°C | 68 mm | 82% | 0.6 m/s | 5 |
| 2005 | 11.3°C | 7.6°C | 3.9°C | 19.3°C | -0.9°C | 166 mm | 84% | 0.9 m/s | 4.3 |
| 2004 | 14.0°C | 8.8°C | 3.6°C | 20.7°C | -1.4°C | 42 mm | 78% | 0.8 m/s | 4.7 |
| 2003 | 12.6°C | 8.0°C | 3.3°C | 23.7°C | -2.1°C | 77 mm | 83% | 0.7 m/s | 4.8 |
| 2002 | 13.4°C | 8.6°C | 3.8°C | 20.8°C | -1.8°C | 76 mm | 77% | 0.8 m/s | 5.8 |
| 2001 | 14.8°C | 9.6°C | 4.5°C | 23.5°C | -1.4°C | 128 mm | 82% | 0.7 m/s | 5.5 |
| 2000 | 12.5°C | 8.0°C | 3.4°C | 18.6°C | -0.5°C | 109 mm | 80% | 0.8 m/s | 5 |
| 1999 | 17.1°C | 11.4°C | 5.8°C | 23.3°C | 0.2°C | 30 mm | 77% | 0.7 m/s | 6.2 |
| 1998 | 16.8°C | 11.5°C | 6.2°C | 21.5°C | 0.6°C | 61 mm | 80% | 0.7 m/s | 5.7 |
| 1997 | 12.0°C | 7.8°C | 3.5°C | 18.1°C | -0.4°C | 62 mm | 81% | 0.8 m/s | 4.9 |
| 1996 | 12.3°C | 7.7°C | 3.1°C | 19.4°C | -2.1°C | 96 mm | 79% | 0.7 m/s | 4.7 |
| 1995 | 13.0°C | 7.9°C | 2.9°C | 18.0°C | -0.5°C | 49 mm | 79% | 0.7 m/s | 5 |
| 1994 | 12.0°C | 7.8°C | 3.7°C | 20.3°C | 0.9°C | 103 mm | 82% | 0.8 m/s | 4.8 |
| 1993 | 13.5°C | 8.5°C | 3.5°C | 19.7°C | -3.1°C | 61 mm | 81% | 0.7 m/s | 4.5 |
| 1992 | 14.2°C | 8.2°C | 2.3°C | 27.2°C | -2.7°C | 26 mm | 76% | 0.7 m/s | 6 |
| 1991 | 14.6°C | 9.3°C | 4.0°C | 22.9°C | -2.7°C | 95 mm | 78% | 0.8 m/s | 5.4 |
| 1990 ❄️ 🌧️ | 11.3°C | 7.1°C | 2.9°C | 20.8°C | -0.2°C | 190 mm | 83% | 0.8 m/s | 4.6 |
| 1989 🔥 | 16.7°C | 11.7°C | 6.7°C | 21.9°C | 0.8°C | 67 mm | 84% | 0.7 m/s | 4.9 |
| 1988 | 14.4°C | 9.4°C | 4.4°C | 20.0°C | -0.4°C | 75 mm | 82% | 0.7 m/s | 4.9 |
| 1987 | 14.8°C | 9.2°C | 3.6°C | 22.0°C | -3.1°C | 43 mm | 74% | 0.7 m/s | 6 |
| 1986 | 14.1°C | 9.0°C | 4.0°C | 24.3°C | -2.0°C | 65 mm | 79% | 0.8 m/s | 5.8 |
| 1985 | 13.0°C | 8.1°C | 3.1°C | 20.6°C | -1.6°C | 117 mm | 80% | 0.7 m/s | 5.6 |
| 1984 | 13.2°C | 8.9°C | 4.7°C | 20.0°C | 0.5°C | 93 mm | 85% | 0.7 m/s | 4.4 |
| 1983 | 13.3°C | 8.9°C | 4.6°C | 19.1°C | -1.6°C | 123 mm | 84% | 0.7 m/s | — |
| 1982 | 13.0°C | 8.1°C | 3.2°C | 22.9°C | -1.3°C | 56 mm | 81% | 0.8 m/s | — |
| 1981 | 15.4°C | 10.5°C | 5.6°C | 21.4°C | -1.7°C | 83 mm | 83% | 0.8 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 14°C with lows near 4.4°C (mean 9.2°C), based on 45 years of NASA POWER data.
May averages 79 mm of rainfall in Amherst, about average for rainfall. The wettest on record was 190 mm in 1990.
The hottest May reached 27.2°C in 1992. The coldest dipped to -3.1°C in 1987.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1°C. Daytime highs moved from 13.6°C to 14.8°C and overnight lows from 4.2°C to 5.1°C over the same span.
May is one of the warmer months of the year in Amherst and about average for rainfall, so plan for around 14°C daytime highs and 4.4°C at night.
Not quite — May is the 7th coolest month in Amherst, averaging 9.2°C.
For May in Amherst, pack warm layers and a jacket for chilly mornings, with typical highs of 14°C and lows of 4.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 81% — quite humid.
Average wind speed in May is 0.8 m/s. The windiest May on record averaged 1 m/s (2010).
The wettest May on record was 1990 with 190 mm. On average, May sees 79 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 Amherst 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.
