May is one of the warmer months of the year in Middletown, with average highs near 19.8°C and lows around 8.1°C (mean 14°C). It is a relatively wet time of year, averaging 111 mm of rainfall and 79% relative humidity across the period.
May is one of the warmer months of the year in Middletown. Across 45 years of records, the warmest May in Middletown was 2015 — when the month averaged 16.8°C — while the coldest was 1997 at 11°C. Typical May days reach 19.8°C with nights near 8.1°C. The long-term trend is warming, about 0.4°C per decade.
May is a relatively wet time of year in Middletown, averaging 111 mm of rainfall. The wettest May on record was 1989 with 271 mm, while the driest was 2023 at 26 mm.
Relative humidity in Middletown during May averages 79%. The most humid May was 2011 at 84%, and the least humid was 2015 at 73%.
May receives about 5.3 kWh/m²/day of solar energy in Middletown. The sunniest May was 2007 at 6.6 kWh/m²/day, and the cloudiest was 1984 at 4.
Average wind speed in Middletown 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 | 13.5°C | 13.3°C | 13.6°C | 15.0°C | 14.2°C | +0.7°C |
| Avg High | 19.5°C | 19.3°C | 19.5°C | 20.6°C | 20.0°C | +0.5°C |
| Avg Low | 7.5°C | 7.3°C | 7.8°C | 9.4°C | 8.5°C | +1°C |
| Avg Rain | 141 mm | 101 mm | 96 mm | 111 mm | 110 mm | -31 mm |
May temperatures in Middletown have risen by about 1.3°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -2.1°C (2020) to a record high of 31.4°C (1991).
Rainfall in May is a relatively wet time of year, averaging 111 mm, with a wettest year of 271 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.3°C per decade while lows rose 0.5°C per decade, narrowing the gap between day and night.
A good time to visit Middletown
May is a good time to visit Middletown, with days averaging 19.8°C and nights around 8.1°C (mean 14°C, warmer than Middletown'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 | 19.4°C | 14.3°C | 9.3°C | 26.3°C | 3.5°C | 225 mm | 83% | 0.1 m/s | 4.4 |
| 2024 | 21.5°C | 16.2°C | 10.8°C | 27.9°C | 4.4°C | 111 mm | 82% | 0.1 m/s | 5.3 |
| 2023 | 20.0°C | 13.4°C | 6.8°C | 26.3°C | -0.8°C | 26 mm | 73% | 0.1 m/s | 6.5 |
| 2022 | 21.2°C | 15.2°C | 9.2°C | 29.8°C | 0.9°C | 96 mm | 80% | 0.1 m/s | 5.3 |
| 2021 | 19.5°C | 13.8°C | 8.0°C | 29.6°C | 0.9°C | 128 mm | 77% | 0.1 m/s | 5.3 |
| 2020 | 18.2°C | 12.4°C | 6.6°C | 26.3°C | -2.1°C | 75 mm | 77% | 0.1 m/s | 6 |
| 2019 | 19.5°C | 14.2°C | 9.0°C | 26.9°C | 3.2°C | 169 mm | 83% | 0.1 m/s | 4.7 |
| 2018 | 21.8°C | 16.3°C | 10.8°C | 30.5°C | 0.8°C | 105 mm | 82% | 0.1 m/s | 5 |
| 2017 | 18.2°C | 13.1°C | 7.9°C | 29.2°C | 0.6°C | 129 mm | 80% | 0.1 m/s | 4.6 |
| 2016 | 19.3°C | 14.0°C | 8.6°C | 30.2°C | 1.2°C | 86 mm | 79% | 0.1 m/s | 5.1 |
| 2015 🔥 | 23.5°C | 16.8°C | 10.2°C | 29.0°C | 1.9°C | 56 mm | 73% | 0.1 m/s | 5.9 |
| 2014 | 20.0°C | 14.3°C | 8.5°C | 26.6°C | 1.9°C | 94 mm | 80% | 0.1 m/s | 5.3 |
| 2013 | 19.9°C | 14.1°C | 8.4°C | 29.1°C | -1.0°C | 122 mm | 79% | 0.1 m/s | 5.5 |
| 2012 | 21.9°C | 16.6°C | 11.2°C | 29.1°C | 3.2°C | 131 mm | 82% | 0.1 m/s | 4.9 |
| 2011 | 20.7°C | 15.5°C | 10.3°C | 29.3°C | 2.2°C | 146 mm | 84% | 0.1 m/s | 4.9 |
| 2010 | 21.4°C | 15.3°C | 9.2°C | 30.5°C | -1.1°C | 69 mm | 78% | 0.1 m/s | 5.7 |
| 2009 | 20.1°C | 14.2°C | 8.3°C | 27.0°C | 0.3°C | 120 mm | 79% | 0.1 m/s | 4.9 |
| 2008 | 17.8°C | 12.0°C | 6.3°C | 26.3°C | 0.5°C | 84 mm | 78% | 0.1 m/s | 5.3 |
| 2007 | 21.7°C | 14.8°C | 8.0°C | 31.2°C | 2.3°C | 37 mm | 76% | 0.1 m/s | 6.6 |
| 2006 | 19.7°C | 14.0°C | 8.4°C | 29.1°C | 0.9°C | 109 mm | 79% | 0.1 m/s | 5.2 |
| 2005 | 17.4°C | 11.6°C | 5.8°C | 25.7°C | 0.0°C | 40 mm | 78% | 0.1 m/s | 5.5 |
| 2004 | 21.9°C | 16.1°C | 10.2°C | 27.7°C | 0.8°C | 114 mm | 81% | 0.1 m/s | 5.4 |
| 2003 | 17.6°C | 12.6°C | 7.6°C | 23.4°C | 2.1°C | 125 mm | 83% | 0.1 m/s | 4.2 |
| 2002 | 18.7°C | 12.5°C | 6.4°C | 25.9°C | -1.4°C | 139 mm | 74% | 0.1 m/s | 5.5 |
| 2001 | 20.4°C | 14.5°C | 8.6°C | 29.4°C | 3.0°C | 80 mm | 75% | 0.1 m/s | 5.4 |
| 2000 | 19.7°C | 14.1°C | 8.4°C | 28.7°C | 0.7°C | 118 mm | 81% | 0.1 m/s | 5.1 |
| 1999 | 20.8°C | 14.3°C | 7.9°C | 29.7°C | 1.9°C | 89 mm | 74% | 0.1 m/s | 5.6 |
| 1998 | 21.2°C | 15.7°C | 10.2°C | 27.9°C | 2.2°C | 179 mm | 82% | 0.1 m/s | 5.6 |
| 1997 ❄️ | 17.0°C | 11.0°C | 5.1°C | 25.1°C | -0.9°C | 85 mm | 77% | 0.1 m/s | 5.5 |
| 1996 | 17.8°C | 11.9°C | 5.9°C | 28.7°C | -1.5°C | 79 mm | 80% | 0.1 m/s | 5 |
| 1995 | 18.0°C | 12.5°C | 6.9°C | 25.8°C | 0.7°C | 60 mm | 78% | 0.1 m/s | 4.7 |
| 1994 | 18.6°C | 12.5°C | 6.3°C | 27.2°C | 0.7°C | 87 mm | 78% | 0.1 m/s | 5.6 |
| 1993 | 20.2°C | 14.0°C | 7.8°C | 26.7°C | 3.4°C | 42 mm | 78% | 0.1 m/s | 5.6 |
| 1992 | 18.7°C | 12.5°C | 6.3°C | 27.4°C | -0.2°C | 114 mm | 78% | 0.1 m/s | 5.4 |
| 1991 | 22.8°C | 16.6°C | 10.5°C | 31.4°C | 3.3°C | 83 mm | 80% | 0.1 m/s | 6 |
| 1990 | 17.5°C | 11.8°C | 6.1°C | 23.0°C | 0.2°C | 189 mm | 80% | 0.1 m/s | 4.8 |
| 1989 🌧️ | 18.8°C | 13.3°C | 7.8°C | 27.2°C | 1.6°C | 271 mm | 83% | 0.1 m/s | 4.3 |
| 1988 | 19.6°C | 13.8°C | 8.1°C | 27.0°C | 1.7°C | 137 mm | 82% | 0.1 m/s | 5.1 |
| 1987 | 19.5°C | 13.5°C | 7.5°C | 28.5°C | 0.0°C | 58 mm | 82% | 0.1 m/s | 5.2 |
| 1986 | 20.6°C | 14.6°C | 8.5°C | 27.2°C | -1.6°C | 66 mm | 80% | 0.1 m/s | 6.1 |
| 1985 | 20.9°C | 14.6°C | 8.3°C | 27.0°C | -0.5°C | 140 mm | 74% | 0.1 m/s | 5.8 |
| 1984 | 17.5°C | 11.9°C | 6.3°C | 24.9°C | 0.6°C | 258 mm | 82% | 0.1 m/s | 4 |
| 1983 | 17.7°C | 12.0°C | 6.2°C | 24.0°C | -1.5°C | 136 mm | 83% | 0.1 m/s | — |
| 1982 | 20.5°C | 14.4°C | 8.4°C | 25.0°C | 2.3°C | 74 mm | 80% | 0.1 m/s | — |
| 1981 | 20.2°C | 13.4°C | 6.7°C | 26.4°C | -0.7°C | 129 mm | 76% | 0.1 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 19.8°C with lows near 8.1°C (mean 14°C), based on 45 years of NASA POWER data.
May averages 111 mm of rainfall in Middletown, a relatively wet time of year. The wettest on record was 271 mm in 1989.
The hottest May reached 31.4°C in 1991. The coldest dipped to -2.1°C in 2020.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.3°C. Daytime highs moved from 19.4°C to 20.3°C and overnight lows from 7.2°C to 8.8°C over the same span.
May is one of the warmer months of the year in Middletown and a relatively wet time of year, so plan for around 19.8°C daytime highs and 8.1°C at night.
Not quite — May is the 8th coolest month in Middletown, averaging 14°C.
For May in Middletown, pack light layers you can adjust through the day, with typical highs of 19.8°C and lows of 8.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 79% — 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 1989 with 271 mm. On average, May sees 111 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 Middletown 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.
