May is one of the warmer months of the year in Truro, with average highs near 14.3°C and lows around 3.9°C (mean 9.1°C). It is about average for rainfall, averaging 71 mm of rainfall and 82% relative humidity across the period.
May is one of the warmer months of the year in Truro. Across 45 years of records, the warmest May in Truro was 1989 — when the month averaged 12.5°C — while the coldest was 2019 at 6.7°C. Typical May days reach 14.3°C with nights near 3.9°C. The long-term May temperature trend is broadly flat.
May is about average for rainfall in Truro, averaging 71 mm of rainfall. The wettest May on record was 2005 with 165 mm, while the driest was 1992 at 34 mm.
Relative humidity in Truro during May averages 82%. The most humid May was 2011 at 89%, and the least humid was 1987 at 73%.
May receives about 5.1 kWh/m²/day of solar energy in Truro. The sunniest May was 1999 at 6.3 kWh/m²/day, and the cloudiest was 2011 at 3.7.
Average wind speed in Truro during May is 0.4 m/s. The windiest May was 2023 at 0.6 m/s, while the calmest was 2006 at 0.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 9.7°C | 8.7°C | 8.6°C | 9.3°C | 9.3°C | -0.4°C |
| Avg High | 15.1°C | 14.1°C | 13.7°C | 14.3°C | 14.6°C | -0.5°C |
| Avg Low | 4.3°C | 3.4°C | 3.5°C | 4.3°C | 4.1°C | -0.2°C |
| Avg Rain | 71 mm | 65 mm | 88 mm | 67 mm | 58 mm | -13 mm |
May temperatures in Truro have risen by about 0.4°C between 1981–1985 and 2021–2025.
May has ranged from a record low of -4°C (1991) to a record high of 26.4°C (1999).
Rainfall in May is about average for rainfall, averaging 71 mm, with a wettest year of 165 mm.
Daytime highs and overnight lows have shifted differently — highs fell about 0.1°C per decade while lows rose 0.1°C per decade, narrowing the gap between day and night.
A good time to visit Truro
May is a good time to visit Truro, with days averaging 14.3°C and nights around 3.9°C (mean 9.1°C, warmer than Truro'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 | 15.0°C | 9.9°C | 4.8°C | 23.7°C | -0.9°C | 61 mm | 82% | 0.5 m/s | 4.7 |
| 2024 | 15.3°C | 10.6°C | 5.8°C | 23.5°C | 0.9°C | 77 mm | 85% | 0.4 m/s | 5.3 |
| 2023 | 13.4°C | 8.1°C | 2.9°C | 26.0°C | -1.8°C | 47 mm | 80% | 0.6 m/s | 5.4 |
| 2022 | 15.4°C | 9.5°C | 3.7°C | 22.9°C | -4.0°C | 37 mm | 79% | 0.4 m/s | 6 |
| 2021 | 14.5°C | 9.2°C | 4.0°C | 24.5°C | 0.3°C | 75 mm | 81% | 0.5 m/s | 5.1 |
| 2020 | 14.0°C | 8.7°C | 3.3°C | 24.9°C | -1.7°C | 52 mm | 79% | 0.5 m/s | 5.4 |
| 2019 ❄️ | 11.0°C | 6.7°C | 2.4°C | 17.8°C | -1.6°C | 83 mm | 84% | 0.4 m/s | 4.6 |
| 2018 | 15.4°C | 9.4°C | 3.3°C | 22.8°C | -2.1°C | 72 mm | 79% | 0.4 m/s | 6 |
| 2017 | 13.7°C | 9.0°C | 4.3°C | 25.5°C | 0.3°C | 102 mm | 85% | 0.4 m/s | 4.9 |
| 2016 | 14.9°C | 9.9°C | 4.9°C | 24.2°C | -2.3°C | 64 mm | 83% | 0.4 m/s | 4.8 |
| 2015 | 15.8°C | 10.0°C | 4.1°C | 25.7°C | -2.3°C | 54 mm | 81% | 0.4 m/s | 5.6 |
| 2014 | 13.2°C | 8.2°C | 3.1°C | 22.0°C | -2.1°C | 40 mm | 83% | 0.4 m/s | 5.2 |
| 2013 | 14.9°C | 10.0°C | 5.1°C | 24.6°C | -0.6°C | 60 mm | 85% | 0.5 m/s | 5 |
| 2012 | 16.3°C | 10.9°C | 5.5°C | 22.0°C | -1.9°C | 61 mm | 81% | 0.4 m/s | 5.2 |
| 2011 | 13.9°C | 9.7°C | 5.6°C | 23.2°C | 0.9°C | 92 mm | 89% | 0.5 m/s | 3.7 |
| 2010 | 14.3°C | 9.6°C | 4.8°C | 24.2°C | 1.6°C | 44 mm | 82% | 0.5 m/s | 5.3 |
| 2009 | 15.2°C | 10.0°C | 4.9°C | 23.7°C | 0.2°C | 84 mm | 83% | 0.4 m/s | 4.8 |
| 2008 | 12.7°C | 8.1°C | 3.5°C | 19.4°C | 0.0°C | 117 mm | 85% | 0.5 m/s | 4.8 |
| 2007 | 12.7°C | 7.8°C | 2.9°C | 23.6°C | -1.9°C | 82 mm | 83% | 0.5 m/s | 4.8 |
| 2006 | 16.2°C | 10.5°C | 4.8°C | 22.4°C | -0.2°C | 73 mm | 82% | 0.3 m/s | 5.2 |
| 2005 🌧️ | 11.7°C | 7.6°C | 3.6°C | 19.9°C | -1.3°C | 165 mm | 85% | 0.5 m/s | 4.1 |
| 2004 | 13.8°C | 8.2°C | 2.6°C | 23.3°C | -1.5°C | 43 mm | 80% | 0.4 m/s | 4.6 |
| 2003 | 13.2°C | 8.0°C | 2.8°C | 24.6°C | -2.2°C | 60 mm | 83% | 0.4 m/s | 4.8 |
| 2002 | 13.8°C | 8.5°C | 3.1°C | 21.8°C | -2.8°C | 53 mm | 78% | 0.4 m/s | 5.8 |
| 2001 | 15.0°C | 9.4°C | 3.8°C | 23.2°C | -3.7°C | 131 mm | 82% | 0.4 m/s | 5.5 |
| 2000 | 12.5°C | 7.7°C | 2.9°C | 18.5°C | -0.9°C | 68 mm | 81% | 0.4 m/s | 4.8 |
| 1999 | 17.9°C | 11.6°C | 5.4°C | 26.4°C | -0.6°C | 39 mm | 78% | 0.4 m/s | 6.3 |
| 1998 | 17.1°C | 11.4°C | 5.8°C | 23.7°C | -1.0°C | 59 mm | 82% | 0.4 m/s | 5.6 |
| 1997 | 12.4°C | 7.7°C | 3.0°C | 17.8°C | -2.1°C | 77 mm | 82% | 0.4 m/s | 4.9 |
| 1996 | 12.2°C | 7.3°C | 2.5°C | 19.6°C | -4.0°C | 69 mm | 81% | 0.4 m/s | 4.5 |
| 1995 | 12.8°C | 7.6°C | 2.4°C | 19.5°C | -2.5°C | 42 mm | 81% | 0.4 m/s | 5 |
| 1994 | 12.9°C | 8.0°C | 3.2°C | 23.0°C | -0.7°C | 71 mm | 83% | 0.4 m/s | 4.7 |
| 1993 | 14.0°C | 8.8°C | 3.5°C | 21.4°C | -3.8°C | 48 mm | 83% | 0.4 m/s | 4.4 |
| 1992 | 14.9°C | 8.5°C | 2.1°C | 26.2°C | -2.6°C | 34 mm | 79% | 0.4 m/s | 5.4 |
| 1991 | 14.8°C | 8.9°C | 2.9°C | 24.4°C | -4.0°C | 70 mm | 78% | 0.4 m/s | 5.4 |
| 1990 | 12.2°C | 7.5°C | 2.8°C | 21.8°C | -2.0°C | 136 mm | 82% | 0.4 m/s | 4.4 |
| 1989 🔥 | 17.9°C | 12.5°C | 7.0°C | 24.0°C | 1.3°C | 76 mm | 83% | 0.4 m/s | 5 |
| 1988 | 15.9°C | 10.3°C | 4.8°C | 23.3°C | -1.6°C | 47 mm | 82% | 0.4 m/s | 5.2 |
| 1987 | 15.7°C | 9.4°C | 3.2°C | 23.5°C | -2.2°C | 36 mm | 73% | 0.4 m/s | 5.9 |
| 1986 | 15.1°C | 9.3°C | 3.6°C | 25.4°C | -3.9°C | 49 mm | 80% | 0.4 m/s | 5.4 |
| 1985 | 13.5°C | 8.1°C | 2.7°C | 23.0°C | -2.4°C | 90 mm | 82% | 0.4 m/s | 5.2 |
| 1984 | 14.0°C | 9.3°C | 4.7°C | 20.4°C | -1.3°C | 82 mm | 86% | 0.4 m/s | 4.2 |
| 1983 | 14.4°C | 9.6°C | 4.8°C | 18.6°C | -0.8°C | 113 mm | 84% | 0.4 m/s | — |
| 1982 | 13.3°C | 8.2°C | 3.0°C | 22.2°C | -1.6°C | 57 mm | 83% | 0.4 m/s | — |
| 1981 | 15.7°C | 10.4°C | 5.1°C | 23.2°C | -1.5°C | 91 mm | 84% | 0.4 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 14.3°C with lows near 3.9°C (mean 9.1°C), based on 45 years of NASA POWER data.
May averages 71 mm of rainfall in Truro, about average for rainfall. The wettest on record was 165 mm in 2005.
The hottest May reached 26.4°C in 1999. The coldest dipped to -4°C in 1991.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 0.4°C. Daytime highs moved from 14.2°C to 14.7°C and overnight lows from 4.1°C to 4.2°C over the same span.
May is one of the warmer months of the year in Truro and about average for rainfall, so plan for around 14.3°C daytime highs and 3.9°C at night.
Not quite — May is the 7th coolest month in Truro, averaging 9.1°C.
For May in Truro, pack warm layers and a jacket for chilly mornings, with typical highs of 14.3°C and lows of 3.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 82% — quite humid.
Average wind speed in May is 0.4 m/s. The windiest May on record averaged 0.6 m/s (2023).
The wettest May on record was 2005 with 165 mm. On average, May sees 71 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 Truro 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.
