May is one of the warmer months of the year in Derry, with average highs near 12.9°C and lows around 7°C (mean 10°C). It is one of the drier months, averaging 82 mm of rainfall and 85% relative humidity across the period.
May is one of the warmer months of the year in Derry. Across 45 years of records, the warmest May in Derry was 2024 — when the month averaged 12.1°C — while the coldest was 1996 at 7.7°C. Typical May days reach 12.9°C with nights near 7°C. The long-term trend is warming, about 0.3°C per decade.
May is one of the drier months in Derry, averaging 82 mm of rainfall. The wettest Mays on record were 1981 and 1986 with 149 mm, while the driest was 1991 at 26 mm.
Relative humidity in Derry during May averages 85%. The most humid May was 2014 at 88%, and the least humid was 1984 at 81%.
May receives about 4.6 kWh/m²/day of solar energy in Derry. The sunniest May was 2025 at 5.8 kWh/m²/day, and the cloudiest was 2014 at 3.8.
Average wind speed in Derry during May is 4 m/s. The windiest May was 2011 at 6.2 m/s, while the calmest was 1990 at 2.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 9.3°C | 9.8°C | 10.1°C | 9.8°C | 10.9°C | +1.6°C |
| Avg High | 12.3°C | 12.8°C | 13.0°C | 12.7°C | 13.9°C | +1.6°C |
| Avg Low | 6.4°C | 6.8°C | 7.2°C | 6.9°C | 7.8°C | +1.4°C |
| Avg Rain | 83 mm | 66 mm | 88 mm | 94 mm | 74 mm | -9 mm |
May temperatures in Derry have risen by about 1.7°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 0.9°C (1982) to a record high of 21.8°C (1990).
Rainfall in May is one of the drier months, averaging 82 mm, with a wettest year of 149 mm.
A good time to visit Derry
May is a good time to visit Derry, with days averaging 12.9°C and nights around 7°C (mean 10°C, warmer than Derry'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 | 15.3°C | 11.8°C | 8.4°C | 18.9°C | 5.2°C | 59 mm | 82% | 3.3 m/s | 5.8 |
| 2024 🔥 | 15.0°C | 12.1°C | 9.1°C | 19.4°C | 6.2°C | 69 mm | 87% | 3.3 m/s | 4.2 |
| 2023 | 14.4°C | 11.1°C | 7.8°C | 18.2°C | 5.4°C | 50 mm | 86% | 3.3 m/s | 4.8 |
| 2022 | 13.6°C | 11.0°C | 8.4°C | 16.8°C | 6.6°C | 102 mm | 86% | 4.6 m/s | 4.3 |
| 2021 | 11.6°C | 9.0°C | 6.3°C | 18.9°C | 2.2°C | 114 mm | 84% | 3.8 m/s | 4.8 |
| 2020 | 13.7°C | 10.4°C | 7.1°C | 20.2°C | 2.2°C | 52 mm | 83% | 4.1 m/s | 5.2 |
| 2019 | 12.2°C | 9.3°C | 6.3°C | 16.5°C | 2.1°C | 87 mm | 83% | 3.4 m/s | 4.2 |
| 2018 | 14.7°C | 11.2°C | 7.8°C | 21.2°C | 3.4°C | 70 mm | 86% | 3.8 m/s | 4.9 |
| 2017 | 14.9°C | 11.3°C | 7.7°C | 21.0°C | 4.1°C | 69 mm | 84% | 3.6 m/s | 5.3 |
| 2016 | 13.5°C | 10.3°C | 7.0°C | 19.0°C | 4.6°C | 65 mm | 85% | 3.9 m/s | 5 |
| 2015 | 10.6°C | 8.1°C | 5.7°C | 14.3°C | 2.3°C | 147 mm | 86% | 5 m/s | 4.1 |
| 2014 | 12.8°C | 10.4°C | 8.0°C | 16.5°C | 5.7°C | 129 mm | 88% | 3.6 m/s | 3.8 |
| 2013 | 11.1°C | 8.6°C | 6.0°C | 14.9°C | 1.9°C | 123 mm | 86% | 4.8 m/s | 4.4 |
| 2012 | 12.6°C | 9.6°C | 6.6°C | 21.4°C | 2.8°C | 70 mm | 85% | 3.7 m/s | 4.7 |
| 2011 | 12.2°C | 9.9°C | 7.6°C | 16.0°C | 4.5°C | 126 mm | 84% | 6.2 m/s | 4.5 |
| 2010 | 12.0°C | 9.3°C | 6.5°C | 19.9°C | 2.3°C | 59 mm | 84% | 3.5 m/s | 4.9 |
| 2009 | 12.8°C | 9.8°C | 6.8°C | 20.0°C | 4.1°C | 105 mm | 86% | 4.7 m/s | 4.6 |
| 2008 | 15.0°C | 11.5°C | 8.0°C | 18.7°C | 4.4°C | 30 mm | 84% | 3.5 m/s | 5.2 |
| 2007 | 12.6°C | 9.8°C | 7.0°C | 17.4°C | 4.0°C | 84 mm | 83% | 4.3 m/s | 5.3 |
| 2006 | 12.4°C | 9.6°C | 6.8°C | 19.0°C | 3.7°C | 126 mm | 85% | 4.6 m/s | 4.5 |
| 2005 | 11.7°C | 8.9°C | 6.2°C | 15.2°C | 2.3°C | 102 mm | 84% | 4.1 m/s | 4.6 |
| 2004 | 13.0°C | 10.1°C | 7.3°C | 16.6°C | 4.2°C | 61 mm | 86% | 3.6 m/s | 4.8 |
| 2003 | 12.0°C | 9.7°C | 7.3°C | 20.1°C | 3.1°C | 119 mm | 86% | 4.7 m/s | 3.9 |
| 2002 | 12.8°C | 10.1°C | 7.4°C | 18.2°C | 3.6°C | 128 mm | 86% | 4.1 m/s | 4.2 |
| 2001 | 14.4°C | 11.1°C | 7.9°C | 19.6°C | 4.4°C | 67 mm | 85% | 3.2 m/s | 4.7 |
| 2000 | 13.3°C | 10.1°C | 7.0°C | 19.5°C | 4.7°C | 55 mm | 84% | 3.7 m/s | 5.3 |
| 1999 | 13.2°C | 10.4°C | 7.6°C | 16.5°C | 4.7°C | 65 mm | 86% | 4.1 m/s | 4.3 |
| 1998 | 13.6°C | 10.6°C | 7.6°C | 20.1°C | 5.1°C | 59 mm | 87% | 3.7 m/s | 4.9 |
| 1997 | 13.4°C | 10.3°C | 7.2°C | 20.5°C | 2.4°C | 105 mm | 84% | 3.7 m/s | 4.6 |
| 1996 ❄️ | 10.6°C | 7.7°C | 4.9°C | 15.9°C | 1.3°C | 90 mm | 83% | 3.9 m/s | 4.4 |
| 1995 | 11.8°C | 9.1°C | 6.5°C | 18.0°C | 2.5°C | 73 mm | 85% | 4.3 m/s | 4.4 |
| 1994 | 11.8°C | 8.8°C | 5.7°C | 17.1°C | 3.4°C | 47 mm | 83% | 4.3 m/s | 4.7 |
| 1993 | 12.5°C | 9.4°C | 6.3°C | 16.5°C | 1.7°C | 88 mm | 85% | 4 m/s | 4 |
| 1992 | 14.0°C | 10.7°C | 7.4°C | 20.0°C | 2.5°C | 54 mm | 86% | 4.9 m/s | 4.6 |
| 1991 | 12.8°C | 9.8°C | 6.8°C | 16.5°C | 3.2°C | 26 mm | 87% | 3.7 m/s | 4.3 |
| 1990 | 14.7°C | 11.4°C | 8.1°C | 21.8°C | 5.4°C | 54 mm | 84% | 2.8 m/s | 4.8 |
| 1989 | 13.5°C | 10.0°C | 6.6°C | 20.1°C | 4.1°C | 38 mm | 84% | 3.9 m/s | 5 |
| 1988 | 13.1°C | 9.9°C | 6.7°C | 17.8°C | 3.6°C | 56 mm | 84% | 4 m/s | 4.5 |
| 1987 | 11.9°C | 9.1°C | 6.3°C | 16.0°C | 3.6°C | 55 mm | 84% | 4.4 m/s | 4.3 |
| 1986 | 11.2°C | 8.8°C | 6.4°C | 14.1°C | 3.8°C | 149 mm | 87% | 5.6 m/s | 4 |
| 1985 | 12.2°C | 9.1°C | 6.0°C | 17.2°C | 3.1°C | 84 mm | 84% | 3.4 m/s | 4.3 |
| 1984 | 12.5°C | 9.2°C | 5.9°C | 17.2°C | 3.0°C | 34 mm | 81% | 3.1 m/s | 5.2 |
| 1983 | 11.4°C | 8.7°C | 6.1°C | 15.4°C | 3.8°C | 84 mm | 85% | 4 m/s | — |
| 1982 | 12.5°C | 9.5°C | 6.5°C | 19.0°C | 0.9°C | 98 mm | 84% | 4.2 m/s | — |
| 1981 🌧️ | 12.7°C | 9.8°C | 7.0°C | 17.8°C | 2.2°C | 149 mm | 86% | 3.7 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 12.9°C with lows near 7°C (mean 10°C), based on 45 years of NASA POWER data.
May averages 82 mm of rainfall in Derry, one of the drier months. The wettest on record was 149 mm in 1981.
The hottest May reached 21.8°C in 1990. The coldest dipped to 0.9°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.7°C. Daytime highs moved from 12.3°C to 14°C and overnight lows from 6.3°C to 8°C over the same span.
May is one of the warmer months of the year in Derry and one of the drier months, so plan for around 12.9°C daytime highs and 7°C at night.
Not quite — May is the 8th coolest month in Derry, averaging 10°C.
For May in Derry, pack warm layers and a jacket for chilly mornings, with typical highs of 12.9°C and lows of 7°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 85% — quite humid.
Average wind speed in May is 4 m/s. The windiest May on record averaged 6.2 m/s (2011).
The wettest May on record was 1981 with 149 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 Derry 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.
