May is one of the warmer months of the year in The Mumbles, with average highs near 14.4°C and lows around 8.6°C (mean 11.5°C). It is one of the drier months, averaging 67 mm of rainfall and 83% relative humidity across the period.
May is one of the warmer months of the year in The Mumbles. Across 45 years of records, the warmest May in The Mumbles was 2025 — when the month averaged 13.3°C — while the coldest was 1996 at 9.3°C. Typical May days reach 14.4°C with nights near 8.6°C. The long-term trend is warming, about 0.3°C per decade.
May is one of the drier months in The Mumbles, averaging 67 mm of rainfall. The wettest May on record was 2021 with 167 mm, while the driest was 1991 at 10 mm.
Relative humidity in The Mumbles during May averages 83%. The most humid May was 1981 at 87%, and the least humid were 1990 and 2020 at 79%.
May receives about 5 kWh/m²/day of solar energy in The Mumbles. The sunniest May was 2020 at 6.4 kWh/m²/day, and the cloudiest was 1993 at 4.2.
Average wind speed in The Mumbles during May is 3.9 m/s. The windiest May was 2011 at 5.4 m/s, while the calmest were 2004 and 2018 at 2.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 10.8°C | 11.5°C | 11.7°C | 11.5°C | 12.3°C | +1.5°C |
| Avg High | 13.7°C | 14.6°C | 14.4°C | 14.3°C | 15.4°C | +1.7°C |
| Avg Low | 7.9°C | 8.4°C | 8.9°C | 8.6°C | 9.3°C | +1.4°C |
| Avg Rain | 61 mm | 54 mm | 82 mm | 69 mm | 70 mm | +9 mm |
May temperatures in The Mumbles have risen by about 1.9°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 2.4°C (1996) to a record high of 23.4°C (1989).
Rainfall in May is one of the drier months, averaging 67 mm, with a wettest year of 167 mm.
A good time to visit The Mumbles
May is a good time to visit The Mumbles, with days averaging 14.4°C and nights around 8.6°C (mean 11.5°C, close to The Mumbles's yearly average) and moderate 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 🔥 | 16.7°C | 13.3°C | 10.0°C | 20.6°C | 5.3°C | 38 mm | 81% | 3.5 m/s | 5.8 |
| 2024 | 16.0°C | 13.1°C | 10.3°C | 19.9°C | 7.3°C | 92 mm | 84% | 3.1 m/s | 4.8 |
| 2023 | 15.9°C | 12.6°C | 9.2°C | 18.8°C | 6.9°C | 41 mm | 83% | 3.4 m/s | 5.8 |
| 2022 | 15.2°C | 12.5°C | 9.8°C | 18.5°C | 7.9°C | 69 mm | 85% | 3.5 m/s | 5 |
| 2021 🌧️ | 12.6°C | 10.3°C | 8.1°C | 18.5°C | 4.7°C | 167 mm | 83% | 4.3 m/s | 4.7 |
| 2020 | 15.8°C | 12.2°C | 8.6°C | 21.3°C | 3.8°C | 14 mm | 79% | 3.7 m/s | 6.4 |
| 2019 | 14.4°C | 11.3°C | 8.3°C | 16.9°C | 4.5°C | 41 mm | 82% | 3.3 m/s | 5.1 |
| 2018 | 15.7°C | 12.4°C | 9.2°C | 21.4°C | 4.8°C | 56 mm | 83% | 2.8 m/s | 5.4 |
| 2017 | 15.6°C | 12.5°C | 9.4°C | 20.8°C | 5.6°C | 56 mm | 85% | 3.6 m/s | 5 |
| 2016 | 15.1°C | 12.0°C | 8.9°C | 18.1°C | 5.1°C | 71 mm | 84% | 3.4 m/s | 5.2 |
| 2015 | 13.1°C | 10.8°C | 8.5°C | 17.2°C | 6.0°C | 109 mm | 84% | 4.8 m/s | 4.9 |
| 2014 | 14.5°C | 12.0°C | 9.5°C | 17.7°C | 6.5°C | 97 mm | 84% | 3.6 m/s | 4.6 |
| 2013 | 12.6°C | 9.8°C | 7.1°C | 16.6°C | 4.3°C | 86 mm | 83% | 4.4 m/s | 4.9 |
| 2012 | 14.4°C | 11.5°C | 8.6°C | 21.8°C | 4.1°C | 65 mm | 83% | 3.5 m/s | 5.1 |
| 2011 | 14.1°C | 11.6°C | 9.2°C | 17.1°C | 4.9°C | 63 mm | 83% | 5.4 m/s | 4.9 |
| 2010 | 13.8°C | 10.8°C | 7.7°C | 21.3°C | 3.8°C | 43 mm | 82% | 3.1 m/s | 5.1 |
| 2009 | 14.2°C | 11.5°C | 8.8°C | 19.9°C | 5.9°C | 56 mm | 84% | 4.7 m/s | 5.1 |
| 2008 | 15.8°C | 12.7°C | 9.6°C | 22.0°C | 6.0°C | 82 mm | 85% | 3.7 m/s | 4.6 |
| 2007 | 14.4°C | 11.8°C | 9.3°C | 17.6°C | 6.7°C | 122 mm | 84% | 4.5 m/s | 4.9 |
| 2006 | 14.1°C | 11.5°C | 8.9°C | 18.9°C | 6.3°C | 124 mm | 86% | 4.2 m/s | 4.6 |
| 2005 | 13.5°C | 10.8°C | 8.0°C | 19.6°C | 4.2°C | 42 mm | 82% | 4.4 m/s | 5.3 |
| 2004 | 14.9°C | 12.0°C | 9.1°C | 19.8°C | 6.0°C | 47 mm | 83% | 2.8 m/s | 5 |
| 2003 | 13.8°C | 11.5°C | 9.1°C | 21.3°C | 6.3°C | 81 mm | 84% | 4.5 m/s | 4.6 |
| 2002 | 13.9°C | 11.4°C | 8.9°C | 18.9°C | 5.2°C | 131 mm | 84% | 4.7 m/s | 4.5 |
| 2001 | 15.2°C | 11.8°C | 8.4°C | 19.4°C | 4.2°C | 42 mm | 84% | 3.3 m/s | 5.1 |
| 2000 | 14.4°C | 11.5°C | 8.6°C | 19.4°C | 6.0°C | 93 mm | 85% | 4 m/s | 4.8 |
| 1999 | 15.0°C | 12.5°C | 9.9°C | 18.7°C | 7.1°C | 57 mm | 86% | 4.1 m/s | 4.3 |
| 1998 | 15.9°C | 12.7°C | 9.5°C | 20.9°C | 5.0°C | 33 mm | 83% | 3.6 m/s | 6.2 |
| 1997 | 14.6°C | 11.4°C | 8.3°C | 19.7°C | 3.4°C | 72 mm | 83% | 3.9 m/s | 5 |
| 1996 ❄️ | 12.2°C | 9.3°C | 6.3°C | 17.1°C | 2.4°C | 97 mm | 80% | 4.5 m/s | 4.5 |
| 1995 | 14.3°C | 11.2°C | 8.1°C | 21.6°C | 3.7°C | 53 mm | 80% | 3.7 m/s | 5 |
| 1994 | 13.4°C | 10.6°C | 7.9°C | 16.1°C | 4.5°C | 69 mm | 83% | 3.6 m/s | 4.6 |
| 1993 | 14.0°C | 11.1°C | 8.1°C | 19.0°C | 4.1°C | 92 mm | 83% | 4.7 m/s | 4.2 |
| 1992 | 15.9°C | 12.5°C | 9.1°C | 21.5°C | 5.2°C | 33 mm | 82% | 3.8 m/s | 5.8 |
| 1991 | 14.3°C | 11.1°C | 7.9°C | 18.0°C | 4.1°C | 10 mm | 83% | 3.4 m/s | 4.6 |
| 1990 | 16.3°C | 12.7°C | 9.2°C | 22.2°C | 6.8°C | 25 mm | 79% | 3.1 m/s | 5.5 |
| 1989 | 16.4°C | 12.9°C | 9.4°C | 23.4°C | 6.3°C | 11 mm | 82% | 3 m/s | 5.6 |
| 1988 | 14.5°C | 11.5°C | 8.5°C | 20.1°C | 6.5°C | 62 mm | 83% | 3.8 m/s | 5 |
| 1987 | 13.2°C | 10.2°C | 7.2°C | 17.7°C | 4.0°C | 36 mm | 82% | 4.1 m/s | 4.5 |
| 1986 | 12.5°C | 10.0°C | 7.6°C | 15.8°C | 5.0°C | 80 mm | 86% | 5.1 m/s | 4.5 |
| 1985 | 13.7°C | 10.7°C | 7.6°C | 17.3°C | 4.1°C | 51 mm | 83% | 3.5 m/s | 4.6 |
| 1984 | 13.5°C | 10.2°C | 7.0°C | 18.2°C | 3.6°C | 53 mm | 80% | 3.6 m/s | 4.7 |
| 1983 | 12.2°C | 9.7°C | 7.3°C | 15.9°C | 5.0°C | 111 mm | 86% | 3.9 m/s | — |
| 1982 | 13.9°C | 10.9°C | 7.9°C | 19.2°C | 3.4°C | 30 mm | 81% | 3.6 m/s | — |
| 1981 | 13.3°C | 10.9°C | 8.5°C | 17.7°C | 5.2°C | 117 mm | 87% | 4.1 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 14.4°C with lows near 8.6°C (mean 11.5°C), based on 45 years of NASA POWER data.
May averages 67 mm of rainfall in The Mumbles, one of the drier months. The wettest on record was 167 mm in 2021.
The hottest May reached 23.4°C in 1989. The coldest dipped to 2.4°C in 1996.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.9°C. Daytime highs moved from 13.3°C to 15.3°C and overnight lows from 7.7°C to 9.5°C over the same span.
May is one of the warmer months of the year in The Mumbles and one of the drier months, so plan for around 14.4°C daytime highs and 8.6°C at night.
Not quite — May is the 7th coolest month in The Mumbles, averaging 11.5°C.
For May in The Mumbles, pack light layers you can adjust through the day, with typical highs of 14.4°C and lows of 8.6°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 83% — quite humid.
Average wind speed in May is 3.9 m/s. The windiest May on record averaged 5.4 m/s (2011).
The wettest May on record was 2021 with 167 mm. On average, May sees 67 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 The Mumbles 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.
