June is one of the warmer months of the year in Swansea, with average highs near 17°C and lows around 11.4°C (mean 14.2°C). It is one of the drier months, averaging 71 mm of rainfall and 83% relative humidity across the period.
June is one of the warmer months of the year in Swansea. Across 45 years of records, the warmest June in Swansea was 2023 — when the month averaged 16.6°C — while the coldest was 1991 at 12.2°C. Typical June days reach 17°C with nights near 11.4°C. The long-term trend is warming, about 0.4°C per decade.
June is one of the drier months in Swansea, averaging 71 mm of rainfall. The wettest June on record was 2012 with 164 mm, while the driest was 1995 at 20 mm.
Relative humidity in Swansea during June averages 83%. The most humid June was 2016 at 86%, and the least humid was 1992 at 80%.
June receives about 5.3 kWh/m²/day of solar energy in Swansea. The sunniest Junes were 2010 and 2018 at 6.2 kWh/m²/day, and the cloudiest were 1997 and 2012 at 4.2.
Average wind speed in Swansea during June is 3.7 m/s. The windiest June was 1998 at 4.7 m/s, while the calmest was 2006 at 2.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 13.7°C | 13.7°C | 14.4°C | 14.4°C | 15.1°C | +1.4°C |
| Avg High | 16.5°C | 16.5°C | 17.1°C | 17.1°C | 18.0°C | +1.5°C |
| Avg Low | 10.9°C | 10.9°C | 11.7°C | 11.7°C | 12.2°C | +1.3°C |
| Avg Rain | 63 mm | 72 mm | 63 mm | 82 mm | 73 mm | +10 mm |
June temperatures in Swansea have risen by about 1.6°C between 1981–1985 and 2021–2025.
June has ranged from a record low of 6.1°C (1989) to a record high of 25.5°C (2017).
Rainfall in June is one of the drier months, averaging 71 mm, with a wettest year of 164 mm.
One of the best times to visit Swansea
June is one of the best times to visit Swansea. Expect days averaging 17°C and nights around 11.4°C (mean 14.2°C) — warmer than Swansea's yearly average — with moderate rainfall (71 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 18.4°C | 15.8°C | 13.2°C | 23.7°C | 10.0°C | 102 mm | 85% | 4 m/s | 5.7 |
| 2024 | 16.7°C | 14.0°C | 11.2°C | 22.5°C | 8.3°C | 33 mm | 82% | 3.6 m/s | 5.8 |
| 2023 🔥 | 19.9°C | 16.6°C | 13.2°C | 23.4°C | 8.5°C | 38 mm | 82% | 3.2 m/s | 6 |
| 2022 | 17.7°C | 14.8°C | 11.8°C | 22.6°C | 9.7°C | 83 mm | 81% | 3.7 m/s | 5.7 |
| 2021 | 17.8°C | 14.8°C | 11.8°C | 22.2°C | 9.2°C | 38 mm | 85% | 3 m/s | 5.3 |
| 2020 | 17.4°C | 14.6°C | 11.8°C | 25.1°C | 7.8°C | 145 mm | 83% | 4 m/s | 5.2 |
| 2019 | 16.5°C | 13.9°C | 11.3°C | 21.7°C | 8.6°C | 121 mm | 85% | 4 m/s | 4.7 |
| 2018 | 19.1°C | 15.9°C | 12.7°C | 23.9°C | 9.6°C | 22 mm | 81% | 3.1 m/s | 6.2 |
| 2017 | 17.8°C | 15.3°C | 12.7°C | 25.5°C | 10.1°C | 91 mm | 85% | 4.3 m/s | 5.1 |
| 2016 | 17.4°C | 14.9°C | 12.4°C | 20.7°C | 8.3°C | 115 mm | 86% | 3.4 m/s | 4.6 |
| 2015 | 16.5°C | 13.7°C | 10.8°C | 22.4°C | 7.2°C | 59 mm | 83% | 4.1 m/s | 5.9 |
| 2014 | 17.9°C | 15.0°C | 12.1°C | 20.9°C | 9.8°C | 59 mm | 82% | 2.8 m/s | 5.8 |
| 2013 | 16.2°C | 13.5°C | 10.7°C | 20.2°C | 8.0°C | 46 mm | 84% | 4.2 m/s | 5.2 |
| 2012 🌧️ | 15.8°C | 13.6°C | 11.4°C | 18.9°C | 7.8°C | 164 mm | 86% | 4.6 m/s | 4.2 |
| 2011 | 15.8°C | 13.4°C | 11.0°C | 21.6°C | 8.0°C | 105 mm | 83% | 4.3 m/s | 5.3 |
| 2010 | 17.8°C | 14.7°C | 11.6°C | 20.8°C | 8.7°C | 40 mm | 83% | 2.8 m/s | 6.2 |
| 2009 | 17.7°C | 14.8°C | 11.9°C | 23.1°C | 8.6°C | 83 mm | 82% | 2.8 m/s | 5.6 |
| 2008 | 16.4°C | 13.8°C | 11.2°C | 20.0°C | 8.5°C | 50 mm | 83% | 4.1 m/s | 5.4 |
| 2007 | 17.5°C | 14.9°C | 12.3°C | 21.8°C | 10.7°C | 113 mm | 86% | 3.4 m/s | 4.7 |
| 2006 | 18.2°C | 15.2°C | 12.1°C | 22.5°C | 7.5°C | 36 mm | 83% | 2.7 m/s | 6 |
| 2005 | 17.4°C | 14.7°C | 12.0°C | 21.0°C | 8.3°C | 80 mm | 85% | 3.4 m/s | 5.3 |
| 2004 | 17.0°C | 14.5°C | 12.0°C | 20.8°C | 9.0°C | 56 mm | 84% | 4 m/s | 5.5 |
| 2003 | 17.7°C | 14.8°C | 11.9°C | 20.9°C | 9.8°C | 67 mm | 84% | 3.5 m/s | 5.4 |
| 2002 | 15.4°C | 13.0°C | 10.7°C | 18.2°C | 8.2°C | 58 mm | 85% | 4.2 m/s | 4.9 |
| 2001 | 16.5°C | 13.7°C | 10.9°C | 23.0°C | 7.5°C | 32 mm | 82% | 3.4 m/s | 5.3 |
| 2000 | 16.8°C | 14.2°C | 11.5°C | 21.7°C | 8.9°C | 54 mm | 85% | 3.6 m/s | 4.7 |
| 1999 | 16.0°C | 13.3°C | 10.7°C | 20.3°C | 7.6°C | 80 mm | 83% | 3.5 m/s | 5.4 |
| 1998 | 16.1°C | 13.7°C | 11.3°C | 21.8°C | 7.8°C | 136 mm | 86% | 4.7 m/s | 4.4 |
| 1997 | 16.3°C | 13.6°C | 11.0°C | 19.4°C | 8.9°C | 115 mm | 83% | 4.6 m/s | 4.2 |
| 1996 | 16.9°C | 13.6°C | 10.3°C | 21.7°C | 7.3°C | 32 mm | 82% | 3.2 m/s | 5.9 |
| 1995 | 16.9°C | 13.7°C | 10.5°C | 25.2°C | 7.7°C | 20 mm | 82% | 3.8 m/s | 5.6 |
| 1994 | 16.2°C | 13.5°C | 10.7°C | 20.9°C | 7.7°C | 46 mm | 85% | 4.2 m/s | 5.8 |
| 1993 | 17.5°C | 14.5°C | 11.4°C | 21.4°C | 8.9°C | 96 mm | 84% | 3.1 m/s | 5.6 |
| 1992 | 18.5°C | 15.0°C | 11.6°C | 22.3°C | 9.1°C | 28 mm | 80% | 2.9 m/s | 5.7 |
| 1991 ❄️ | 14.6°C | 12.2°C | 9.9°C | 17.0°C | 6.6°C | 100 mm | 84% | 4.6 m/s | 4.5 |
| 1990 | 15.8°C | 13.4°C | 11.1°C | 19.1°C | 9.3°C | 69 mm | 83% | 4.1 m/s | 4.5 |
| 1989 | 17.3°C | 14.1°C | 11.0°C | 24.1°C | 6.1°C | 47 mm | 80% | 3.4 m/s | 5.4 |
| 1988 | 17.4°C | 14.4°C | 11.4°C | 21.3°C | 8.5°C | 44 mm | 83% | 3.2 m/s | 5.5 |
| 1987 | 15.1°C | 12.6°C | 10.1°C | 19.4°C | 6.7°C | 75 mm | 84% | 3.8 m/s | 4.7 |
| 1986 | 17.2°C | 14.0°C | 10.7°C | 23.8°C | 6.5°C | 67 mm | 84% | 3.7 m/s | 5.2 |
| 1985 | 15.2°C | 12.6°C | 10.0°C | 19.3°C | 6.7°C | 107 mm | 83% | 4.2 m/s | 5.1 |
| 1984 | 17.2°C | 14.0°C | 10.8°C | 23.0°C | 7.4°C | 26 mm | 82% | 3.2 m/s | 5.6 |
| 1983 | 16.3°C | 13.5°C | 10.7°C | 21.3°C | 7.6°C | 47 mm | 85% | 3.4 m/s | — |
| 1982 | 17.7°C | 14.9°C | 12.2°C | 21.8°C | 8.7°C | 107 mm | 83% | 3.2 m/s | — |
| 1981 | 15.5°C | 13.1°C | 10.8°C | 19.5°C | 8.6°C | 52 mm | 84% | 4.3 m/s | — |
Actual recorded June data for each year, 1981–2025 — sourced from NASA POWER.
The average high in June is around 17°C with lows near 11.4°C (mean 14.2°C), based on 45 years of NASA POWER data.
June averages 71 mm of rainfall in Swansea, one of the drier months. The wettest on record was 164 mm in 2012.
The hottest June reached 25.5°C in 2017. The coldest dipped to 6.1°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average June temperatures have risen by about 1.6°C. Daytime highs moved from 16.4°C to 18.1°C and overnight lows from 10.9°C to 12.2°C over the same span.
June is one of the warmer months of the year in Swansea and one of the drier months, so plan for around 17°C daytime highs and 11.4°C at night.
Not quite — June is the 9th coolest month in Swansea, averaging 14.2°C.
For June in Swansea, pack light layers you can adjust through the day, with typical highs of 17°C and lows of 11.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in June averages 83% — quite humid.
Average wind speed in June is 3.7 m/s. The windiest June on record averaged 4.7 m/s (1998).
The wettest June on record was 2012 with 164 mm. On average, June 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 Swansea behaves each June, 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 June specifically, along with year-by-year records and how the month has changed over the decades.
