July is one of the warmer months of the year in Swansea, with average highs near 18.8°C and lows around 13.5°C (mean 16.2°C). It is one of the drier months, averaging 74 mm of rainfall and 84% relative humidity across the period.
July is one of the warmer months of the year in Swansea. Across 45 years of records, the warmest July in Swansea was 1983 — when the month averaged 18.3°C — while the coldest was 1988 at 14.3°C. Typical July days reach 18.8°C with nights near 13.5°C. The long-term trend is warming, about 0.2°C per decade.
July is one of the drier months in Swansea, averaging 74 mm of rainfall. The wettest July on record was 2009 with 185 mm, while the driest was 1999 at 23 mm.
Relative humidity in Swansea during July averages 84%. The most humid July was 1988 at 86%, and the least humid was 1990 at 79%.
July receives about 5.1 kWh/m²/day of solar energy in Swansea. The sunniest July was 2013 at 6.1 kWh/m²/day, and the cloudiest was 2023 at 4.4.
Average wind speed in Swansea during July is 3.7 m/s. The windiest July was 1988 at 5.2 m/s, while the calmest was 1983 at 2.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 16.0°C | 16.0°C | 15.9°C | 16.3°C | 16.6°C | +0.6°C |
| Avg High | 18.7°C | 18.8°C | 18.4°C | 19.0°C | 19.2°C | +0.5°C |
| Avg Low | 13.2°C | 13.2°C | 13.4°C | 13.7°C | 14.0°C | +0.8°C |
| Avg Rain | 60 mm | 59 mm | 99 mm | 73 mm | 82 mm | +22 mm |
July temperatures in Swansea have risen by about 0.6°C between 1981–1985 and 2021–2025.
July has ranged from a record low of 9.1°C (1996) to a record high of 27.3°C (2006).
Rainfall in July is one of the drier months, averaging 74 mm, with a wettest year of 185 mm.
One of the best times to visit Swansea
July is one of the best times to visit Swansea. Expect days averaging 18.8°C and nights around 13.5°C (mean 16.2°C) — warmer than Swansea's yearly average — with moderate rainfall (74 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 | 20.2°C | 17.6°C | 15.0°C | 26.7°C | 12.8°C | 46 mm | 83% | 3.5 m/s | 5.6 |
| 2024 | 18.6°C | 16.0°C | 13.4°C | 23.4°C | 11.4°C | 94 mm | 84% | 3.4 m/s | 5 |
| 2023 | 18.2°C | 16.0°C | 13.9°C | 21.5°C | 12.3°C | 136 mm | 84% | 4.9 m/s | 4.4 |
| 2022 | 20.2°C | 17.2°C | 14.1°C | 26.9°C | 11.4°C | 28 mm | 82% | 3.2 m/s | 5.4 |
| 2021 | 20.3°C | 17.4°C | 14.4°C | 26.2°C | 12.0°C | 105 mm | 84% | 3 m/s | 5.3 |
| 2020 | 17.7°C | 15.4°C | 13.1°C | 21.9°C | 10.0°C | 84 mm | 85% | 4.5 m/s | 4.8 |
| 2019 | 19.8°C | 17.0°C | 14.1°C | 24.7°C | 11.0°C | 42 mm | 83% | 3.2 m/s | 5.5 |
| 2018 | 21.0°C | 17.9°C | 14.9°C | 24.3°C | 13.2°C | 47 mm | 82% | 2.8 m/s | 5.8 |
| 2017 | 18.7°C | 16.2°C | 13.7°C | 22.4°C | 12.2°C | 118 mm | 84% | 4 m/s | 5 |
| 2016 | 18.5°C | 16.0°C | 13.6°C | 25.1°C | 11.2°C | 51 mm | 86% | 4.1 m/s | 4.9 |
| 2015 | 17.8°C | 15.4°C | 13.0°C | 22.1°C | 10.5°C | 100 mm | 83% | 4.5 m/s | 4.9 |
| 2014 | 19.8°C | 17.0°C | 14.2°C | 23.6°C | 12.0°C | 36 mm | 83% | 3.3 m/s | 5.8 |
| 2013 | 20.6°C | 17.4°C | 14.3°C | 24.7°C | 10.9°C | 42 mm | 83% | 2.9 m/s | 6.1 |
| 2012 | 17.3°C | 15.0°C | 12.6°C | 23.4°C | 10.3°C | 119 mm | 85% | 3.9 m/s | 4.8 |
| 2011 | 17.9°C | 15.3°C | 12.7°C | 20.6°C | 10.6°C | 75 mm | 82% | 3.4 m/s | 4.9 |
| 2010 | 18.5°C | 16.2°C | 14.0°C | 20.8°C | 12.4°C | 100 mm | 86% | 4.1 m/s | 4.7 |
| 2009 🌧️ | 17.9°C | 15.8°C | 13.7°C | 24.5°C | 12.1°C | 185 mm | 85% | 4.8 m/s | 4.7 |
| 2008 | 18.0°C | 15.6°C | 13.1°C | 23.0°C | 10.4°C | 124 mm | 86% | 4.3 m/s | 4.8 |
| 2007 | 17.2°C | 15.1°C | 13.0°C | 18.8°C | 11.0°C | 175 mm | 85% | 4.7 m/s | 4.7 |
| 2006 | 21.3°C | 18.1°C | 14.9°C | 27.3°C | 12.2°C | 39 mm | 82% | 3 m/s | 5.9 |
| 2005 | 19.0°C | 16.4°C | 13.8°C | 25.1°C | 11.4°C | 79 mm | 85% | 3.4 m/s | 4.9 |
| 2004 | 17.5°C | 15.1°C | 12.8°C | 20.1°C | 10.7°C | 64 mm | 85% | 3.8 m/s | 4.7 |
| 2003 | 19.1°C | 16.5°C | 13.9°C | 26.0°C | 11.3°C | 105 mm | 85% | 3.8 m/s | 4.5 |
| 2002 | 17.3°C | 14.9°C | 12.5°C | 21.2°C | 10.5°C | 69 mm | 86% | 3.5 m/s | 4.8 |
| 2001 | 18.7°C | 16.1°C | 13.6°C | 24.6°C | 10.7°C | 86 mm | 84% | 3.4 m/s | 4.7 |
| 2000 | 18.0°C | 15.5°C | 12.9°C | 21.7°C | 11.0°C | 69 mm | 85% | 3.4 m/s | 5 |
| 1999 | 19.6°C | 16.6°C | 13.6°C | 23.4°C | 11.1°C | 23 mm | 83% | 3.5 m/s | 5.9 |
| 1998 | 17.3°C | 15.2°C | 13.0°C | 19.5°C | 11.4°C | 74 mm | 86% | 4.6 m/s | 4.7 |
| 1997 | 18.8°C | 16.0°C | 13.1°C | 23.0°C | 9.7°C | 38 mm | 83% | 3.1 m/s | 5.4 |
| 1996 | 18.5°C | 15.6°C | 12.6°C | 22.8°C | 9.1°C | 47 mm | 83% | 3.6 m/s | 5.5 |
| 1995 | 20.0°C | 17.1°C | 14.1°C | 25.8°C | 10.5°C | 47 mm | 85% | 3.4 m/s | 5.2 |
| 1994 | 19.1°C | 16.1°C | 13.1°C | 22.7°C | 11.3°C | 47 mm | 84% | 2.8 m/s | 5.9 |
| 1993 | 17.2°C | 15.0°C | 12.7°C | 19.9°C | 10.0°C | 98 mm | 85% | 4.5 m/s | 5.1 |
| 1992 | 18.9°C | 16.1°C | 13.4°C | 21.4°C | 11.3°C | 86 mm | 84% | 3.6 m/s | 4.6 |
| 1991 | 18.5°C | 16.0°C | 13.5°C | 23.1°C | 11.5°C | 83 mm | 86% | 4 m/s | 5 |
| 1990 | 19.9°C | 16.6°C | 13.3°C | 24.7°C | 9.6°C | 46 mm | 79% | 3.9 m/s | 5.9 |
| 1989 | 20.5°C | 17.3°C | 14.2°C | 24.0°C | 11.3°C | 55 mm | 82% | 3.1 m/s | 5.7 |
| 1988 ❄️ | 16.3°C | 14.3°C | 12.3°C | 18.9°C | 10.5°C | 147 mm | 86% | 5.2 m/s | 4.5 |
| 1987 | 18.4°C | 15.8°C | 13.1°C | 23.3°C | 10.5°C | 53 mm | 83% | 3.3 m/s | 4.7 |
| 1986 | 17.5°C | 15.0°C | 12.5°C | 20.9°C | 9.9°C | 56 mm | 85% | 3.6 m/s | 4.7 |
| 1985 | 18.0°C | 15.4°C | 12.8°C | 22.9°C | 10.5°C | 78 mm | 84% | 3.7 m/s | 5 |
| 1984 | 19.5°C | 16.2°C | 12.9°C | 22.7°C | 9.3°C | 32 mm | 80% | 3.1 m/s | 5.8 |
| 1983 🔥 | 21.8°C | 18.3°C | 14.8°C | 26.3°C | 10.3°C | 30 mm | 83% | 2.3 m/s | — |
| 1982 | 19.1°C | 16.1°C | 13.1°C | 22.1°C | 11.0°C | 51 mm | 83% | 3.3 m/s | — |
| 1981 | 17.6°C | 15.2°C | 12.8°C | 21.5°C | 11.2°C | 41 mm | 85% | 4 m/s | — |
Actual recorded July data for each year, 1981–2025 — sourced from NASA POWER.
The average high in July is around 18.8°C with lows near 13.5°C (mean 16.2°C), based on 45 years of NASA POWER data.
July averages 74 mm of rainfall in Swansea, one of the drier months. The wettest on record was 185 mm in 2009.
The hottest July reached 27.3°C in 2006. The coldest dipped to 9.1°C in 1996.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average July temperatures have risen by about 0.6°C. Daytime highs moved from 19.2°C to 19.5°C and overnight lows from 13.3°C to 14.2°C over the same span.
July is one of the warmer months of the year in Swansea and one of the drier months, so plan for around 18.8°C daytime highs and 13.5°C at night.
Not quite — July is the 11th coolest month in Swansea, averaging 16.2°C.
For July in Swansea, pack light layers you can adjust through the day, with typical highs of 18.8°C and lows of 13.5°C. Bring an umbrella or light rain jacket too.
Relative humidity in July averages 84% — quite humid.
Average wind speed in July is 3.7 m/s. The windiest July on record averaged 5.2 m/s (1988).
The wettest July on record was 2009 with 185 mm. On average, July sees 74 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 July, 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 July specifically, along with year-by-year records and how the month has changed over the decades.
