Swansea in Summer
In summer (June, July and August), Swansea sees average daytime highs around 17°C and overnight lows near 14°C, with 266 mm of rain over about 40 wet days across the season. It is the warmest season of the year and the 3rd-wettest season.
Over the season highs climb from about 15°C in early June to 18°C by late August. The sky is clear or mostly clear about 20% of the time across summer, and the air most often feels dry.
Summer is Swansea's best season of the year to visit on our travel score. For the whole year in context, see Swansea's year-round climate.
- Avg daytime high
- 17°C
- warmest season of the year
- Avg overnight low
- 14°C
- Rainfall
- 266 mm
- 40 wet days
- Avg wind
- 18 km/h
- Travel score
- 5.0
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Swansea in Summer
Over the season highs climb from about 15°C in early June to 18°C by late August.
A typical summer day in Swansea reaches about 17°C and drops to 14°C overnight. The warmest of the three months is August, the coolest June.
Swansea weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 8° / 5° | 128 | 17 | 0.4 | 8.1 | 1.1 |
| Feb | 8° / 5° | 90 | 13 | 0.6 | 9.6 | 1.1 |
| Mar | 9° / 6° | 83 | 13.7 | 0.3 | 11.5 | 1.6 |
| Apr | 11° / 7° | 69 | 12 | 0.1 | 13.6 | 2.5 |
| May | 13° / 10° | 72 | 12.4 | 0 | 15.3 | 3.6 |
| Jun | 16° / 12° | 79 | 12.2 | 0 | 16.3 | 4.6 |
| Jul | 18° / 14° | 86 | 13.8 | 0 | 15.9 | 5.2 |
| Aug | 18° / 15° | 101 | 14.3 | 0 | 14.4 | 5.2 |
| Sep | 17° / 13° | 96 | 13.2 | 0 | 12.4 | 4.8 |
| Oct | 14° / 11° | 143 | 16.7 | 0 | 10.4 | 3.4 |
| Nov | 11° / 8° | 143 | 17.3 | 0 | 8.6 | 2.2 |
| Dec | 9° / 6° | 145 | 16.8 | 0.3 | 7.7 | 1.4 |
Cloud cover in Summer
The sky is clear or mostly clear about 20% of the time across summer.
Chance of precipitation in Summer
Swansea gets around 266 mm of rain over 40 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 18 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 16 h 06 min in early June to 13 h 30 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 5.1 kWh/m².
Is summer a good time to visit Swansea?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit Swansea for sightseeing.
What to pack for Swansea in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Swansea sees daytime highs around 17°C and nights near 14°C. Pack rain gear. Worth having: a warm layer and sun protection. About 40 days see rain.
Sea temperature near Swansea in Summer
The nearest coast averages about 16°C across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea offshore is warmest in August at about 18°C and coldest in February near 8°C.
The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 8 | 8 | 8 | 9 | 11 | 14 | 16 | 18 | 17 | 15 | 12 | 10 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Cool | Cool | Cool | Cool | Bracing | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 8 | Bracing |
| Feb | 8 | Bracing |
| Mar | 8 | Bracing |
| Apr | 9 | Bracing |
| May | 11 | Bracing |
| Jun | 14 | Bracing |
| Jul | 16 | Cool |
| Aug | 18 | Cool |
| Sep | 17 | Cool |
| Oct | 15 | Cool |
| Nov | 12 | Bracing |
| Dec | 10 | Bracing |
UV index in Swansea in Summer
Clear-sky midday UV across summer averages around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Swansea peaks around August 13 at about 6 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 6 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 1 | 3 | 4 | 6 | 6 | 6 | 7 | 4 | 2 | 1 | 1 |
| Level | Low | Low | Moderate | Moderate | High | High | High | High | Moderate | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 1 | Low |
| Mar | 3 | Moderate |
| Apr | 4 | Moderate |
| May | 6 | High |
| Jun | 6 | High |
| Jul | 6 | High |
| Aug | 7 | High |
| Sep | 4 | Moderate |
| Oct | 2 | Moderate |
| Nov | 1 | Low |
| Dec | 1 | Low |
Where is Swansea?
Swansea sits at 51.6°N, 3.9°W, 18 m above sea level, in United Kingdom. The nearest listed city is Clydach, 8.0 km away.
Topography around Swansea
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Swansea.
Within 3 km, the terrain around Swansea has only modest variations in elevation — a maximum elevation change of 194 m around an average of 44 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 422 m; within 80 km, large variations in elevation — a maximum elevation change of 878 m.
The land around Swansea is covered by artificial surfaces (34%), water (32%) and trees (23%) within 3 km, water (35%), grassland (28%) and trees (26%) within 16 km, and grassland (46%) and water (35%) within 80 km.
United Kingdom travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type D / G / M
- 230 V · 50 Hz
- Prices
- ≈ 89% of US
- price level, 2025
- GDP per capita
- $57,602
- 2025
- Happiness
- 6.7 / 10
- World Happiness, 2025
- Safe drinking water
- 100%
- of population, 2024
- Homicide rate
- 1.1
- per 100k, 2021
- Road deaths
- 3.2
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Swansea (51.6208°, -3.9432°, elevation 18 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.