Sunbury-on-Thames in Summer
In summer (June, July and August), Sunbury-on-Thames sees average daytime highs around 21°C and overnight lows near 13°C, with 168 mm of rain over about 31 wet days across the season. It is the warmest season of the year and the 2nd-wettest season.
Across summer, daytime highs hold fairly steady around 21°C. The sky is clear or mostly clear about 15% of the time across summer, and the air most often feels dry.
Summer is Sunbury-on-Thames's best season of the year to visit on our travel score. For the whole year in context, see Sunbury-on-Thames's year-round climate.
- Avg daytime high
- 21°C
- warmest season of the year
- Avg overnight low
- 13°C
- Rainfall
- 168 mm
- 31 wet days
- Avg wind
- 13 km/h
- Travel score
- 6.2
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Sunbury-on-Thames in Summer
Across summer, daytime highs hold fairly steady around 21°C.
A typical summer day in Sunbury-on-Thames reaches about 21°C and drops to 13°C overnight. The warmest of the three months is July, the coolest June.
How summer really feels in Sunbury-on-Thames
Once humidity and wind are folded in, summer brings about 0 days that feel above 32°C and 0 that feel at or below 0°C.
summer sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Sunbury-on-Thames 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 | 7° / 3° | 55 | 10.9 | 0.9 | 8.1 | 1.0 |
| Feb | 8° / 3° | 44 | 9.1 | 1.1 | 9.6 | 1.2 |
| Mar | 10° / 4° | 43 | 10.1 | 0.6 | 11.5 | 2.3 |
| Apr | 13° / 6° | 49 | 11.2 | 0.2 | 13.5 | 3.5 |
| May | 16° / 8° | 52 | 9.8 | 0 | 15.3 | 5.0 |
| Jun | 19° / 11° | 55 | 9.9 | 0 | 16.3 | 5.9 |
| Jul | 22° / 13° | 53 | 10.6 | 0 | 15.9 | 6.4 |
| Aug | 21° / 13° | 60 | 10.3 | 0 | 14.4 | 6.3 |
| Sep | 18° / 11° | 48 | 8.9 | 0 | 12.4 | 5.8 |
| Oct | 14° / 8° | 60 | 11.2 | 0 | 10.4 | 4.0 |
| Nov | 10° / 5° | 64 | 11 | 0.1 | 8.6 | 2.3 |
| Dec | 8° / 3° | 58 | 11 | 0.8 | 7.7 | 1.2 |
Cloud cover in Summer
The sky is clear or mostly clear about 15% of the time across summer.
Chance of precipitation in Summer
Sunbury-on-Thames gets around 168 mm of rain over 31 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 13 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 16 hours 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 4.8 kWh/m².
Is summer a good time to visit Sunbury-on-Thames?
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 Sunbury-on-Thames for sightseeing.
What to pack for Sunbury-on-Thames in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Sunbury-on-Thames sees daytime highs around 21°C and nights near 13°C. Worth packing: rain gear and sun protection. About 31 days see rain.
UV index in Sunbury-on-Thames 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 Sunbury-on-Thames peaks around August 10 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 | 3 | 6 | 6 | 6 | 6 | 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 | 3 | Moderate |
| May | 6 | High |
| Jun | 6 | High |
| Jul | 6 | High |
| Aug | 6 | High |
| Sep | 4 | Moderate |
| Oct | 2 | Moderate |
| Nov | 1 | Low |
| Dec | 1 | Low |
Where is Sunbury-on-Thames?
Sunbury-on-Thames sits at 51.4°N, 0.4°W, 12 m above sea level, in United Kingdom. The nearest listed city is Walton-on-Thames, 2.0 km away.
Topography around Sunbury-on-Thames
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Sunbury-on-Thames.
Within 3 km, the terrain around Sunbury-on-Thames has only modest variations in elevation — a maximum elevation change of 28 m around an average of 14 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 175 m; within 80 km, significant variations in elevation — a maximum elevation change of 301 m.
The land around Sunbury-on-Thames is covered by grassland (29%), artificial surfaces (29%) and trees (27%) within 3 km, trees (40%), grassland (27%) and artificial surfaces (27%) within 16 km, and grassland (31%), trees (27%) and cropland (26%) 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 Sunbury-on-Thames (51.4042°, -0.4182°, elevation 12 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.