Saint Helier in Summer
In summer (June, July and August), Saint Helier sees average daytime highs around 17°C and overnight lows near 15°C, with 161 mm of rain over about 28 wet days across the season. It is the warmest season of the year and the driest season of the year.
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 35% of the time across summer, and the air most often feels comfortable.
Summer is Saint Helier's best season of the year to visit on our travel score. For the whole year in context, see Saint Helier's year-round climate.
- Avg daytime high
- 17°C
- warmest season of the year
- Avg overnight low
- 15°C
- Rainfall
- 161 mm
- 28 wet days
- Avg wind
- 21 km/h
- Travel score
- 5.7
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Saint Helier 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 Saint Helier reaches about 17°C and drops to 15°C overnight. The warmest of the three months is August, the coolest June.
Saint Helier 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 | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 9° / 7° | 110 | 15.8 | 8.5 | 1.5 |
| Feb | 9° / 7° | 81 | 12.9 | 9.8 | 1.4 |
| Mar | 9° / 8° | 69 | 12.4 | 11.6 | 1.9 |
| Apr | 11° / 9° | 57 | 10.5 | 13.4 | 2.7 |
| May | 13° / 11° | 53 | 9.4 | 15 | 3.8 |
| Jun | 16° / 14° | 50 | 8.7 | 15.9 | 5.0 |
| Jul | 18° / 16° | 48 | 9.1 | 15.6 | 6.0 |
| Aug | 18° / 17° | 63 | 9.8 | 14.2 | 6.1 |
| Sep | 17° / 16° | 77 | 11 | 12.4 | 5.5 |
| Oct | 15° / 13° | 122 | 15.5 | 10.5 | 4.0 |
| Nov | 12° / 10° | 132 | 17.6 | 8.9 | 2.7 |
| Dec | 10° / 8° | 138 | 16.7 | 8.1 | 1.9 |
Cloud cover in Summer
The sky is clear or mostly clear about 35% of the time across summer.
Chance of precipitation in Summer
Saint Helier gets around 161 mm of rain over 28 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels comfortable — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 21 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 15 h 42 min in early June to 13 h 18 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 5.8 kWh/m².
Hazard calendar for Saint Helier
In summer, Saint Helier overlaps its rainy season season. The full year is below, with each hazard's peak months called out.
Saint Helier's rainy season runs August–March, when most of the year's rain falls.
Is summer a good time to visit Saint Helier?
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 Saint Helier for sightseeing.
What to pack for Saint Helier in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Saint Helier sees daytime highs around 17°C and nights near 15°C. Pack sun protection. Worth having: a warm layer, rain gear and a windbreaker. About 28 days see rain.
Sea temperature near Saint Helier 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 9°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) | 10 | 9 | 9 | 10 | 12 | 15 | 17 | 18 | 18 | 16 | 14 | 11 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Cool | Cool | Cool | Cool | Bracing | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 10 | Bracing |
| Feb | 9 | Bracing |
| Mar | 9 | Bracing |
| Apr | 10 | Bracing |
| May | 12 | Bracing |
| Jun | 15 | Bracing |
| Jul | 17 | Cool |
| Aug | 18 | Cool |
| Sep | 18 | Cool |
| Oct | 16 | Cool |
| Nov | 14 | Bracing |
| Dec | 11 | Bracing |
UV index in Saint Helier 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 Saint Helier peaks around August 13 at about 7 (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 | 2 | 3 | 5 | 6 | 7 | 6 | 7 | 5 | 3 | 1 | 1 |
| Level | Low | Low | Moderate | Moderate | High | High | High | High | Moderate | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 2 | Low |
| Mar | 3 | Moderate |
| Apr | 5 | Moderate |
| May | 6 | High |
| Jun | 7 | High |
| Jul | 6 | High |
| Aug | 7 | High |
| Sep | 5 | Moderate |
| Oct | 3 | Moderate |
| Nov | 1 | Low |
| Dec | 1 | Low |
Where is Saint Helier?
Saint Helier sits at 49.2°N, 2.1°W, 11 m above sea level, in Jersey. The nearest listed city is Saint Peter Port, 43 km away.
Topography around Saint Helier
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Saint Helier.
Within 3 km, the terrain around Saint Helier has only modest variations in elevation — a maximum elevation change of 100 m around an average of 31 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 137 m; within 80 km, significant variations in elevation — a maximum elevation change of 290 m.
The land around Saint Helier is covered by water (32%), trees (22%) and artificial surfaces (21%) within 3 km, water (85%) within 16 km, and water (68%) within 80 km.
Jersey travel facts
- Power plugs
- Type G
- 230 V · 50 Hz
- 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 Saint Helier (49.188°, -2.1049°, elevation 11 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.