Saint Helier weather in August

In August, Saint Helier sees average daytime highs of 18°C and overnight lows near 17°C, with 63 mm of rain across 9.8 wet days and about 14.2 hours of daylight. It is the 1st-warmest and 8th-wettest month of the year here.

Day-to-day highs hold fairly steady near 18°C through the month. The sky is clear or mostly clear about 34% of the time in August, and the air most often feels comfortable.

Daylight stretches from about 15 hours at the start of August to 13 h 18 min by month's end. Set against the rest of the year, August is Saint Helier's 2nd-clearest and 12th-windiest month. For the whole year in context, see Saint Helier's year-round climate.

Daytime high
18°
1st warmest
Overnight low
17°
12th coldest
Rainfall
63 mm
9.8 wet days
Daylight
14 h 12 min
5:06 AM – 7:19 PM
Cloud cover
55%
2nd clearest
Wind
21 km/h
12th windiest
Solar energy
5.1 kWh/m²
Travel score
6.1
out of 10

Saint Helier is one of the twelve parishes and capital of Jersey in the Channel Islands.

Density
2,642/km²
people per km²

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 18°C through the month.

A typical August day in Saint Helier reaches about 18°C in the afternoon and slips back to 17°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 17°C and 20°C. Set against its neighbours, August runs on par with July and about 1°C warmer than September.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
11817
21817
31817
41817
51817
61817
71817
81817
91817
101817
111817
121817
131817
141817
151817
161817
171817
181817
191817
201817
211817
221817
231817
241817
251816
261816
271816
281816
291816
301816
311816

Saint Helier weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan / 11015.88.51.5
Feb / 8112.99.81.4
Mar / 6912.411.61.9
Apr11° / 5710.513.42.7
May13° / 11°539.4153.8
Jun16° / 14°508.715.95.0
Jul18° / 16°489.115.66.0
Aug18° / 17°639.814.26.1
Sep17° / 16°771112.45.5
Oct15° / 13°12215.510.54.0
Nov12° / 10°13217.68.92.7
Dec10° / 13816.78.11.9

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 34% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 21% of August, with mostly cloudy or overcast conditions the remaining 45%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15644
25644
35644
45644
55644
65644
75644
85743
95644
105743
115743
125743
135743
145743
155644
165743
175545
185545
195545
205446
215446
225446
235347
245347
255347
265347
275347
285347
295347
305347
315446

Chance of precipitation in August

Any precipitation

Saint Helier gets around 63 mm of rain over 9.8 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 32% and peaks near 34% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
129
229
329
429
530
630
730
831
931
1031
1131
1232
1332
1432
1532
1633
1733
1834
1934
2034
2134
2234
2333
2433
2532
2632
2731
2831
2931
3031
3131

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

Most of August feels comfortable — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, August lands in the comfortable band about 52% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
11357300
21456300
31455301
41455301
51553311
61554301
71554301
81653301
91653301
101653301
111753291
121753291
131754281
141853281
151853281
161854271
171854271
181953271
192053261
202152261
212252251
222352250
232452240
242651230
252751220
262950220
273049210
283148200
293347200
303447190
313646180

Wind in August

Winds average 21 km/h in August, the calmest month.

Across August, daily wind ranges from about 20 km/h on the calmest days to 22 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202531
Wind speed (km/h)Feels
120light breeze
220light breeze
320light breeze
420light breeze
520light breeze
620light breeze
720light breeze
820breezy
920breezy
1020breezy
1120breezy
1220breezy
1321breezy
1421breezy
1521breezy
1621breezy
1721breezy
1821breezy
1921breezy
2021breezy
2121breezy
2221breezy
2322breezy
2422breezy
2522breezy
2622breezy
2722breezy
2822breezy
2922breezy
3022breezy
3122breezy

Sunrise & sunset in August

DaylightNight

Daylight runs from about 15 hours at the start of August to 13 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 102 minutes over August. Sunrise moves from 4:45 AM to 5:28 AM, and sunset from 7:44 PM to 6:49 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
115.04:457:44
214.94:467:43
314.94:487:41
414.84:497:40
514.84:507:38
614.74:527:36
714.74:537:35
814.64:557:33
914.64:567:31
1014.54:577:30
1114.54:597:28
1214.45:007:26
1314.45:027:24
1414.35:037:23
1514.35:057:21
1614.25:067:19
1714.25:087:17
1814.15:097:15
1914.05:117:13
2014.05:127:11
2113.95:137:09
2213.95:157:07
2313.85:167:05
2413.85:187:03
2513.75:197:01
2613.65:216:59
2713.65:226:57
2813.55:246:55
2913.55:256:53
3013.45:276:51
3113.35:286:49

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.1 kWh/m².

For context, solar energy here swings from a low near 0.83 kWh/m² to a high of 6.27 kWh/m² in June across the year — August's 5.1 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.7Bright
25.7Bright
35.6Bright
45.6Bright
55.6Bright
65.5Bright
75.5Bright
85.4Bright
95.4Bright
105.3Bright
115.3Bright
125.3Bright
135.2Bright
145.2Bright
155.1Bright
165.1Bright
175.0Bright
185.0Bright
195.0Bright
204.9Bright
214.9Bright
224.8Bright
234.8Bright
244.8Bright
254.7Bright
264.7Bright
274.7Bright
284.6Bright
294.6Bright
304.6Bright
314.5Bright
Planning a trip in August

Hazard calendar for Saint Helier

In seasonPeak

In August, Saint Helier sits inside 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.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is August a good time to visit Saint Helier?

Our two travel scores rate August for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

6.1
Sightseeing
1st-best month of the year
2.2
Beach & pool
1st-best month of the year

August is a reasonable time to visit Saint Helier for sightseeing.

What to pack for Saint Helier in August

From August's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In August, Saint Helier sees daytime highs around 18°C and nights near 17°C. Worth packing: rain gear, sun protection and a windbreaker. About 10 days see rain.

rain gearsun protectiona windbreaker

Sea temperature near Saint Helier in August

The nearest coast averages about 18°C in August — 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.

10°15°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°C)Comfort
Jan10Bracing
Feb9Bracing
Mar9Bracing
Apr10Bracing
May12Bracing
Jun15Bracing
Jul17Cool
Aug18Cool
Sep18Cool
Oct16Cool
Nov14Bracing
Dec11Bracing

UV index in Saint Helier in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 7 — 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowAug 13UV 7Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr5Moderate
May6High
Jun7High
Jul6High
Aug7High
Sep5Moderate
Oct3Moderate
Nov1Low
Dec1Low
Location & terrain

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.

3 km
100 m
16 km
137 m
80 km
290 m
treesgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Saint Peter Port 43 km · Octeville 59 km · Saint-Malo 61 km · Équeurdreville-Hainneville 61 km · Cherbourg 61 km · Tourlaville 63 km · Saint-Lô 74 km · Saint-Brieuc 89 km

Jersey travel facts

Power plugs
Type G
230 V · 50 Hz
Religion
Christian 85%agnostic 13%atheist 1%Baha'i 0%

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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).