Grande-Synthe weather in July

In July, Grande-Synthe sees average daytime highs of 22°C and overnight lows near 15°C, with 54 mm of rain across 10.5 wet days and about 15.8 hours of daylight. It is the 2nd-warmest and 9th-wettest month of the year here.

Highs climb over the month, from about 21°C in the first days to 22°C by the end. The sky is clear or mostly clear about 25% of the time in July, and the air most often feels comfortable.

Daylight stretches from about 16 h 18 min at the start of July to 15 h 18 min by month's end. Set against the rest of the year, July is Grande-Synthe's 1st-clearest and 11th-windiest month. For the whole year in context, see Grande-Synthe's year-round climate.

Daytime high
22°
2nd warmest
Overnight low
15°
11th coldest
Rainfall
54 mm
10.5 wet days
Daylight
15 h 54 min
5:00 AM – 8:53 PM
Cloud cover
61%
1st clearest
Wind
15 km/h
11th windiest
Solar energy
5.51 kWh/m²
Travel score
6.5
out of 10
Air quality
Good
PM10 23.4 µg/m³ · 2019

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

Temperature in July

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 21°C in the first days to 22°C by the end.

A typical July day in Grande-Synthe reaches about 22°C in the afternoon and slips back to 15°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 26°C. Set against its neighbours, July runs about 2°C warmer than June and on par with August.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12114
22114
32114
42114
52114
62114
72114
82114
92114
102114
112114
122114
132114
142114
152115
162115
172215
182215
192215
202215
212215
222215
232215
242215
252215
262215
272215
282315
292315
302315
312315

How July really feels in Grande-Synthe

Once humidity and wind are folded in, July averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

July sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Grande-Synthe weather by month

How July compares with the rest of the year at a glance. July is the 2nd-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 5611.80.98.20.9
Feb / 47100.89.61.1
Mar10° / 4610.60.511.52.3
Apr13° / 4410.20.113.53.7
May16° / 10°5410.7015.35.1
Jun19° / 12°549.9016.26.0
Jul22° / 15°5410.5015.86.5
Aug22° / 15°6310.5014.36.5
Sep19° / 13°559.8012.45.9
Oct15° / 10°6511.9010.44.2
Nov11° / 6512.80.38.72.3
Dec / 6812.50.87.81.1

Cloud cover in July

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% of the time in July, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 21% of July, with mostly cloudy or overcast conditions the remaining 54%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14456
24357
34357
44357
54357
64258
74258
84357
94357
104357
114456
124357
134456
144555
154555
164654
174852
184852
194951
204951
214852
224951
234951
244951
254951
264951
275050
285050
294951
304951
314852

Chance of precipitation in July

Any precipitation

Grande-Synthe gets around 54 mm of rain over 10.5 wet days in July. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 33% and peaks near 36% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
134
234
335
435
536
636
736
836
936
1036
1135
1235
1334
1434
1533
1633
1732
1832
1932
2032
2131
2231
2331
2431
2531
2631
2731
2831
2931
3032
3132

Humidity in July

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, July lands in the comfortable band about 50% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1514180
2494280
3484480
4464581
5454691
6444691
7434791
84248101
94148101
104049101
114049111
123949111
133850121
143750121
153650131
163550141
173451141
183351151
193251161
203152161
213052171
223052171
232952181
242853181
252853181
262754181
272654182
282654182
292554192
302554192
312455192

Wind in July

Winds average 15 km/h in July.

Across July, daily wind ranges from about 14 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
115light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1015light breeze
1115light breeze
1215light breeze
1315light breeze
1415light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light breeze
3114light breeze

Sunrise & sunset in July

DaylightNight

Daylight runs from about 16 h 18 min at the start of July to 15 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 60 minutes over July. Sunrise moves from 4:46 AM to 5:19 AM, and sunset from 9:02 PM to 8:34 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
116.34:469:02
216.24:479:02
316.24:489:01
416.24:489:01
516.24:499:01
616.24:509:00
716.24:519:00
816.14:518:59
916.14:528:59
1016.14:538:58
1116.14:548:57
1216.04:558:57
1316.04:568:56
1416.04:578:55
1515.94:588:54
1615.95:008:53
1715.95:018:52
1815.85:028:51
1915.85:038:50
2015.75:048:49
2115.75:068:48
2215.75:078:47
2315.65:088:46
2415.65:108:44
2515.55:118:43
2615.55:128:42
2715.45:148:40
2815.45:158:39
2915.35:168:37
3015.35:188:36
3115.35:198:34

Solar energy in July

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in July, about 5.51 kWh/m².

For context, solar energy here swings from a low near 0.66 kWh/m² to a high of 5.63 kWh/m² in June across the year — July's 5.51 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.7Bright
25.7Bright
35.7Bright
45.7Bright
55.6Bright
65.6Bright
75.6Bright
85.6Bright
95.6Bright
105.5Bright
115.5Bright
125.5Bright
135.5Bright
145.5Bright
155.5Bright
165.5Bright
175.5Bright
185.5Bright
195.5Bright
205.5Bright
215.5Bright
225.5Bright
235.5Bright
245.5Bright
255.4Bright
265.4Bright
275.4Bright
285.4Bright
295.4Bright
305.3Bright
315.3Bright
Planning a trip in July

Is July a good time to visit Grande-Synthe?

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

6.5
Sightseeing
1st-best month of the year
4.3
Beach & pool
2nd-best month of the year

July is a reasonable time to visit Grande-Synthe for sightseeing.

What to pack for Grande-Synthe in July

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

In July, Grande-Synthe sees daytime highs around 22°C and nights near 15°C. Worth packing: rain gear and sun protection. About 11 days see rain.

rain gearsun protection

Sea temperature near Grande-Synthe in July

The nearest coast averages about 17°C in July — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 13 km away) is warmest in August at about 18°C and coldest in February near 7°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

5°10°15°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°C)Comfort
Jan8Bracing
Feb7Bracing
Mar7Bracing
Apr9Bracing
May12Bracing
Jun15Bracing
Jul17Cool
Aug18Cool
Sep18Cool
Oct15Cool
Nov13Bracing
Dec10Bracing

UV index in Grande-Synthe in July

LowModerateHighVery highExtreme

Clear-sky midday UV in July peaks 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 Grande-Synthe peaks around June 22 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJun 22UV 6Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar3Moderate
Apr4Moderate
May6High
Jun6High
Jul6High
Aug6High
Sep4Moderate
Oct2Moderate
Nov1Low
Dec1Low
Location & terrain

Where is Grande-Synthe?

Grande-Synthe sits at 51.0°N, 2.3°E, 2 m above sea level, in France. The nearest listed city is Saint-Pol-sur-Mer, 3.0 km away.

Topography around Grande-Synthe

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Grande-Synthe.

Within 3 km, the terrain around Grande-Synthe has only modest variations in elevation — a maximum elevation change of 42 m around an average of 5 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 52 m; within 80 km, significant variations in elevation — a maximum elevation change of 290 m.

The land around Grande-Synthe is covered by artificial surfaces (50%) and trees (22%) within 3 km, water (39%) and cropland (37%) within 16 km, and water (38%) and cropland (34%) within 80 km.

3 km
42 m
16 km
52 m
80 km
290 m
treesgrasslandcroplandartificial surfacesbare terrainwater
July weather nearby: Saint-Pol-sur-Mer 3.0 km · Dunkirk 6.0 km · Coudekerque-Branche 7.0 km · Koksijde 26 km · Saint-Omer 30 km · Calais 32 km · Poperinge 35 km · Hazebrouck 36 km

France travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / E
230 V · 50 Hz
Prices
≈ 77% of US
price level, 2025
GDP per capita
$48,986
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.3
per 100k, 2023
Road deaths
5.1
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 539
Religion
Roman Catholic 47%none 33%Muslim 4%Protestant 2%

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 Grande-Synthe (51.0154°, 2.2997°, elevation 2 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).