Grande-Synthe weather in October

In October, Grande-Synthe sees average daytime highs of 15°C and overnight lows near 10°C, with 65 mm of rain across 11.9 wet days and about 10.4 hours of daylight. It is the 6th-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 17°C in the first days to 13°C by the end. The sky is clear or mostly clear about 16% of the time in October, and the air most often feels dry.

Daylight stretches from about 11 h 24 min at the start of October to 9 h 30 min by month's end. Set against the rest of the year, October is Grande-Synthe's 8th-clearest and 6th-windiest month. For the whole year in context, see Grande-Synthe's year-round climate.

Daytime high
15°
6th warmest
Overnight low
10°
7th coldest
Rainfall
65 mm
11.9 wet days
Daylight
10 h 24 min
7:24 AM – 5:48 PM
Cloud cover
70%
8th clearest
Wind
17 km/h
6th windiest
Solar energy
1.93 kWh/m²
Travel score
4.2
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 October

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 17°C in the first days to 13°C by the end.

A typical October day in Grande-Synthe reaches about 15°C in the afternoon and slips back to 10°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 11°C and 19°C. Set against its neighbours, October runs about 4°C cooler than September and about 4°C warmer than November.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
11711
21711
31711
41711
51611
61611
71611
81610
91610
101610
111610
121610
131510
141510
151510
161510
17159
18159
19159
20159
21149
22149
23149
24149
25149
26149
27149
28139
29138
30138
31138

How October really feels in Grande-Synthe

Once humidity and wind are folded in, October 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

October 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 October compares with the rest of the year at a glance. October is the 6th-warmest and 3rd-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 October

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 16% of the time in October.

Beyond those clear spells, partly cloudy skies cover about 15% of October, with mostly cloudy or overcast conditions the remaining 69%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13268
23268
33169
42971
53070
62971
73070
83070
92971
102971
113169
123169
133268
143268
153268
163367
173367
183268
193367
203367
213367
223367
233367
243367
253169
263169
273169
283169
293169
303169
312971

Chance of precipitation in October

Any precipitation

Grande-Synthe gets around 65 mm of rain over 11.9 wet days in October. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 39% and peaks near 41% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
139
239
339
438
538
638
738
838
937
1037
1137
1238
1338
1438
1538
1638
1739
1839
1939
2039
2139
2240
2340
2440
2540
2640
2740
2840
2940
3040
3141

Humidity in October

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, October lands in the dry band about 86% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
174251
275241
376231
477221
578211
679201
780191
881181
981181
1082171
1183161
1283161
1384151
1485141
1586140
1686140
1787130
1888120
1988120
2089110
2189110
2290100
239190
249190
259280
269280
279370
289370
299460
309460
319550

Wind in October

Winds average 17 km/h in October.

Across October, daily wind ranges from about 16 km/h on the calmest days to 18 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
116light breeze
216light breeze
316light breeze
416light breeze
516light breeze
616light breeze
716light breeze
816light breeze
916light breeze
1016light breeze
1116light breeze
1216light breeze
1316light breeze
1416light breeze
1516light breeze
1617light breeze
1717light breeze
1817light breeze
1917light breeze
2017light breeze
2117light breeze
2217light breeze
2317light breeze
2417light breeze
2518light breeze
2618light breeze
2718light breeze
2818light breeze
2918light breeze
3018light breeze
3118light breeze

Sunrise & sunset in October

DaylightNight

Daylight runs from about 11 h 24 min at the start of October to 9 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 114 minutes over October. Sunrise moves from 6:58 AM to 7:50 AM, and sunset from 6:21 PM to 5:19 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.46:586:21
211.37:006:19
311.37:026:17
411.27:036:14
511.17:056:12
611.17:076:10
711.07:086:08
810.97:106:05
910.97:126:03
1010.87:136:01
1110.77:155:59
1210.77:175:57
1310.67:185:54
1410.57:205:52
1510.57:225:50
1610.47:245:48
1710.37:255:46
1810.37:275:44
1910.27:295:42
2010.27:315:40
2110.17:325:38
2210.07:345:36
2310.07:365:34
249.97:375:32
259.87:395:30
269.87:415:28
279.77:435:26
289.77:455:24
299.67:465:22
309.57:485:21
319.57:505:19

Solar energy in October

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in October, about 1.93 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 — October's 1.93 kWh/m² falls in the middle.

0123151015202531
Solar energy (kWh/m²)Level
12.5Moderate
22.5Moderate
32.4Moderate
42.4Moderate
52.3Moderate
62.3Moderate
72.3Moderate
82.2Moderate
92.2Moderate
102.2Moderate
112.1Moderate
122.1Moderate
132.1Moderate
142.0Moderate
152.0Dim
161.9Dim
171.9Dim
181.9Dim
191.8Dim
201.8Dim
211.8Dim
221.7Dim
231.7Dim
241.7Dim
251.6Dim
261.6Dim
271.6Dim
281.5Dim
291.5Dim
301.4Dim
311.4Dim
Planning a trip in October

Is October a good time to visit Grande-Synthe?

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

4.2
Sightseeing
6th-best month of the year
0.3
Beach & pool
6th-best month of the year

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

What to pack for Grande-Synthe in October

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

In October, Grande-Synthe sees daytime highs around 15°C and nights near 10°C. Worth packing: a warm layer and rain gear. About 12 days see rain.

a warm layerrain gear

Sea temperature near Grande-Synthe in October

The nearest coast averages about 15°C in October — 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 October

LowModerateHighVery highExtreme

Clear-sky midday UV in October peaks around 2. 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
October 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).