Annual mean 12°C · wettest around November · prevailing wind W
Warmest
21.8 °C
Coldest
6.0 °C
Wettest
31%
Windiest
7.2 m/s
Prevailing
W
5.9 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
never good
never good
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Every reading
bars actual · line feels-like, °Cchance of rain, %wind speed, m/ssky covered, %
The average temperature in Grande-Synthe over the whole year is 12°C. August is the hottest month, with highs of about 21°C; January is the coldest, with lows of about 5°C. Grande-Synthe has no sharply defined rainy season: the chance of rain on a given day runs from 14% in April, the driest month, to 28% in November, the wettest. Winds in Grande-Synthe are highest in February, averaging 5.9 m/s (21 km/h), and lightest in July, at 4.5 m/s (16 km/h). The prevailing wind is from the W. The clearest skies in Grande-Synthe come in August, when the sky is typically 72% covered; December is the cloudiest month, at 86%.
Month by month Grande-Synthe climate by month: average temperatures year round · click a month to read it
Month
High
Low
Feels like
Chance of rain
Cloud
Wind
Being outside
Sun
Walking
January
7°C
5°C
1°C
20%
84%
5.6 m/s
0
0
10
February
8°C
5°C
2°C
19%
80%
5.9 m/s
0
0
19
March
10°C
6°C
4°C
18%
79%
5.5 m/s
2
0
31
April
12°C
8°C
7°C
14%
75%
4.8 m/s
8
0
52
May
16°C
11°C
12°C
15%
75%
4.7 m/s
26
1
76
June
19°C
14°C
16°C
16%
75%
4.6 m/s
58
6
79
July
21°C
16°C
18°C
14%
75%
4.5 m/s
76
8
79
August
21°C
17°C
19°C
18%
72%
4.5 m/s
78
10
74
September
19°C
14°C
16°C
21%
75%
4.5 m/s
60
6
77
October
15°C
11°C
12°C
27%
80%
4.8 m/s
24
0
76
November
10°C
8°C
5°C
28%
84%
5.2 m/s
0
0
40
December
8°C
6°C
2°C
24%
86%
5.6 m/s
0
0
19
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Grande-Synthe weather by season
Year round, Grande-Synthe has days of about 7°C at their warmest in January, its coolest month, and 21°C in August, its warmest; the coolest hours of the day run from 5°C to 17°C through the year, and the average temperature over the year is 12°C around the clock. Rain is most likely around November and least likely around April. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Grande-Synthe weather in winterDecember to February
High 7°CLow 5°CRain 21%
Winter in Grande-Synthe has typical daily highs of about 7°C and lows of about 5°C, with a 21% chance of rain on a given day.
Grande-Synthe weather in springMarch to May
High 13°CLow 8°CRain 16%
Spring in Grande-Synthe has typical daily highs of about 13°C and lows of about 8°C, with a 16% chance of rain on a given day.
Grande-Synthe weather in summerJune to August
High 20°CLow 16°CRain 16%
Summer in Grande-Synthe has typical daily highs of about 20°C and lows of about 16°C, with a 16% chance of rain on a given day.
Grande-Synthe weather in autumnSeptember to November
High 15°CLow 11°CRain 25%
Autumn in Grande-Synthe has typical daily highs of about 15°C and lows of about 11°C, with a 25% chance of rain on a given day.
When is the rainy season in Grande-Synthe?
Grande-Synthe has no sharply defined rainy season: the chance of rain on a given day runs from 14% in April, the driest month, to 28% in November, the wettest.
What time of year is Grande-Synthe windiest?
Winds in Grande-Synthe are highest in February, averaging 5.9 m/s (21 km/h), and lightest in July, at 4.5 m/s (16 km/h). The prevailing wind is from the W.
What is the average temperature in Grande-Synthe year round?
The average temperature in Grande-Synthe over the whole year is 12°C. August is the hottest month, with highs of about 21°C; January is the coldest, with lows of about 5°C.