Calais, where it's located

The climate of Calais is generally cool and wet, rainy and windy all year round, but especially in autumn and winter.
The city is located in the north-east of France, on the coast, at the point (called Strait of Dover or Pas de Calais) where the distance from England is shortest.
The average temperature of the coldest month (January) is of 4.9 °C (41 °F), that of the warmest month (August) is of 17.9 °C (64 °F). Here are the average temperatures.
Calais - Average temperatures
Min (°C)2345811131411862
Max (°C)781013161922221915117
Min (°F)363739414652555752464336
Max (°F)454650556166727266595245

Precipitation amounts to 725 millimeters (28.5 inches) per year: so, it is at an intermediate level. It ranges from 40 mm (1.6 in) in the driest months (March, April) to 90 mm (3.5 in) in the wettest (November). Here is the average precipitation.
Calais - Average precipitation

The sea temperature ranges between 7 °C (45 °F) and 18 °C (64 °F). So, it never becomes warm for swimming. Here are the average sea temperatures.
Calais - Sea temperature
Temp (°C)87791114161817151210
Temp (°F)464545485257616463595450


Best Time

The best time to visit Calais runs from mid-May to mid-September, since it is the warmest and sunniest period of the year. Sometimes, nights can be cool or even a little cold even in these months, so it can be useful to bring a sweatshirt or sweater and a light jacket for the evening.