Grande-Synthe Temperature by Month
Grande-Synthe, Nord-Pas-de-Calais, France has an average annual maximum temperature of 15°C (59°F), ranging from 8°C (46°F) in January to 23°C (73°F) in August. Below you'll find a full monthly breakdown and a comparison with cities worldwide.
Grande-Synthe Monthly Temperatures
The climate in Grande-Synthe is known for significant temperature differences throughout the year. At night, this contrast is just as clear, with lows ranging from 15°C (59°F) in August to 3°C (37°F) in January.
The chart below illustrates the average maximum day and minimum night temperatures in Grande-Synthe by month:
The coolest part of the day is typically between 4 AM and 6 AM, while 3 PM is usually the warmest, when solar heating is at its peak. August, the city's warmest month, averages 217 hours of sunshine.
The chart below shows the average temperature throughout the year:
Temperature: Grande-Synthe vs France
The map below shows the annual temperature across France. You can also select individual months if you want to compare a specific time of year.
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Grande-Synthe vs World: Temperature Compared
Grande-Synthe's average annual maximum temperature is 15°C (59°F). To put that in context, here's how it compares to a few well-known destinations:
Rome, Italy averages 20°C (68°F) annually, with reliably warm summers and comfortable winters.
Glasgow, Scotland averages 13°C (55°F) a year — mild but often grey, with cold winters and rarely hot summers.
Boston, USA averages 16°C (61°F) annually, with four distinct seasons and cold winters that rival northern Europe.
Brisbane, Australia averages 26°C (79°F) a year, with warm winters and hot, humid summers.
What Does the Temperature Feel Like in Grande-Synthe?
Temperature alone doesn't tell the whole story — humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.
In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.
In Grande-Synthe, January is the coolest month, with average highs of 8°C (46°F) and humidity around 91% — considered very high. For a full picture, see our humidity page.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
Seasonal temperature shifts influence more than just how warm it feels — they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.
Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Grande-Synthe this rarely lasts long on the ground.
For more on Grande-Synthe's weather — including monthly rainfall, sunshine hours, and humidity — visit our Grande-Synthe climate page.
