The weather in Groix on thursday 18 September 2025
The average max temperature in Groix on 18 September is normally around 21°C. For comparison: the highest daytime temperature in the past 10 years was 24°C in 2014, while the lowest was 17°C in 2017.
There’s a small chance of precipitation, as 4 out of the last 10 years saw some, with an average of 7,9 mm on this day. The wind often comes from the South with a maximum strength of 6 Bft.The UV index can reach 7.
Temperature on 18 September in Groix per year
This chart shows the average temperature on 18 September in Groix, measured in degrees Celsius, over the past years.
Precipitation on 18 September in Groix over the past years
This chart shows the total measured precipitation in millimetres on 18 September in Groix over the past years.
Average Weather in Groix by Month
Click on a month below to see detailed weather info for Groix. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.