The mean temperature in Santander, Cantabria is somewhat warm at 18.6 °C (65.48 °F).
Afternoons can be warm with average high temperatures reaching 21 °C (69.8 °F).
Overnight temperatures are generally mild with an average low of 15 °C (59 °F).
The mean diurnal temperature variation/ range in September is 6 °C (10.8 °F).
The weather in September is hardly arid with rain every now and then. Circa 92.6mm (3.6in) of liquid tumbles across an average of 14 days.
In September the blue above Santander, Cantabria is slightly fair with an average of a mediocre 5:01 of dazzling solar radiation per day.
The shortest day is 11:42 long and the longest day is 13:10 long with an average length of 12:27.
There are approximately 7:14 per day when bright sunshine is absent due to cloud, haze or the sun being too low on the horizon to register.
It is sunny approximately 41% of daylight hours and cloudy 59% of daylight hours.