Alderney
Guernsey
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Alderney, Guernsey

Sea temperature

The month with the warmest seawater in Alderney, Guernsey, is Septiembre, with an average sea temperature of 17.4°C (63.3°F).
Note: Swimming in 17.4°C (63.3°F) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 21°C (69.8°F).

Daylight

In Alderney, Guernsey, the average length of the day in Septiembre is 12.6h.

What is the month with the warmest sea water in Alderney?

The month with the warmest seawater is Septiembre, with an average sea temperature of 17.4°C (63.3°F).

How cold is the water in Septiembre in Alderney?

In Septiembre, the average sea temperature in Alderney, Guernsey, is 17.4°C (63.3°F). For swimming, a surface water temperature of 17.4°C (63.3°F) is not enjoyable for the majority. It is not considered safe, as controlling breathing becomes progressively more difficult as water temperature decreases below 21°C (69.8°F).

What is the average length of the day in Septiembre in Alderney?

In Alderney, the average length of the day in Septiembre is 12.6h.
Average sea temperature in September - Alderney, Guernsey
  • Average sea temperature in September: 17.4°C

The best month for swimming (with the highest average sea temperature) is September (17.4°C).
The coldest month (with the lowest average sea temperature) is March (9.3°C).

Average daylight in September - Alderney, Guernsey
  • Average daylight in September: 12.6h

The month with the longest days is June (Average daylight: 16.2h).
The month with shortest days is December (Average daylight: 8.2h).