The climate in Grindavík during September can be summarized as cool and a little damp.
September is in the fall / autumn in Grindavík and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a cool 10°C (49°F), whilst at night 5°C (41°F) is normal.
|Daytime temperature||9.7°C 49.4°F|
|Nightly temperature||5°C 40.9°F|
|Average temperature||7.3°C 45.1°F|
|Daily sunshine||4.1 hrs|
|Avg rainfall||97 mm 3.8 ins|
|Rainy days||18 days|
|Sea temperature||10.9°C 51.5°F|
|Windspeed||20.5kph 13 mph|
On average September is the 6th driest month of the year in Grindavík with around 97mm 3.8 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 18 days, although this may vary considerably.
On the flip side this corresponds to an average of 4.1 hours of sunshine per day.
The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Grindavík in September 2021.
|Hottest month:||July||12.8°C 55°F|
|Driest month:||July||67mm 2.6ins|
|Coldest month:||January||1.7°C 35.1°F|
|Wettest month:||October||124mm 4.9ins|