September weather forecastGrindavik, Iceland
September
Weather in September
September sees a slight cool down in Grindavik's weather, yet the temperatures are still comfortably mild. The gradual decline in temperatures provides an ideal backdrop for enjoying outdoor activities, be it hiking along scenic coastal trails or visiting the local museums. Despite the lower temperatures, the scenery becomes more vivid due to the blossoming heath and beard grass painting the landscape in hues of yellow, red and orange. Whether it's exploring the unique Icelandic flora or cuddling up indoors, September in Grindavik offers something for every visitor. Autumn's arrival does not dampen the spirit of the city but rather enhances it with a vibrant splash of colors.Temperature
September's advent in Grindavik presents an average high-temperature of a still cool 10.3°C (50.5°F), indicating a slight variation from the conditions of the previous month. Grindavik's nocturnal readings in September exhibit minimal variation from the daytime temperatures, averaging at a chilly 8.4°C (47.1°F).Humidity
The average relative humidity in September in Grindavik is 79%.Rainfall
In Grindavik, in September, during 19.9 rainfall days, 86mm (3.39") of precipitation is typically accumulated. Throughout the year, there are 193.9 rainfall days, and 833mm (32.8") of precipitation is accumulated.Snowfall
June through September are months without snowfall in Grindavik.Sea temperature
In September, the average sea temperature in Grindavik is 10.1°C (50.2°F).Note: Dipping into 10.1°C (50.2°F) below 10°C (50°F) is possible with the right protection; absent that, anticipate cold shock and hampered breathing. Swimming momentarily at 13°C (55.4°F) can be jarring.
Daylight
The average length of the day in September in Grindavik is 13h and 0min.On the first day of September, sunrise is at 06:15 and sunset at 20:43. On the last day of the month, sunrise is at 07:37 and sunset at 19:01 GMT.
Sunshine
In September, the average sunshine in Grindavik, Iceland, is 4.8h.UV index
The average daily maximum UV index in September in Grindavik is 3. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: The UV index of 3 in September translates into these instructions:
Prioritize safety - Suggestions to prevent sun damage are offered. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Grindavik, Iceland
- Average high temperature in September: 10.3°C
The warmest months (with the highest average high temperature) are July and August (12.2°C).
The months with the lowest average high temperature are February, March and December (4.2°C).
- Average low temperature in September: 8.4°C
The month with the highest average low temperature is July (9.9°C).
The coldest months (with the lowest average low temperature) are March and December (1.3°C).
Average pressure in September
Grindavik, Iceland
- Average pressure in September: 1002.6mbar
The month with the highest atmospheric pressure is June (1013.7mbar).
The month with the lowest atmospheric pressure is January (996.1mbar).
Average wind speed in September
Grindavik, Iceland
- Average wind speed in September: 27.9km/h
The windiest month (with the highest average wind speed) is February (35km/h).
The calmest month (with the lowest average wind speed) is June (20.1km/h).
Average humidity in September
Grindavik, Iceland
- Average humidity in September: 79%
The months with the highest relative humidity are July and August (81%).
The month with the lowest relative humidity is December (74%).
Average rainfall in September
Grindavik, Iceland
- Average rainfall in September: 86mm
The wettest month (with the highest rainfall) is January (99mm).
The driest month (with the least rainfall) is June (35mm).
Average rainfall days in September
Grindavik, Iceland
- Average rainfall days in September: 19.9 days
The month with the highest number of rainy days is September (19.9 days).
The month with the least rainy days is June (12.5 days).
Average snowfall in September
Grindavik, Iceland
- Average snowfall in September: 0mm
The month with the highest snowfall is March (75mm).
The months with the least snowfall are June, July, August and September (0mm).
Average snowfall days in September
Grindavik, Iceland
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is March (8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in September
Grindavik, Iceland
- Average sea temperature in September: 10.1°C
The best month for swimming (with the highest average sea temperature) is July (11.7°C).
The coldest month (with the lowest average sea temperature) is March (5.8°C).
Average daylight in September /
Average sunshine in September
Grindavik, Iceland
- Average daylight in September: 13h and 0min
The month with the longest days is June (Average daylight: 20h and 36min).
The month with the shortest days is December (Average daylight: 4h and 30min).
- Average sunshine in September: 4h and 48min
The month with the most sunshine is August (Average sunshine: 7h and 36min).
The month with the least sunshine is January (Average sunshine: 2h and 18min).
Average sunshine days in September
Grindavik, Iceland
- Average sunshine days in September: 8.5 days
The month with the most sunshine days is June (15 days).
The months with the least sunshine days are March and April (7.1 days).
Average UV index in September
Grindavik, Iceland
- Average UV index in September: 3
The month with the highest UV index is July (UV index 4).
The months with the lowest UV index are January, February, March, April, May, October, November and December (UV index 2).
Average cloud cover in September
Grindavik, Iceland
- Average cloud cover in September: 63
The month with the most cloud cover is March (Cloud cover 69).
The months with the least cloud cover are May, July and August (Cloud cover 60).
Average visibility in September
Grindavik, Iceland
- Average visibility in September: 9km
The months with the highest visibility are June and August (10km).
The months with the lowest visibility are January, February, March, April, May, July, September, October, November and December (9km).
