Temperatures in September
It's cool in September in Keflavík with an average temperature of 11°C. Temperatures this month range from a low of 9°C to a high of 13°C. At night, you can expect temperatures between 5°C and 9°C.
Max and Min Temperatures per Day
This chart shows the daily maximum and minimum temperatures in degrees Celsius for Keflavík in September. The red line indicates the max temperatures, and the blue line shows the minimums.
Start of September
The month of September starts in Keflavík with cool temperatures, averaging around 13°C during the day and nights close to 9°C. You can expect regular precipitation, but there’s also a chance for some sunny days in the first days of the month. Go for a warm coat, jumper or cardigan, and long trousers.
Mid-September
By mid-September, the average daytime temperature drops to around 12°C, with nights close to 8°C. The chance of precipitation is high during this period.
End of September
By the end of September, the average daytime temperature in Keflavík will be around 11°C, with nights close to 6°C. There’s a significant chance of many days with precipitation.
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Precipitation in September
In September, there is an average of 153 mm of precipitation, spread over 18 days. Of the total precipitation, about 0,1 cm falls as snow in September. The wind speed is around 5 Bft, mostly coming from the South.
The average precipitation chance this month is 60% per day. Though that seems frequent, the weather’s variable. There are also a few days with lower precipitation chances.
Precipitation Chance
This chart shows the daily precipitation chance (in percentages) in September for Keflavík. 0% means it never rained on that day in the past 10 years, and 100% means it rained every day. All values in between represent the average chance of precipitation on that day.
Keflavík in September |
London | ||
|---|---|---|---|
 Average Temperature |
11°C | 20°C | |
 High Temp |
13°C | 22°C | |
| Low Temp |
9°C | 17°C | |
 Total Precipitation |
153 mm | 44 mm | |
| Rainy Days |
18 days | 8 days | |
 Total Snowfall |
0,1 cm | 0 cm | |
| Snowy Days |
1 day | 0 days | |
August
UV index
The UV index is a maximum of 3 this month. That's a moderate value on the intensity scale of 1 to 11. Unprotected skin can burn in about 30 minutes.
Is September a good time to visit Keflavík?
After some sun? Then September isn’t the best time to be in Keflavík. There’s too much chance of rain this month.
Temperature records for Keflavík in September
With 18°C, Keflavík hit the highest temperature in the last 10 years in September 2019. The lowest daytime temperature in this month was 4°C in 2021. The extreme night temperatures ranged from a low of -5°C to a high of 13°C.
Check out the climate of Keflavík for all months and discover the best travel time
Curious about the climate in other parts of Iceland? Check out the weather and climate in places like Reykjavík, Vík, or have a look at other destinations in Iceland.
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Daily Temperature in September in Keflavík
This chart shows the average daily temperatures, both day and night, for each day in September in Keflavík, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Daily Precipitation in September in Keflavík
The chart below shows the average daily precipitation in September for Keflavík, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for September, you can expect around 18 days of rain in Keflavík.
Daily Snowfall in September in Keflavík
This chart shows the average daily snowfall in September in Keflavík, measured in centimetres. The bottom of the chart shows the days of the month. The data is based on historical measurements and gives an idea of the average snowfall in September.
Daily UV Index in September in Keflavík
This chart shows the average daily UV index in September in Keflavík, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in September in Keflavík Over the Years
This chart shows the average temperature in September in Keflavík, measured in degrees Celsius, over the past years.
Total Precipitation in September in Keflavík Over the Years
This chart shows the average precipitation in September in Keflavík, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Snowfall in September in Keflavík per year
This chart shows the average snowfall in September in Keflavík, measured in centimetres, over the past years.
Daily climate in September for Keflavík
Click on a specific day in September for detailed info on the typical weather on that day in Keflavík. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in September in Keflavík
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Average Weather in Keflavík by Month
Click on a month below to see detailed weather info for Keflavík. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
