September weather forecastSelfoss, Iceland
September
Weather in September
September marks the onset of autumn in Selfoss with temperatures starting to decrease and moving closer to 10°C (50°F). Rainfall increases from August's 77mm (3.03") to 95mm (3.74"), indicating the transition towards the rainy season. This month also brings along an increase in wind speed, adding a chill factor especially in the evenings. Despite these changes, daylight hours remain fairly substantial providing ample opportunities to explore the city in day time. Depending on weather preferences, visitors may find this transitionary period a unique time to visit.Temperature
September signals a slight drop in average high-temperature, sliding from August's refreshing 13.1°C (55.6°F) to a cool 10°C (50°F). In Selfoss, the month of September records an average minimum temperature of 6.1°C (43°F), a slight dip from the daily highs.Humidity
The months with the highest humidity are January and September, with an average relative humidity of 82%.Rainfall
In September, the rain falls for 18.7 days. Throughout September, 95mm (3.74") of precipitation is accumulated. Throughout the year, there are 208.7 rainfall days, and 1105mm (43.5") of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 13h and 0min.On the first day of September, sunrise is at 06:09 and sunset at 20:38. On the last day of the month, sunrise is at 07:31 and sunset at 18:55 GMT.
Sunshine
In Selfoss, the average sunshine in September is 4.6h.UV index
In September, the average daily maximum UV index is 2. A UV Index value of 2, and less, symbolizes a minimal health hazard from unsafe exposure to UV radiation for the ordinary person.Note: In September, the maximum UV index of 2 translates into these guidelines:
Most individuals face no major issues with lengthy exposure to the sun, but children, infants, and individuals with fair skin always require protection. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Selfoss, Iceland
- Average high temperature in September: 10°C
The warmest month (with the highest average high temperature) is July (13.8°C).
The month with the lowest average high temperature is December (1.5°C).
- Average low temperature in September: 6.1°C
The month with the highest average low temperature is July (8.9°C).
The coldest month (with the lowest average low temperature) is December (-1.9°C).
Average pressure in September
Selfoss, Iceland
- Average pressure in September: 1003mbar
The month with the highest atmospheric pressure is June (1013.8mbar).
The month with the lowest atmospheric pressure is January (996.8mbar).
Average wind speed in September
Selfoss, Iceland
- Average wind speed in September: 19.8km/h
The windiest month (with the highest average wind speed) is February (24.8km/h).
The calmest month (with the lowest average wind speed) is July (14.7km/h).
Average humidity in September
Selfoss, Iceland
- Average humidity in September: 82%
The months with the highest relative humidity are January and September (82%).
The month with the lowest relative humidity is May (74%).
Average rainfall in September
Selfoss, Iceland
- Average rainfall in September: 95mm
The wettest month (with the highest rainfall) is January (142mm).
The driest month (with the least rainfall) is June (45mm).
Average rainfall days in September
Selfoss, Iceland
- Average rainfall days in September: 18.7 days
The month with the highest number of rainy days is April (19.9 days).
The month with the least rainy days is December (14.3 days).
Average snowfall in September
Selfoss, Iceland
- Average snowfall in September: 0mm
The month with the highest snowfall is March (220mm).
The months with the least snowfall are June, July, August and September (0mm).
Average snowfall days in September
Selfoss, Iceland
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is March (13.3 days).
The months with the least snowfall days are July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Selfoss, Iceland
- Average daylight in September: 13h and 0min
The month with the longest days is June (Average daylight: 20h and 42min).
The month with the shortest days is December (Average daylight: 4h and 30min).
- Average sunshine in September: 4h and 36min
The month with the most sunshine is August (Average sunshine: 7h and 48min).
The month with the least sunshine is January (Average sunshine: 2h and 24min).
Average sunshine days in September
Selfoss, Iceland
- Average sunshine days in September: 9.7 days
The month with the most sunshine days is June (12.3 days).
The month with the least sunshine days is January (5.5 days).
Average UV index in September
Selfoss, Iceland
- Average UV index in September: 2
The month with the highest UV index is July (UV index 4).
The month with the lowest UV index is November (UV index 1).
Average cloud cover in September
Selfoss, Iceland
- Average cloud cover in September: 64
The month with the most cloud cover is March (Cloud cover 67).
The months with the least cloud cover are May and August (Cloud cover 59).
Average visibility in September
Selfoss, Iceland
- Average visibility in September: 9km
The month with the highest visibility is June (10km).
The months with the lowest visibility are January, February and March (8km).
