September weather forecastStykkishólmur, Iceland
September
Weather in September
With September comes the turn of the season in Stykkishólmur, as the tranquillity of summer gives way to the crispness of autumn. Rainfall increases and peaks at 39mm (1.54"), the highest in the year, and more than the previous month of August. With the change in season, temperatures also drop, although the decline in daylight is more noticeable. Despite the weather simmering down, the city’s natural grandeur, under autumn leaves and stormy skies, is an enchanting spectacle.Temperature
In September, Stykkishólmur experiences a barely noticeable shift in meteorological conditions, with average high-temperatures moving from 11.2°C (52.2°F) in August to a chilly 8.5°C (47.3°F). In September, Stykkishólmur experiences a marginal drop in temperature, with averages of 6°C (42.8°F) at night.Humidity
The average relative humidity in September in Stykkishólmur is 82%.Rainfall
In Stykkishólmur, in September, it is raining for 14.6 days, with typically 39mm (1.54") of accumulated precipitation. Throughout the year, in Stykkishólmur, there are 139.6 rainfall days, and 351mm (13.82") of precipitation is accumulated.Snowfall
In Stykkishólmur, snow does not fall in June through September.Sea temperature
In September, the average sea temperature is 8.8°C (47.8°F).Note: In 8.8°C (47.8°F), cold shock and rapid breathing can occur when swimming at temperatures below 10°C (50°F).
Daylight
In Stykkishólmur, the average length of the day in September is 13h and 3min.On the first day of September, sunrise is at 06:12 and sunset at 20:49. On the last day of the month, sunrise is at 07:39 and sunset at 19:01 GMT.
Sunshine
The average sunshine in September in Stykkishólmur is 4.3h.UV index
The average daily maximum UV index in September is 2. A UV Index reading of 2, and below, represents a minimal health hazard from unsafe exposure to UV radiation for average individuals.Note: In September, the maximum UV index of 2 suggests these recommendations:
Despite the majority tolerating prolonged sun exposure, those with sensitive skin, infants, and children demand continual protection. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage. Guard yourself! Snow reflection can almost double the UV radiation from the Sun.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Stykkishólmur, Iceland
- Average high temperature in September: 8.5°C
The warmest month (with the highest average high temperature) is July (12.1°C).
The month with the lowest average high temperature is December (0.7°C).
- Average low temperature in September: 6°C
The month with the highest average low temperature is July (8.3°C).
The coldest months (with the lowest average low temperature) are February and December (-1.8°C).
Average pressure in September
Stykkishólmur, Iceland
- Average pressure in September: 1003mbar
The month with the highest atmospheric pressure is June (1014.1mbar).
The month with the lowest atmospheric pressure is January (996.7mbar).
Average wind speed in September
Stykkishólmur, Iceland
- Average wind speed in September: 18.9km/h
The windiest month (with the highest average wind speed) is February (25.9km/h).
The calmest month (with the lowest average wind speed) is June (14.6km/h).
Average humidity in September
Stykkishólmur, Iceland
- Average humidity in September: 82%
The months with the highest relative humidity are January, February and October (83%).
The month with the lowest relative humidity is May (77%).
Average rainfall in September
Stykkishólmur, Iceland
- Average rainfall in September: 39mm
The wettest month (with the highest rainfall) is January (40mm).
The driest month (with the least rainfall) is July (17mm).
Average rainfall days in September
Stykkishólmur, Iceland
- Average rainfall days in September: 14.6 days
The month with the highest number of rainy days is October (15.7 days).
The month with the least rainy days is February (9.1 days).
Average snowfall in September
Stykkishólmur, Iceland
- Average snowfall in September: 0mm
The month with the highest snowfall is March (97mm).
The months with the least snowfall are June, July, August and September (0mm).
Average snowfall days in September
Stykkishólmur, Iceland
- Average snowfall days in September: 0.5 days
The month with the highest number of snowfall days is January (11.6 days).
The months with the least snowfall days are July and August (0 days).
Average sea temperature in September
Stykkishólmur, Iceland
- Average sea temperature in September: 8.8°C
The best month for swimming (with the highest average sea temperature) is August (10.3°C).
The coldest month (with the lowest average sea temperature) is March (2.1°C).
Average daylight in September /
Average sunshine in September
Stykkishólmur, Iceland
- Average daylight in September: 13h and 6min
The month with the longest days is June (Average daylight: 21h and 42min).
The month with the shortest days is December (Average daylight: 3h and 48min).
- Average sunshine in September: 4h and 18min
The month with the most sunshine is May (Average sunshine: 7h and 18min).
The month with the least sunshine is June (Average sunshine: 0h and 48min).
Average sunshine days in September
Stykkishólmur, Iceland
- Average sunshine days in September: 12.5 days
The months with the most sunshine days are June and July (16.8 days).
The month with the least sunshine days is March (9.1 days).
Average UV index in September
Stykkishólmur, Iceland
- Average UV index in September: 2
The months with the highest UV index are June, July and August (UV index 3).
The months with the lowest UV index are January, February, April, October, November and December (UV index 1).
Average cloud cover in September
Stykkishólmur, Iceland
- Average cloud cover in September: 67
The month with the most cloud cover is March (Cloud cover 72).
The months with the least cloud cover are May and June (Cloud cover 61).
Average visibility in September
Stykkishólmur, Iceland
- Average visibility in September: 9km
The months with the highest visibility are June and July (10km).
The months with the lowest visibility are January, February, March, April, May, August, September, October, November and December (9km).
