Climate and monthly weather forecastSelfoss, Iceland

Climate and monthly weather forecast

The climate of Selfoss

The petite town of Selfoss, located in the South of Iceland, is significantly influenced by a Marine West Coast climate, designated as Cfc by the Köppen climate classification. This pertains to an environment where rainfall is a common occurrence throughout the year, and summer months maintain a cool ambiance. The monthly weather parameters are indicative of this typical climate in Selfoss.

Two key indicators, average high and low temperatures, show the level of chilliness that persists in Selfoss throughout the year. From 1.5°C (34.7°F) in December to a peak of 13.8°C (56.8°F) in July, it's clear that even in the warmest months, the overarching weather is cool. It’s important to note that temperatures rarely go beyond these bounds. The lowest observed temperatures go from -1.9°C (28.6°F) in December and gradually reach up to 8.9°C (48°F) in July forecasting an undeniable crispness.

With regards to rainfall, Selfoss witnesses precipitation pretty much all year round with January having the maximum of 142mm (5.59") and the minimum in June with 45mm (1.77"). Among snowy months, March sees the highest snowfall with 220mm (8.66"), gradually reducing till becoming negligible from June to October, with November and December again experiencing escalated snowfall.

Relative humidity oscillates between 74% in May and 82% in January and October. Daylight hours extend from 4.5 hours in December to maximum at 20.7 hours in June, also effectively demonstrating Icelandic characteristic long days in summer and short, dark winter days.

The best time to visit Selfoss

A visit to Selfoss during the months of June, July and August can be deemed as the best time bearing in mind the pleasant temperatures. The temperatures lie between 12°C (53.6°F) to 13.8°C (56.8°F) during these months. Notably, the daylight reaches its maximum of 20.7 hours in June allowing visitors to fully explore the picturesque town.

Additionally, these months coincide with the lowest rain and snowfall levels of the year, making outdoor activities far less likely to be impeded by weather. This is complemented with longer sunshine hours, from 7.6 hours in May surging to 7.8 hours in August.

The worst time to visit Selfoss

If visitors are discouraged by lower temperatures and lesser sunlight hours, the period from November to February may not be an optimal time for a visit. During this time, the temperatures fall to frigid levels, with lows going from -1.9°C (28.6°F) in December to highs only reaching 1.5°C (34.7°F). In addition, the daylight hours plunge to as low as 4.5 in December.

Rainfall and snowfall also display a surge during these months. Particularly November and December register an increase in snowfall with 48mm (1.89") and 164mm (6.46") respectively.

Spring weather in Selfoss

Spring, from March to May, in Selfoss brings prolonged sunlight hours and temperatures that move from 2.7°C (36.9°F) to 8.5°C (47.3°F). While the sunsine hours ramp up to 18.4 by May, nights continue to be chilly with temperatures hovering between -0.8°C (30.6°F) in March to 4.3°C (39.7°F) in May. Rainfall reduces over these months, but with an increase in snowfall during the March, travellers should be ready for occasional wintery curves.

Summer weather in Selfoss

Summer months are comparatively temperate with temperatures varying from 13.8°C (56.8°F) in July to 10°C (50°F) in September. Low temperatures at night vary from 8.9°C (48°F) in July to 6.1°C (43°F) in September. These months are also associated with less rainfall, compared to the rest of the year, and zero snowfall, making outdoor activities more feasible.

Autumn weather in Selfoss

Moving into the autumn months of October and November, lower temperatures reappear with highs of 6.5°C (43.7°F) and 3.3°C (37.9°F) respectively. Rainfall increases gradually along with the re-occurrence of snowfall in November making the weather in these months cooler and wetter.

Winter weather in Selfoss

Winter descends on Selfoss with average high temperatures between 2.2°C (36°F) to 1.5°C (34.7°F) for December to February. Lowest temperature recorded is -1.9°C (28.6°F) in December. Snowfall is at its peak in these months, especially notable in December and January with 164mm (6.46") and 143mm (5.63") respectively. Rainfall is also high, indicative of a true Icelandic winter. It is advisable for visitors during this time to be well prepared for a full-fledged Nordic winter experience.

Weather in January

In January, Selfoss experiences temperatures most severe in the annual cycle with a high of 2.2°C (36°F) and a chilly low of -1.2°C (29.8°F). The earliest month of the year tends to be quite humid with cloudy skies and frequent occurrences of rain. Weather in January »

Weather in February

February sees a continuation of the cold weather witnessed in January. Despite this, some slight changes can be observed in the rainfall which decreases to 112mm (4.41") from 142mm (5.59") in January. The snowfall also reduces, but it's still significant, warranting a need for warm attire. Weather in February »

Weather in March

March brings a slight improvement in temperatures in Selfoss compared to the freezing cold January and February, with the highest temperature increasing to 2.7°C (36.9°F). Noteworthy is the increase in snowfall to 220mm (8.66") making it the month with the highest snowfall in the year. Weather in March »

Weather in April

In April, the signs of spring become more apparent in Selfoss. The remarkable decrease in snowfall to 47mm (1.85") from March’s 220mm (8.66") signifies the end of intense winter conditions. The temperature begins to climb, but layering is still recommended as the weather generally stays comfortable but slightly cold. Weather in April »

Weather in May

May is the onset of relatively warmer temperatures in Selfoss. This is the time when the last traces of snow completely vanish, making it the first month of the year without any snowfall. The town starts to take on a more vibrant atmosphere with the lush greenery emerging after the snow melt. Weather in May »

Weather in June

June is a comfortable month in Selfoss with a notable rise in temperatures, reaching up to 12°C (53.6°F). This is also the month with the least rainfall, with total levels dropping down to 45mm (1.77"). The pleasant and primarily dry weather makes it suitable for a variety of outdoor activities, enhancing the overall experience of visitors. Weather in June »

Weather in July

July holds the title of being the warmest month of the year in Selfoss, with the highest average temperature reaching a comfortable 13.8°C (56.8°F). Despite not being the driest, the amount of rainfall is reasonable and does not have a significant impact on outdoor activities. Weather in July »

Weather in August

August sees a slight decline in temperatures in Selfoss from July, but the weather remains fairly warm. While daylight hours slightly decrease, they still make up for a substantial part of the day offering ample time for exploration. Weather in August »

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. Weather in September »

Weather in October

October brings noticeable changes in Selfoss’s weather with temperatures continuing a downward trend. As the city inches closer to the end of autumn, rainfall continues to be significant, laying the groundwork for the upcoming winter season. Weather in October »

Weather in November

November marks the beginning of winter in Selfoss with temperatures dipping down to 3.3°C (37.9°F) at the highest. This is the month when snowfall returns to Selfoss, rising to 48mm (1.89") from zero in the preceding months. Weather in November »

Weather in December

In December, Selfoss witnesses the peak of its winter season with the coldest temperatures in the year. Notably, snowfall climbs up to 164mm (6.46") making it the second-highest snowfall month after March. With the longest nights of the year and limited daylight hours, it is a great time to experience the Nordic winter wonderland. Weather in December »

Updated: Jun 6, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

January and September, with an average relative humidity of 82%, are most humid months.

The month with the most rainfall is January, when the rain falls for 18.6 days and typically aggregates up to 142mm (5.59") of precipitation.

In Selfoss, during the entire year, the rain falls for 208.7 days and collects up to 1105mm (43.5") of precipitation.

January through May, October through December are months with snowfall.

In Selfoss, during the entire year, snow falls for 61.9 days and aggregates up to 825mm (32.48") of snow.

With an average of 2.4h of sunshine, January has the least sunshine of the year.

The month with the most snowfall is March, when snow falls for 13.3 days and typically aggregates up to 220mm (8.66") of snow.

May is the least humid month, with an average relative humidity of 74%.

June is the month with the least rainfall. Rain falls for 15.7 days and accumulates 45mm (1.77") of precipitation.

June through September are months without snowfall.

The month with the longest days is June, with an average of 20h and 42min of daylight.

July is the month when Selfoss experiences its warmest temperatures, averaging a high of 13.8°C (56.8°F) and a low of 8.9°C (48°F).

The month with the highest UV index is July, with an average maximum UV index of 4.

With an average of 7.8h of sunshine, August has the most sunshine of the year.

The month with the lowest UV index is November, with an average maximum UV index of 1.

December, on average, is the coldest month, registering a high temperature of 1.5°C (34.7°F) and a low of -1.9°C (28.6°F).

With an average of 4h and 30min of daylight, December has the shortest days of the year in Selfoss.

Selfoss does not observe Daylight Saving Time (DST). GMT timezone is used throughout the entire year.

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Year J F M A M J J A S O N D

Average temperature
Selfoss, Iceland

Average high temperature in January:
2.2°C
Average high temperature in February:
2.2°C
Average high temperature in March:
2.7°C
Average high temperature in April:
5.5°C
Average high temperature in May:
8.5°C
Average high temperature in June:
12°C

Average high temperature in July:
13.8°C
Average high temperature in August:
13.1°C
Average high temperature in September:
10°C
Average high temperature in October:
6.5°C
Average high temperature in November:
3.3°C
Average high temperature in December:
1.5°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 January:
-1.2°C
Average low temperature in February:
-1.2°C
Average low temperature in March:
-0.8°C
Average low temperature in April:
1.8°C
Average low temperature in May:
4.3°C
Average low temperature in June:
7.6°C

Average low temperature in July:
8.9°C
Average low temperature in August:
8.2°C
Average low temperature in September:
6.1°C
Average low temperature in October:
3.5°C
Average low temperature in November:
0.6°C
Average low temperature in December:
-1.9°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
Selfoss, Iceland

Average pressure in July:
1009.4mbar
Average pressure in August:
1007.6mbar
Average pressure in September:
1003mbar
Average pressure in October:
1003.6mbar
Average pressure in November:
1001.4mbar
Average pressure in December:
998.3mbar

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
Selfoss, Iceland

Average wind speed in January:
24.1km/h
Average wind speed in February:
24.8km/h
Average wind speed in March:
23.5km/h
Average wind speed in April:
22.5km/h
Average wind speed in May:
19.5km/h
Average wind speed in June:
14.9km/h

Average wind speed in July:
14.7km/h
Average wind speed in August:
15.9km/h
Average wind speed in September:
19.8km/h
Average wind speed in October:
21.4km/h
Average wind speed in November:
22.1km/h
Average wind speed in December:
23.6km/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
Selfoss, Iceland

The months with the highest relative humidity are January and September (82%).
The month with the lowest relative humidity is May (74%).

Average rainfall
Selfoss, Iceland

The wettest month (with the highest rainfall) is January (142mm).
The driest month (with the least rainfall) is June (45mm).

Average rainfall days
Selfoss, Iceland

Average rainfall days in January:
18.6 days
Average rainfall days in February:
14.7 days
Average rainfall days in March:
17.3 days
Average rainfall days in April:
19.9 days
Average rainfall days in May:
17.4 days
Average rainfall days in June:
15.7 days

Average rainfall days in July:
19.7 days
Average rainfall days in August:
17.1 days
Average rainfall days in September:
18.7 days
Average rainfall days in October:
17.5 days
Average rainfall days in November:
17.8 days
Average rainfall days in December:
14.3 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
Selfoss, Iceland

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
Selfoss, Iceland

Average snowfall days in January:
11.9 days
Average snowfall days in February:
11.4 days
Average snowfall days in March:
13.3 days
Average snowfall days in April:
5.1 days
Average snowfall days in May:
1.3 days
Average snowfall days in June:
0.1 days

Average snowfall days in July:
0 days
Average snowfall days in August:
0 days
Average snowfall days in September:
0 days
Average snowfall days in October:
1 days
Average snowfall days in November:
5.5 days
Average snowfall days in December:
12.3 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 / Average sunshine
Selfoss, Iceland

Average daylight in January:
5h and 42min
Average daylight in February:
8h and 36min
Average daylight in March:
11h and 48min
Average daylight in April:
15h and 6min
Average daylight in May:
18h and 24min
Average daylight in June:
20h and 42min

Average daylight in July:
19h and 30min
Average daylight in August:
16h and 18min
Average daylight in September:
13h and 0min
Average daylight in October:
9h and 48min
Average daylight in November:
6h and 36min
Average daylight in December:
4h and 30min

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 January:
2h and 24min
Average sunshine in February:
3h and 24min
Average sunshine in March:
4h and 18min
Average sunshine in April:
5h and 18min
Average sunshine in May:
7h and 36min
Average sunshine in June:
7h and 42min

Average sunshine in July:
7h and 24min
Average sunshine in August:
7h and 48min
Average sunshine in September:
4h and 36min
Average sunshine in October:
4h and 18min
Average sunshine in November:
2h and 54min
Average sunshine in December:
2h and 48min

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).