Summer weather is coming, but the water will be cold

SørengaSun, clouds and swimming at Sørenga in Oslo.Photo: Gorm Kallestad / NTB scanpix

Western Norway will experience intense summer heat in the coming days, upwards of 30 degrees. But the swimming water will remain unusually cool for July.


‘The swimming temperatures have undoubtedly been cool for July, compared to last year,’ said Svein Sundby, a researcher at the Institute of Marine Research.

‘This year, it was almost warmer to swim in the sea in June than in July, at least on the southern coast.

Temperatures fluctuate dramatically from day to day, week to week and from year to year, but there’s little to suggest that the unusually low July water temperatures will change in the short term, although several regions will have high air temperatures within the next few days’.

Wind dissipates the heat at sea

The southerners have had a lot of good weather so far this summer. Yet, yesterday’s measurements showed that on Wednesday, the sea temperature was completely down to 12 and 15 degrees along the southern coast.

‘The southern wind at Sørlandet has caused cold water from the deep to affect the surface swimming water. Heavy wind from the south and west blows the heated water at the surface out to sea.

This also applies to the coast in the Grenlands area.

On the west coast, and the coast of northern Norway, north winds, which are often associated with sun and fine weather, will also cause the hot surface water to disappear out to sea.

Cold river water flows into the sea

Swimming temperatures are not only determined by the general weather, or wind directions. They are also affected by freshwater flowing from rivers into the sea, and the temperature of the Gulf Stream.


Northern Norway often has very cold swimming water.

‘It has to do with air temperature, and the Gulf Stream gets colder the farther north it comes,’ said Sundby.

The large watercourses in Southeastern Norway all arrive on the short coastline from Hvaler to Langesund. This applies to Glomma, Numedalslågen and the Skiensvassdraget. Snow from the mountains of southern Norway melts, flows into the sea, and contributes to lower temperatures.

‘The best conditions for good swimming temperatures are not, surprisingly, sunny and windy,’ said Sundby.

Southern Norway is the week’s weather winner

Southern Norway will get the best weather, especially on Thursday, when it’ll get hot in Vestlandet, reaching up to 30 degrees.

‘The hot weather will rise up up towards Trøndelag counties on Thursday too,’ said Ida Fossli, Deputy State Meteorologist at the Meteorological Institute.

‘Friday will also be a nice, fine day in southern Norway, except on the south coast at Rogaland and Telemark, due to rain coming in.

In northern Norway, the weather is quite cloudy, and has remained so for many days. The rain is clearing gradually, but the clouds will hang in the sky again towards the weekend.

Summer weather for the weekend

At the weekend, there will be some rain in southern Norway, up as far as Stad and Dovre, but further north, fine weather is expected.

‘It won’t be as hot as Thursday, but still summery at 25 degrees,’ said Fossli.

In Northern Norway, Nordland will have good weather by Friday; it’ll stay fine on Saturday, and reach Troms.

‘This Sunday, it’ll be warm and sunny in Troms, just over 20 degrees at the weekend,’ said Fossli.

The best sea swimming temperatures on Wednesday no longer got up to where they were at during the 19th century, when the sea was often warmer. In many places in the country, temperatures in the sea are down to 12 and 14 degrees.

© NTB Scanpix / Norway Today