2010 Swedish cold waves
[1] The end result of January was that capital Stockholm that is inside an urban heat island did not record a single temperature above 0.0 °C (32.0 °F) all month.
Westerlies mixed with the colder than usual air made snowfall abundant during the low-pressure systems' resurgence on the west coast.
[4] Although no February precipitation records were broken,[5] an unusual amount of what fell came as snow in the southerly part of the country, where winter highs normally are above freezing.
The night of 22 February was among the coldest of the entire cold wave, with Stockholm recording −21.0 °C (−5.8 °F) inside the urban heat island and −27.5 °C (−17.5 °F) being measured in Örebro.
Sweden was affected less by the intense 2010 Northern Hemisphere summer heat waves than Russia, Finland or Germany were, although some hot temperatures were recorded and Lund had a July mean of 20.9 °C (69.6 °F) and Stockholm had one of the hottest months in the country's history with 21.2 °C (70.2 °F).
Such were the swings that Stockholm's 2010 values were in some ways comparable to inland areas in southern Ontario in Canada, known for its very continental climates.
Even more remarkable were the five ice days measured in Malmö, with southern Scania often averaging means above freezing even in January.
Although January 2010 had been slightly colder than what was recorded in the south of the country, December is normally a month that is above freezing during daytime in southern Sweden due to its seasonal lag that a maritime climate brings.
Although the month started out quite mild, temperatures plummeted to extreme cold as winter solstice and Christmas neared.
[11] During Christmas, the most extreme cold had swept north, with several coastal cities of Norrland recording temperatures around −30 °C (−22 °F).
Among other new December record cold months were found in Örebro, Norrköping, Linköping, Gothenburg, Malmö, Kalmar, Växjö, Kristianstad, Halmstad, Varberg, Borås, Vänersborg, Helsingborg, Ljungby, Visby and many maritime coastal stations such as Falsterbo, Landsort and the extreme points of Öland.
In spite of this, it is extremely rare for inland locations in Götaland in the south to record yearly means below 5 °C (41 °F), as was done at some stations such as Jönköping, Vänersborg and Ulricehamn.
[13] Stockholm did not set any cold records, but still had a colder year than usual, with the entire January month being below freezing.
[13] In addition, Stockholm also had a very hot July, being most affected by the 2010 Northern Hemisphere summer heat waves than any other Swedish location.
This moderated the yearly average, along with the urban heat island that always render milder overnight lows than in the rural Mälar valley.
