2010 Swedish cold waves
Sweden had a very unusual start and finish to the year 2010, with two consecutive winter cold waves occurring in a single calendar year. Since both events were notable, both are covered in this article.
January–February 2010 cold wave
January
January was in the southern part of the country the coldest for 23 years, the deep freeze of 1987.[1] Some cold weather had finished 2009 and was followed with solid freezing temperatures during the first week of January. The December means were not by any means extreme, but the cold would gradually build up. The intense cold set in between 7 January and 15 January, with Horn as far south as in northern Götaland recording an overnight low of −31.6 °C (−24.9 °F) and Hemavan in the north of the country recording −40.8 °C (−41.4 °F).[1] Relatively less extreme temperatures would follow during the second half of the month, until the final days of January saw another cold snap after some heavy snowfall on 27–28 January.[1] During the final three days of the month low temperatures fell below −20 °C (−4 °F) in most areas far south in the country. Linköping recorded −28.9 °C (−20.0 °F), which was the coldest temperature recorded on this location since the record-breaking 1942 cold wave.[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. In Örebro the maximum temperature recorded was −0.6 °C (30.9 °F) and in Västerås −1 °C (30 °F),[2] which is very rare for an area so far south in Sweden. Remarkably, the far north of the country saw less severe January temperatures than during the 1961-1990 reference period.
February
February was colder than usual, although not matching the January extremes in the southerly parts of the country. The cold was shifted further north, with Nikkaluokta above the polar circle having a monthly mean of −19.9 °C (−3.8 °F) and an average low of −27.3 °C (−17.1 °F).[3] With means below Dalälven (the boundary between Svealand and Norrland) being between −2 °C (28 °F) and −7 °C (19 °F) in most cases the heavy snowfall was a larger issue. 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 frequent snowfall caused havoc for rail transport, with severe delays and cancellations of many lines. 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. 24 February saw the coldest temperature of the winter being recorded in Naimakka in the far north with −42 °C (−44 °F).[6]
March–October
From March onwards the temperatures slowly returned to normal. March is a winter month in the northern parts of the country, but apart from a −33.3 °C (−27.9 °F) reading in
November–December cold wave
November
November 2010 was described as King Bore (very cold winter) moved south by
December
The most extreme cold of the year relative to the normals came in December. 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] Most of the month was solidly below freezing in the entire country, with a few bursts of mild air affecting the deep south. The cold just before Christmas was unprecedented this time of the year in many southern locations. Kalmar saw a record cold −25.6 °C (−14.1 °F) value, Kristianstad another record −24.6 °C (−12.3 °F) value, with Örebro nearly beating its December all-time record cold with −26.6 °C (−15.9 °F), the coldest value for 124 years.[11] During Christmas, the most extreme cold had swept north, with several coastal cities of Norrland recording temperatures around −30 °C (−22 °F).[11] This, albeit highly unusual, did not break any December records. Temperatures throughout the months in the northern parts of the country were quite far below normals, resulting in the cold wave being felt in the entire country. In the south, the New Year's Eve brought milder air, bringing temperatures just above freezing for that night.[11] This marked the end of the cold wave in the south, with January 2011 being a normal winter month. The cold returned to normal levels further north as well, although winter temperatures there are more extreme than a cold wave in the south regardless. The coldest temperature of the month and year was recorded in Nikkaluokta on 20 December, with −42.1 °C (−43.8 °F).[11]
The fallout of December were a lot of new all-time low monthly mean temperatures in southern Sweden. The most extreme new record was set in Arvika, Värmland, with a monthly mean of −14.6 °C (5.7 °F) and a low of −20.2 °C (−4.4 °F).[12] This was more than three degrees colder than the previous December record for the site and less than half a degree below the deep freeze of January 1987, in all possibly the coldest December month there since 1788. 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.[12] The −5.3 °C (22.5 °F) reading of Helsingborg was also almost three degrees colder than the previous record.
The full year
The summer heat wave prevented all-time yearly cold records throughout the country in spite of the two cold waves. The nearest to a new all-time cold record was in Ljungby, which measured 5 °C (41 °F) as opposed to the 4.9 °C (40.8 °F) record of 1987.[13] Although the year was colder than normal throughout the country, it takes a cool summer for those records to be broken, as were in 1942, 1985 and 1987. 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. The same was recorded in Örebro and Västerås further north, climates that most often are as mild as further south.
The year 2010 was a blip in a warming tendency of Swedish winters, the following winters were often delayed by mild autumns, and brief in nature with mild Februarys.
Regions
Norrköping had a record cold December, with a new all-time low for the month being set on December 23 with −24.7 °C (−12.5 °F).[12] Also during the January cold wave, Norrköping did not go above freezing all month. In total, Norrköping had 158 frost days during the year.[13]
Climate data for Norrköping (2010 values only) | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Mean daily maximum °C (°F) | −5.1 (22.8) |
−2.7 (27.1) |
3.5 (38.3) |
11.4 (52.5) |
15.6 (60.1) |
20.8 (69.4) |
25.4 (77.7) |
20.8 (69.4) |
15.7 (60.3) |
9.2 (48.6) |
2.2 (36.0) |
−4.8 (23.4) |
9.3 (48.7) |
Mean daily minimum °C (°F) | −11.4 (11.5) |
−9.1 (15.6) |
−4.1 (24.6) |
1.2 (34.2) |
6.1 (43.0) |
9.5 (49.1) |
14.9 (58.8) |
13.4 (56.1) |
8.2 (46.8) |
2.6 (36.7) |
−2.0 (28.4) |
−11.7 (10.9) |
1.4 (34.5) |
Average precipitation mm (inches) | 41 (1.6) |
59 (2.3) |
21 (0.8) |
22 (0.9) |
67 (2.6) |
32 (1.3) |
82 (3.2) |
95 (3.7) |
41 (1.6) |
57 (2.2) |
93 (3.7) |
41 (1.6) |
651 (25.6) |
Mean monthly sunshine hours | 36 | 30 | 161 | 191 | 215 | 298 | 285 | 150 | 150 | 118 | 53 | 37 | 1,724 |
Source: SMHI Monthly Data 2002-2015[14] |
Climate data for Norrköping (2002-2015 temperatures; 1961-1990 precipitation & sunshine) | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Mean daily maximum °C (°F) | 0.8 (33.4) |
1.2 (34.2) |
5.6 (42.1) |
12.0 (53.6) |
16.7 (62.1) |
20.4 (68.7) |
23.1 (73.6) |
21.8 (71.2) |
17.5 (63.5) |
10.7 (51.3) |
5.8 (42.4) |
2.5 (36.5) |
11.5 (52.7) |
Mean daily minimum °C (°F) | −4.3 (24.3) |
−4.4 (24.1) |
−2.5 (27.5) |
1.4 (34.5) |
6.1 (43.0) |
10.0 (50.0) |
13.3 (55.9) |
12.4 (54.3) |
8.6 (47.5) |
3.8 (38.8) |
1.1 (34.0) |
−2.3 (27.9) |
3.7 (38.7) |
Average precipitation mm (inches) | 31.7 (1.25) |
23.1 (0.91) |
27.3 (1.07) |
29.7 (1.17) |
36.4 (1.43) |
49.7 (1.96) |
61.9 (2.44) |
59.0 (2.32) |
55.3 (2.18) |
47.3 (1.86) |
47.7 (1.88) |
38.9 (1.53) |
508.2 (20.01) |
Mean monthly sunshine hours | 40 | 70 | 100 | 175 | 259 | 277 | 253 | 222 | 149 | 96 | 57 | 36 | 1,734 |
Source 1: SMHI[15] | |||||||||||||
Source 2: SMHI Monthly Data 2002-2015[16] |
Svealand
Climate data for Stockholm (2010 values only) | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Mean daily maximum °C (°F) | −4.8 (23.4) |
−3.0 (26.6) |
3.0 (37.4) |
10.8 (51.4) |
16.4 (61.5) |
21.2 (70.2) |
26.5 (79.7) |
21.3 (70.3) |
15.5 (59.9) |
8.8 (47.8) |
2.2 (36.0) |
−4.2 (24.4) |
9.4 (48.9) |
Mean daily minimum °C (°F) | −9 (16) |
−7.7 (18.1) |
−3.1 (26.4) |
2.5 (36.5) |
7.3 (45.1) |
11.1 (52.0) |
17.2 (63.0) |
14.1 (57.4) |
9.3 (48.7) |
4.2 (39.6) |
−1.5 (29.3) |
−9.3 (15.3) |
2.9 (37.2) |
Average precipitation mm (inches) | 26 (1.0) |
29 (1.1) |
22 (0.9) |
23 (0.9) |
31 (1.2) |
33 (1.3) |
74 (2.9) |
105 (4.1) |
73 (2.9) |
34 (1.3) |
54 (2.1) |
45 (1.8) |
549 (21.6) |
Mean monthly sunshine hours | 38 | 37 | 165 | 201 | 247 | 326 | 302 | 172 | 162 | 130 | 54 | 30 | 1,864 |
Source: SMHI average data 2002-2015[17] |
Climate data for Stockholm, temperature 2002-2015; precipitation and sunshine 1961-1990 | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Mean daily maximum °C (°F) | 0.5 (32.9) |
0.8 (33.4) |
4.7 (40.5) |
11.3 (52.3) |
16.6 (61.9) |
20.7 (69.3) |
23.8 (74.8) |
22.2 (72.0) |
16.9 (62.4) |
10.1 (50.2) |
5.7 (42.3) |
2.4 (36.3) |
11.2 (52.2) |
Mean daily minimum °C (°F) | −3.1 (26.4) |
−3.3 (26.1) |
−1.2 (29.8) |
2.8 (37.0) |
7.4 (45.3) |
11.4 (52.5) |
15.1 (59.2) |
14.3 (57.7) |
10.2 (50.4) |
5.2 (41.4) |
2.0 (35.6) |
−1.2 (29.8) |
4.9 (40.8) |
Average precipitation mm (inches) | 39 (1.5) |
27 (1.1) |
29 (1.1) |
29 (1.1) |
32 (1.3) |
55 (2.2) |
65 (2.6) |
59 (2.3) |
52 (2.0) |
49 (1.9) |
47 (1.9) |
45 (1.8) |
531 (20.9) |
Mean monthly sunshine hours | 40 | 72 | 135 | 185 | 276 | 292 | 260 | 221 | 154 | 99 | 54 | 33 | 1,821 |
Source 1: SMHI average data 2002-2015[18] | |||||||||||||
Source 2: SMHI[19] |
Climate data for Örebro Airport (2010 values only) | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Mean daily maximum °C (°F) | −6.5 (20.3) |
−3.5 (25.7) |
2.8 (37.0) |
11.5 (52.7) |
16.5 (61.7) |
21.0 (69.8) |
24.6 (76.3) |
20.7 (69.3) |
15.9 (60.6) |
9.5 (49.1) |
1.2 (34.2) |
−5.6 (21.9) |
9.0 (48.2) |
Mean daily minimum °C (°F) | −13.6 (7.5) |
−10.5 (13.1) |
−4.8 (23.4) |
1.1 (34.0) |
5.7 (42.3) |
8.9 (48.0) |
13.8 (56.8) |
12.8 (55.0) |
6.5 (43.7) |
2.0 (35.6) |
−3.4 (25.9) |
−13.7 (7.3) |
0.4 (32.7) |
Average precipitation mm (inches) | 31 (1.2) |
82 (3.2) |
25 (1.0) |
22 (0.9) |
115 (4.5) |
25 (1.0) |
166 (6.5) |
83 (3.3) |
42 (1.7) |
30 (1.2) |
88 (3.5) |
31 (1.2) |
740 (29.1) |
Source: SMHI average data 2002-2015[17] |
Climate data for Örebro Airport (2002-2015 temperatures and 1961-1990 precipitation normals) | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Mean daily maximum °C (°F) | 0.3 (32.5) |
0.7 (33.3) |
5.4 (41.7) |
12.1 (53.8) |
16.9 (62.4) |
20.6 (69.1) |
23.1 (73.6) |
21.8 (71.2) |
17.2 (63.0) |
10.3 (50.5) |
5.3 (41.5) |
1.9 (35.4) |
11.3 (52.3) |
Mean daily minimum °C (°F) | −5.6 (21.9) |
−5.4 (22.3) |
−3.2 (26.2) |
1.0 (33.8) |
5.7 (42.3) |
9.4 (48.9) |
12.5 (54.5) |
11.2 (52.2) |
7.3 (45.1) |
2.7 (36.9) |
0.5 (32.9) |
−3.6 (25.5) |
2.7 (36.9) |
Average precipitation mm (inches) | 48.4 (1.91) |
34.9 (1.37) |
35.8 (1.41) |
40.1 (1.58) |
43.7 (1.72) |
55.5 (2.19) |
76.2 (3.00) |
74.3 (2.93) |
74.5 (2.93) |
62.3 (2.45) |
65.6 (2.58) |
50.1 (1.97) |
661.4 (26.04) |
Source 1: SMHI Precipitation normals 1961-1990[20] | |||||||||||||
Source 2: SMHI average data 2002-2015[18] |
Southern Norrland
Hudiksvall that normally has a very mild climate considering its northerly latitude saw one of its coldest years on record. Hudiksvall was the northernmost part of the country that saw a record cold December, although nearby Delsbo had seen a much colder value 17 years before Hudiksvall's weather station opened in 1932.[12] Both cold waves also saw high snowfall. In total Hudiksvall had 179 frost days during 2010.[13]
Climate data for Hudiksvall (2010 values only) | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Mean daily maximum °C (°F) | −6.4 (20.5) |
−4.7 (23.5) |
2.7 (36.9) |
9.2 (48.6) |
15.0 (59.0) |
18.6 (65.5) |
24.2 (75.6) |
19.6 (67.3) |
15.8 (60.4) |
9.4 (48.9) |
0.0 (32.0) |
−6.2 (20.8) |
8.1 (46.6) |
Mean daily minimum °C (°F) | −12.7 (9.1) |
−14.0 (6.8) |
−5.0 (23.0) |
−0.6 (30.9) |
4.6 (40.3) |
7.5 (45.5) |
13.7 (56.7) |
11.4 (52.5) |
5.6 (42.1) |
1.0 (33.8) |
−6.1 (21.0) |
−14.0 (6.8) |
−0.7 (30.7) |
Average precipitation mm (inches) | 49 (1.9) |
82 (3.2) |
14 (0.6) |
18 (0.7) |
42 (1.7) |
152 (6.0) |
42 (1.7) |
106 (4.2) |
39 (1.5) |
16 (0.6) |
68 (2.7) |
122 (4.8) |
750 (29.5) |
Source: SMHI climate data 2002-2015[21] |
Climate data for Hudiksvall (2002-2015 temperatures; 1961-1990 precipitation) | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Mean daily maximum °C (°F) | −0.8 (30.6) |
0.2 (32.4) |
4.9 (40.8) |
10.4 (50.7) |
14.9 (58.8) |
19.2 (66.6) |
22.5 (72.5) |
21.1 (70.0) |
16.7 (62.1) |
9.6 (49.3) |
4.0 (39.2) |
0.7 (33.3) |
10.2 (50.4) |
Mean daily minimum °C (°F) | −7.5 (18.5) |
−7.3 (18.9) |
−4.3 (24.3) |
−0.4 (31.3) |
4.2 (39.6) |
8.4 (47.1) |
12.2 (54.0) |
11.0 (51.8) |
6.5 (43.7) |
1.5 (34.7) |
−1.7 (28.9) |
−5.7 (21.7) |
1.4 (34.5) |
Average precipitation mm (inches) | 50.2 (1.98) |
36.8 (1.45) |
38.9 (1.53) |
38.4 (1.51) |
38.4 (1.51) |
49.0 (1.93) |
63.2 (2.49) |
72.7 (2.86) |
69.8 (2.75) |
58.6 (2.31) |
63.1 (2.48) |
54.9 (2.16) |
635.9 (25.04) |
Source 1: SMHI precipitation average 1961-1990[22] | |||||||||||||
Source 2: SMHI climate data 2002-2015[23] |
References
- ^ a b c d "January 2010 summary" (in Swedish). SMHI. Archived from the original on 12 February 2010. Retrieved 19 July 2016.
- ^ "January 2010 Temperature & Wind" (PDF) (in Swedish). SMHI. Retrieved 19 July 2016.
- ^ "February 2010 Temperature & Wind" (PDF) (in Swedish). SMHI. Retrieved 19 July 2016.
- ^ "SMHI February 2010 summary" (in Swedish). SMHI. Archived from the original on 14 August 2016. Retrieved 19 July 2016.
- ^ "February 2010 Precipitation & Sunshine" (PDF) (in Swedish). SMHI. Retrieved 19 July 2016.
- ^ "February 2010 Temperature & Wind" (PDF) (in Swedish). SMHI. Retrieved 19 July 2016.
- ^ "July 2010 Temperature & Wind" (PDF) (in Swedish). SMHI. Retrieved 19 July 2016.
- ^ a b "SMHI November 2010 summary" (in Swedish). SMHI. Retrieved 19 July 2016.
- ^ "November 2010 Temperature & Wind" (PDF) (in Swedish). SMHI. Retrieved 19 July 2016.
- ^ "November 2010 Temperature & Wind" (PDF) (in Swedish). SMHI. Retrieved 19 July 2016.
- ^ a b c d e "SMHI December 2010 summary" (in Swedish). SMHI. Retrieved 19 July 2016.
- ^ a b c d "December 2010 Temperature & Wind" (PDF) (in Swedish). SMHI. Retrieved 19 July 2016.
- ^ a b c d e "Temperature summary for 2010" (PDF) (in Swedish). SMHI. Retrieved 19 July 2016.
- ^ "SMHI Monthly Data 2002-2015". SMHI. 22 July 2016. Archived from the original on 20 February 2015. Retrieved 19 July 2016.
- ^ "Norrköping Climate Details". Swedish Metereological and Hydrological Institute (Norrköping code 8636). Archived from the original on 28 September 2018. Retrieved 22 July 2016.
- ^ "Statistik från Väder och Vatten". SMHI. 22 February 2015. Archived from the original on 20 February 2015. Retrieved 19 July 2016.
- ^ a b "Annual and Monthly Statistics". SMHI. 19 July 2016. Archived from the original on 20 February 2015. Retrieved 19 July 2016.
- ^ a b "Annual and Monthly Statistics". SMHI. 9 January 2016. Archived from the original on 20 February 2015. Retrieved 19 July 2016.
- ^ "Sunshine Hours of Stockholm" (PDF). Sveriges Meteorologiska och Hydrologiska Institut. Archived from the original (PDF) on 23 May 2019. Retrieved 19 March 2012.
- ^ "Average Precipitation for Stations (Swedish)". Swedish Metereological and Hydrological Institute (Örebro code 9562). Archived from the original on 2 May 2018. Retrieved 20 February 2015.
- ^ "SMHI climate data 2002-2015". SMHI. 24 July 2016. Archived from the original on 20 February 2015. Retrieved 19 July 2016.
- ^ "SMHI precipitation average 1961-1990". Swedish Metereological and Hydrological Institute (Hudiksvall code 11 744). Archived from the original on 2 May 2018. Retrieved 19 July 2016.
- ^ "SMHI climate data 2002-2015". SMHI. 12 March 2016. Archived from the original on 20 February 2015. Retrieved 19 July 2016.