Post by Lommaren on Feb 11, 2019 8:44:25 GMT -5
Luleå is a town more or less 250 km (155 miles or so) north of Umeå on the Bay of Bothnia. Its region (Luleå/Oulu/Haparanda et cetera) is the most poleward coastline with average summer highs above 20°C in the world, as a result of Gulf Stream air travelling inland from the mild Norwegian coastline and a substantial landmass to the east of said sea, where first Finland and then Russia ensue for thousands of miles.
During the 2010's, Luleå has had rather interesting weather to say the least. I assume Babu will be interested in this and especially the rather high sunshine numbers and how often it actually is Dfb.
2010 was a very cold year for the location with a 0.9°C mean. February didn't rise above freezing at all, but January did, unlike areas way farther south. Even so, logically the averages were colder than lower Scandinavia. Summer was rather cool, with July being the exception, it being rather normal. In spite of this, Luleå was way cooler than the Baltic Sea coastal region in relation to the expected averages, Luleå being unaffected and not reaching 25°C all month of July. Even so, it did actually happen, in May! November and December were way below average and cold. December became the second month of the year that didn't go above freezing. Also, it ended up with five months below -6.3°C means and with lows below -11.4°C as well as the coldest autumn month of the decade so far in that year's November.
2011 continued the cold start to the winter, with January and February being below average, with the winter peaking in the latter month with -11.3/-20.1 averages. June saw a strong heat burst with a 30°C reading, which is about as warm as it gets for Luleå. July then saw very mild overnight lows and continued the sunny trend. Similar to the rest of Sweden, the autumn was rather mild. In Luleå's case it was also both rather rainy (September) and snowy (December). The low diurnals from the low-pressure in September resulted in the year ending up a Dfb.
2012 was another cold year for Luleå, although it didn't match the previous years' winters for averages. That being said, February saw a -34.5°C cold snap along the frozen bay, before March turned milder than usual and April saw the cold strike back. Summer was a bit of nothing. I recall visiting in between Umeå and there in July that year and it felt like an autumn day. At the end of summer, Luleå hadn't reached 23°C once and was consistently below average. A rainy autumn ultimately culminated in a cold December that was largely a snowout. At those temperatures, I'd be surprised if it wasn't solidly above 100 cm just for December alone. Nevertheless, the cover on the ground peaked at a mere 55 cm.
2013 was another largely no-show summer, although Luleå recorded a rather sensational coastal 27.3°C high in May. Ultimately, the mild nature of September ensured another Dfb without any months recording 20°C highs and the four warmest months peaking at a mere 24°C. The otherwise most notable feature of 2013 was that March was the coldest month, with -9°C means and that spring turned around rapidly from April to May.
2014 saw the first truly warm summer month of the decade and it was rather spectacular for its high coastal latitude, with July ending up at a remarkable 24.0/15.0 for averages. It also saw the warmest temperature of the decade with a 30.8°C reading. Aside from that, the most notable feature of the year was the extremely mild February for the location, with average highs remaining above freezing and the intensive cloud cover enabling lows to be as mild as -3°C, which is close to 10°C milder than usual. The end result was that February was just the fourth coldest month of the year and also that September in the wake of the warm summer remained above 10°C means, thus becoming Dfb for the third time in four years. Average lows remained above freezing for the full year, something very rare for the Swedish high-latitude coastline.
2015 was the warmest year of the decade with 4.5°C means and once more with lows above freezing. The year started with the strongest snowout of the decade, with 154 mm of precipitation in January for -4.8/-12.9 averages. The 100 cm snow cover I'm sure would've made 🖕🏿Mörön🖕🏿 feel like it was Hokkaido! In February this further expanded to 110 cm of snow on the ground. Spring started warm, but was then delayed. Summer also saw a lot of lag, rarely enough August was the warmest month with 20.0/11.3 averages. A rather stable September that didn't once go above 17.7°C kept means above the threshold to be Dfb for the fourth time in five years. Ultimately, December turned out to be a winter month after all, in contrast to lower Scandinavia's extended autumn, but it was still quite a bit above average. Unlike the then national sunshine records on Gotland, Luleå had a quite gloomy year.
2016 started with a memorable cold wave, peaking at -33.1°C, and with January averaging -10.3/-18.1 averages. Following a snowy, but less cold February, the year turned out to be rather unspectacular afterwards. September once again recorded a Dfb month, this being the fifth such reading this decade. Winter kickstarted in November with a fourth month below -3°C averages besides the three safe ones, before December had unusually high diurnals for the season. How many clear nights there were is difficult to measure though, given how little measurable sunshine it's capable of reaching in December.
2017 saw a moderate Dfc year. Although Luleå didn't go above 23.7°C all year and fell to -31.1°C once, on average the lack of warmth and the lack of general cold were evenly distributed, causing a rather low seasonal range of just 21.7°C. November and December were quite normal though, it was just that January-March in general were milder than expected. May averaging 9.8/1.1 was also rather low, especially for a decade like this in Scandinavia.
2018 was nowhere close to the 2015 readings, unlike the more cold-resistent southern parts of Scandinavia. The unique part about the year though, was that as many as five months just got past the 10°C isotherm and as a result had two months coverage as a Dfb, which is probably a first in Luleå's history. Elsewhere, as many as four months went below -7.3°C monthly means as a result of the delayed spring. In stark contrast to this, November remained above freezing for means and thus 7.5°C milder than March. Summer was the warmest so far this decade and it's going to take a lot for 2019 to beat a 24.5/15.2 average July for Luleå. It was also the sunniest year on record for the town, with 2,265 hours of sunshine, with 428 hours for July getting close to the previous record of 447 hours from 1973. May did beat the previous record however, coming close to having two months above 400 hours in the same year, which is Arizona-level stuff, although of course with lower percentages. Luleå is rather close to receiving midnight sun after all.
During the 2010's, Luleå has had rather interesting weather to say the least. I assume Babu will be interested in this and especially the rather high sunshine numbers and how often it actually is Dfb.
2010 was a very cold year for the location with a 0.9°C mean. February didn't rise above freezing at all, but January did, unlike areas way farther south. Even so, logically the averages were colder than lower Scandinavia. Summer was rather cool, with July being the exception, it being rather normal. In spite of this, Luleå was way cooler than the Baltic Sea coastal region in relation to the expected averages, Luleå being unaffected and not reaching 25°C all month of July. Even so, it did actually happen, in May! November and December were way below average and cold. December became the second month of the year that didn't go above freezing. Also, it ended up with five months below -6.3°C means and with lows below -11.4°C as well as the coldest autumn month of the decade so far in that year's November.
2011 continued the cold start to the winter, with January and February being below average, with the winter peaking in the latter month with -11.3/-20.1 averages. June saw a strong heat burst with a 30°C reading, which is about as warm as it gets for Luleå. July then saw very mild overnight lows and continued the sunny trend. Similar to the rest of Sweden, the autumn was rather mild. In Luleå's case it was also both rather rainy (September) and snowy (December). The low diurnals from the low-pressure in September resulted in the year ending up a Dfb.
2012 was another cold year for Luleå, although it didn't match the previous years' winters for averages. That being said, February saw a -34.5°C cold snap along the frozen bay, before March turned milder than usual and April saw the cold strike back. Summer was a bit of nothing. I recall visiting in between Umeå and there in July that year and it felt like an autumn day. At the end of summer, Luleå hadn't reached 23°C once and was consistently below average. A rainy autumn ultimately culminated in a cold December that was largely a snowout. At those temperatures, I'd be surprised if it wasn't solidly above 100 cm just for December alone. Nevertheless, the cover on the ground peaked at a mere 55 cm.
2013 was another largely no-show summer, although Luleå recorded a rather sensational coastal 27.3°C high in May. Ultimately, the mild nature of September ensured another Dfb without any months recording 20°C highs and the four warmest months peaking at a mere 24°C. The otherwise most notable feature of 2013 was that March was the coldest month, with -9°C means and that spring turned around rapidly from April to May.
2014 saw the first truly warm summer month of the decade and it was rather spectacular for its high coastal latitude, with July ending up at a remarkable 24.0/15.0 for averages. It also saw the warmest temperature of the decade with a 30.8°C reading. Aside from that, the most notable feature of the year was the extremely mild February for the location, with average highs remaining above freezing and the intensive cloud cover enabling lows to be as mild as -3°C, which is close to 10°C milder than usual. The end result was that February was just the fourth coldest month of the year and also that September in the wake of the warm summer remained above 10°C means, thus becoming Dfb for the third time in four years. Average lows remained above freezing for the full year, something very rare for the Swedish high-latitude coastline.
2015 was the warmest year of the decade with 4.5°C means and once more with lows above freezing. The year started with the strongest snowout of the decade, with 154 mm of precipitation in January for -4.8/-12.9 averages. The 100 cm snow cover I'm sure would've made 🖕🏿Mörön🖕🏿 feel like it was Hokkaido! In February this further expanded to 110 cm of snow on the ground. Spring started warm, but was then delayed. Summer also saw a lot of lag, rarely enough August was the warmest month with 20.0/11.3 averages. A rather stable September that didn't once go above 17.7°C kept means above the threshold to be Dfb for the fourth time in five years. Ultimately, December turned out to be a winter month after all, in contrast to lower Scandinavia's extended autumn, but it was still quite a bit above average. Unlike the then national sunshine records on Gotland, Luleå had a quite gloomy year.
2016 started with a memorable cold wave, peaking at -33.1°C, and with January averaging -10.3/-18.1 averages. Following a snowy, but less cold February, the year turned out to be rather unspectacular afterwards. September once again recorded a Dfb month, this being the fifth such reading this decade. Winter kickstarted in November with a fourth month below -3°C averages besides the three safe ones, before December had unusually high diurnals for the season. How many clear nights there were is difficult to measure though, given how little measurable sunshine it's capable of reaching in December.
2017 saw a moderate Dfc year. Although Luleå didn't go above 23.7°C all year and fell to -31.1°C once, on average the lack of warmth and the lack of general cold were evenly distributed, causing a rather low seasonal range of just 21.7°C. November and December were quite normal though, it was just that January-March in general were milder than expected. May averaging 9.8/1.1 was also rather low, especially for a decade like this in Scandinavia.
2018 was nowhere close to the 2015 readings, unlike the more cold-resistent southern parts of Scandinavia. The unique part about the year though, was that as many as five months just got past the 10°C isotherm and as a result had two months coverage as a Dfb, which is probably a first in Luleå's history. Elsewhere, as many as four months went below -7.3°C monthly means as a result of the delayed spring. In stark contrast to this, November remained above freezing for means and thus 7.5°C milder than March. Summer was the warmest so far this decade and it's going to take a lot for 2019 to beat a 24.5/15.2 average July for Luleå. It was also the sunniest year on record for the town, with 2,265 hours of sunshine, with 428 hours for July getting close to the previous record of 447 hours from 1973. May did beat the previous record however, coming close to having two months above 400 hours in the same year, which is Arizona-level stuff, although of course with lower percentages. Luleå is rather close to receiving midnight sun after all.
