The winter season officially got underway at 8pm on Thursday in Stekenjokk, Västerbotten, following five consecutive days where the average daytime temperature was below 0C.
Five days of sub-zero weather is Sweden's official meteorological definition of winter, while five days of average daytime temperatures below 10C marks the start of autumn. Only once temperatures have climbed back above zero for a full seven days in a row, spring will have arrived.
Stekenjokk is the first of Sweden's official weather stations to enter official meteorological winter this year, although a section of the mountainous northwest have seen the mercury drop below zero for less than five days (marked in blue on the map below).
Across most of the country, autumn has already arrived, marked in yellow on the map, while green shows those areas where it has been meteorological autumn for at least five days in a row. The red section represents summer temperatures.
A map showing seasons across Sweden on September 27th. Image: SMHI
“It's been so cold that I dare to say winter is here,” SVT meterologist Per Stenborg said on Thursday afternoon, explaining that by that time, the current temperature of -2.2C meant there was too little time for any increase to affect the daytime average.
After five days of winter temperatures, the official first day of winter is recorded as the first of the five, so in the case of Stekenjokk, it will be September 23rd.
Sweden's method of measuring seasons means not only that it can be several seasons on the same day in different parts of the country, but that some locations skip an entire season.
READ ALSO: How to talk about the weather in Swedish