Temperatures

reached a minimum around 20.00 last night with 15.5°C. Since that time, it has been slowly rising all the way to now in order to reach 17-18°C - under an overcast sky. The reason for this mild night with feeling of summer, is the inflow of mild air within a low pressure area. In other words; it will not last.

On Sunday, strong fronts will swoop away the warm air... (Albeit already on Wednesday a strong high pressure area is expected over Sweden. I assume this will prevent cold air to move into Sweden from the north. The high pressure area acts like a blockage. For the time being.

Unusual mild is perhaps a too strong word

for this very mild morning. After all, we are still in September, and these mild phenomenas are within the parameters of what is "normal" in weather. Summer wasn't such a long time ago, so there are still plenty of warm airmasses over (southern) Europe, which at any time can move into our Northern region.

The normal minimum in Stockholm City for this time of the year is around 9°C.

1+3 Nov 2024

I think i remember in the beginning of November... (was it last year ? Yes, it was) When the temperature in the morning of 1 November 2024 hovered around 14°C, which felt very mild (and fantastic, like springtime !!). The morning after however, after a cold front passage, it was frosty with 3°C. (On the third morning, it was again, very mild with 13°C) and then it went down anew close to 1°C.

Let me dig out that event among the statistics....

A very strong flow of mild Atlantic air was transported from the mid Atlantic all the way to Southern Sweden. Stockholm was just within that boundary of warm, separating the much colder air 70 km north of the city.

A 10-12°C difference within 100 km separated wild and cold. See below... I thought that was very fascinating, because it doesn't really happen often that you encounter large differences in temperature within a small area.

The US has largely continental climate, while Sweden is mainly influenced by the large Atlantic, and to a lesser degree by the the Baltic sea, and the extremes are not as extreme like in the US sometimes.

last year's morning temperatures on 1 Nov 2024

Last 20°C day today ?

given that the temperatures in Stockholm City already approached 18°C, it isn't far off to think that it will reach 20°C during the day. With or without sunshine (it might clear up a little bit). And that is perhaps the very last summer-ish day of the year 2025...