I have the distinct feeling that spring in Stockholm this year has been rather reluctant to reach the 20°C threshold. However, I'm not sure if impatience is clouding my judgment. Because sometimes, it may actually affect how I feel about the weather. Or so I suggest...

I say "feel" because it's often just a feeling, not an exact number. And sometimes the numbers do not tell the whole story, either. Since I often focus on maximum (and minimum) temperatures, you can't really tell how the temperature varied throughout the day. For example; when it was much cooler for hours during the day, and then spiked shortly to 19°C, only to fall back again.

Later, when you look at the charts, you think, "Oh, 19°C - but that's pretty normal, and rather pleasant". However, as I said, it doesn't tell you for example, if it the afternoon was cool most of the afternoon.

This far...

Now, let's take a look at that 20°C threshold in Stockholm City:

May 2025

has been a mixed bag so far, with low and somewhat higher temperatures. In general, however, it has only reached 20°C about three times. At other times, it has been cold during the day when temperatures stayed below 10°C. This happened four times.

Although it has gotten warmer and the nights have been milder, the overall impression I have of this May is that the weather has been unstable. There hasn't been a period with longer mild or warm days.

While this isn't unusual, it's just my impression that the temperatures don't seem to rise above 20°C. It's a sort of reluctant weather type. Including the GFS outlook for Stockholm, you can see a temperature trend that seems to "avoid" the 20°C threshold.

Visually, it's springtime transitioning into early summer. Everything is green. I've noticed that the outdoor tulips have been very persistent this year. Some have been blooming for almost three or four weeks and are still going strong. This is mainly true for those that are not too exposed to the sun. It's fascinating to see them last for such a long time.

The heat in the east

The heat has been staying over West Russia instead. Arkhangelsk on the coast of the Northern Ice sea did during one day reach 29°C. Moscow has been warm too for over a week with temperatures between 25-29°C. (The trend there started around 21th of May) A stable high pressure area, lead very warm air to high latitudes over Russia all the way to the north coast.

On the other hand, we often got fronts that swooped down over Sweden or passed through with clouds. Speaking of clouds, Let me look at the hours of sunshine, which I haven't done in a while.

Here's a chart from May 25, 2025, showing the heat in the east reaching the northern shores of western Russia, with temperatures up to 30°C.

Consequently, North and Central Europe experienced cooler temperatures as fronts and clouds lingered for quite some time.

Moving away

The high-pressure area over northwest Russia will move away and weaken, allowing a new group of low-pressure areas and fronts to come in from the west. This will create a sort of highway into Scandinavia and upper middle Europe. This suggests that temperatures in Stockholm will remain below 20°C, sometimes dropping lower when it rains and the clouds remain dense.

Tralalala!

Summer can wait.

Sunshine hours • May 2025

Well when compared to previous years' May months, we are on the short side this time. Last year we had a daily average of almost record breaking 12.5 hours. In 2023 also 12,1 hours per day. And in May 2022 just 8.8 hours per day. Worse it got in 2021 with just 7 hours per day.

Now we are at 7.86 hours sunshine per day. So yeah, it is a bit on the low(er) side... The daily average of 7.9 hours corresponds to unstable weather, as you get more often cloudy periods.

Last year May 2024, was exceptional, because it was almost always super sunny: The curve went from an extremely poor April 2024 (3.8 hours) which was even less than March - straight up like a rocket to almost record levels with 12.5 hours sunshine per day.

Not the worst May

But as you can see in the chart, there are certainly poorer May months possible. Like in 1983, with only 6.5 hours daily sunshine.

Or the recent May 2021 with 7 hours per day. The temperatures in May 2021 also had trouble to reach 20°C, being on the reluctant side; just 4 such days were registered.

Perhaps I expect too much from May ? Probably yes. I seem to forget Stockholm is a city high up in the North. Getting a warm May month is not a standard. Despite the claims being in an "Era of Global burning" or whatever.

I do not know the lowest amount of sunshine for May in Stockholm. I am sure there are such months in existence - but I do not have any data on that.

May 2024 - Exceptionally warm

Here is the temperature chart from last year's May 2024; with its exceptional high amount of sunshine hours, resulting into high temperatures, acting more like a month during peak summer:

Ralf, you're Spoiled Weather Brat

Yeah, maybe I have gotten spoiled from much warmer months compared to the normal average. This May is more in line with normal temperatures, i would say. Perhaps a notch on the cooler side, at around 1° cooler than normal.

No big deal, really.

May 1991

Well that was a cold May. Well, the whole springtime into summer was a way too cool period lasting over several months; from Mid April until 1 July - it was almost constantly too cold. A shit year it was. Also on personal basis. I call it the "Great Depression". Albeit, also a time, in which my life reached a point that diverted from a negative path. It got to do with the fate of my mother. Somehow in the middle of that June, our fate / life paths separated from one another - and I started on my own path in life, much less influenced from the dark ghosts of the past.

So, ultimately it was a good thing - albeit it was a frikkin dark year.

When you look at the temperatures from May 1991, you see that there was not a single day reaching 20°C. You were lucky if it even reached 15°C.

So, there is that...

Here you see only the daily MEAN temperatures, no min or max