The summer arrived suddenly

Above is a screenshot from the Finnish weather service today at 12:40 showing the temperature curve for the last 24 hours at the airport nearby.
+25.1 C or 77.2 F !
We even had a thunderstorm this morning which is very unusual in May.
The bad news is that this pre-summer will last only for a week. Then we are back to the normal crappy 12 - 15 C again.