While warm days in the latter half of August are not especially rare, average temperatures at this time of year in the south are slightly below 20C and in Lapland, around 15C.
The most abrupt change in the weather has been seen in the regions of South Savo and Kainuu which were hit by heavy rains on Saturday. Parts of Savonlinna received close to 40mm of precipitation during a 12 hour period up to Saturday afternoon.
While most of the country can look forward to sunny skies throughout Sunday, western areas may see some cloud and showers.