Sunday was Finland's warmest day in the last week of September in the past half-century.
The highest temperature, 23.5 degrees Celsius, was measured in the southwestern town of Kokemäki, between Tampere and Rauma.
“That’s the highest reading in the last week of September in the past half-century,” says Yle meteorologist Anne Borgström.
An exceptionally warm air current from the southeast has kept days and nights unseasonably mild in southern and central Finland since last week. Meanwhile the north of the country has been shivering with rain and temperatures in the single digits.
Warm dry weather is set to continue in much of Finland this coming week, she says Borgström.
The mercury may again pass the 20-degree mark on Monday, and it will remain warmer than usual after that as well. Next week looks dry through most of Finland, says Borgström.
Hot September of '68
Sunday was cooler on the mid-to-upper west coast and in Northern Ostrobothnia due to very heavy stratus clouds. Those low-level clouds will burn off on Monday, bringing warmer weather there as well, she predicts.
Temperatures were also brought down in Northern Ostrobothnia and Lapland by rain on Sunday. The band of precipitation will move northward and diminish on Monday, allowing the warmer air to gradually seep into Lapland as well.
The all-time heat record for September was set not far from Kokemäki, in the coastal town of Rauma. On 6 September 1968, the thermometer read 28.8 degrees.
Finland’s latest ever recorded ‘hot’ day – defined here as over 25 degrees – was 17 September 1947, when a reading of 25.2 degrees was reported in Tampere.