Thunderstorms and heavy rain are set to affect large parts of Finland at the start of the week as an unstable weather front moves across the country. Forecasters expect the most active storms on Monday and Tuesday before high pressure brings calmer conditions from the middle of the week.
Foreca said the strongest thunderstorms are expected in eastern Finland and Kainuu on Monday before shifting towards northern Finland on Tuesday.
Meteorologist Kristian Roine said conditions will begin to improve from Wednesday as a high-pressure system moves in from the southwest.
The change follows a wet month across much of Finland. Rainfall totals have exceeded seasonal averages in several locations, with Nokia recording 181.3 millimetres of rain by 26 July. That figure is around two and a half times the normal rainfall for the month, and further showers early next week could push the total close to 200 millimetres.
Heavy downpours have already caused local flooding during July. One intense rainstorm swept across Helsinki earlier this month, leaving streets under water after a short period of intense rainfall.
The weather front moving across the country will also keep temperatures below typical late July levels during the first part of the week. Daytime highs are expected to remain around 20°C in many areas while rain and cloud cover persist.
Forecasters said rainfall will become more scattered by Wednesday as the high-pressure system strengthens. Sunshine is expected to increase across the country, with only isolated afternoon showers remaining.
Temperatures will also begin to recover once the rain clears. Highs are forecast to reach around 20°C on Wednesday before rising to about 25°C on Thursday. Widespread temperatures above 25°C are expected on Friday.
The return of warmer air follows several days of cooler conditions across Finland. During the weekend, temperatures exceeded 20°C mainly in eastern Finland. Tohmajärvi recorded 22.5°C on Saturday, with the same weather station reaching 23°C by mid-afternoon on Sunday.
Despite the wet conditions, Finland has already recorded 11 days of temperatures above 25°C during July. The highest number of hot days has been observed at Turku Artukainen and Lepaa in Hattula, where temperatures reached at least 25°C on seven separate days.
Foreca said the overall average temperature for July has remained close to the long-term average despite frequent rainfall and periods of cooler weather.
HT