Many areas of the country will reach 25 degrees by the end of the week.File photo of Helsinki's Esplanade Park. Image: Henrietta Hassinen / YleYle NewsSTT16:19Finland is set to get more summer-like weather at the beginning of the week, according to the Finnish Meteorological Institute (FMI).It said south-eastern areas will likely first break the country's 'hot weather' threshold — 25 degrees Celsius — as temperatures heat up.FMI's forecast said temperatures could rise to 20 degrees in many areas by Monday, including as far north as Oulu.Tuesday and Wednesday will likely see temperatures above 20 degrees in southern and eastern areas.Tuesday will also see rain and thunderstorms in southern and western areas, according to the forecast.Thunderstorms are also possible in eastern areas on Wednesday.Weather service Foreca expects that the rain will mostly clear towards the end of the week and warm temperatures will cover a wide area of Finland over the weekend.Starting on Friday, many areas will see temperatures above 25 degrees.