This week’s weather is looking unstable and warm.

On Monday, it’s going to rain in southern Finland and by the evening in many other parts too. The Finnish Meteorological Institute’s weather map forecasts increasing rain chances for the Helsinki area in the evening. There could be some thunder as well.

Daytime highs are around 20 degrees Celsius and lows around 16.

Beginning on Tuesday, the temperatures are going to rise daily in the southern and central parts to over 20 degrees Celsius; the threshold for hot weather could be exceeded occasionally in some parts.

Occasional rain showers are possible throughout the week, especially in central, southern and eastern Finland.

In northern Finland, the weather is brighter most of the week. At the end of the week, the skies are becoming brighter in the southern parts too.

In the midst of all this talk about rain, there are some interesting details in the current weather patterns that at its best could turn around the forecast.

“The hot air mass is circling continuously near Finland,” Meteorologist Joanna Rinne says on weather service Foreca’s website. “Sometimes in southwestern parts, sometimes in southern parts and sometimes in western parts. The slightest change in the forecast may leave the situation looking totally different.”