Although weather is just one factor, it can really affect your travel plans, especially when you're planning an extended stay in Joniškėlis. The hottest months are usually July and August, with an average temperature of 17°C, while the coldest months are January and February, with an average of -2°C. The snowiest months in Joniškėlis are January, February, December and November, with each month seeing an average of 34 cm of snowfall.