Weather is only one factor, but it can really affect your travel plans, especially if you are planning a longer stay in Dayton. The hottest months are usually July and August, with an average temperature of 22°C, while the coldest months are January and February, with an average of -3°C. The snowiest months in Dayton are January, February, March and April, with each month seeing an average of 13 cm of snowfall.