Weather is only one factor, but it can really affect your travel plans, especially when you're planning an extended stay in Holyoke. The hottest months are usually July and August, with an average temperature of 18°C, while the coldest months are January and February, with an average of -8°C. The snowiest months in Holyoke are April, March, January and December, with each month seeing an average of 24 cm of snowfall.