Planning for the weather is an important factor for making your trip to Busto Arsizio a success, especially when you’re splurging. The hottest months are usually July and August, with an average temperature of 22°C, while the coldest months are January and December, with an average of 5°C. The rainiest months in Busto Arsizio are November, October, May and August, with each month seeing an average of 194 mm of rainfall.