Visiting local bars in Lowell is better when you know what the weather holds. These temperatures and rainfall averages can help you determine the best time for bar hopping. The hottest months are usually July and August with an average temp of 69°F, while the coldest months are January and February with an average of 31°F. The snowiest months in Lowell are January, February, March, and April, with each month seeing an average of 5 inches of snowfall.