San Juan is blessed with strong trade winds that keep mosquitoes at bay and somewhat lessen the sun’s vigor.
In the summer months (June to September), the city gets increasingly hot and humid, averaging in the high 80s. Rains come from late September through early November. San Juan isn’t hit as hard as the El Yunque area to the east, but gets a good amount of overflow.
December through May the weather is at its best – highs in the mid-80s, lows in the high 70s (sometimes those trade winds will have you reaching for a sweater at night) with little humidity.