If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in La Vega: The hottest months are usually September and August with an average temp of 62°F, while the coldest months are January and December with an average of 61°F. The rainiest months in La Vega are March, November, April, and October, with each month seeing an average of 12 inches of rainfall.