Planning for the weather is a good way to make your trip to Negril relaxing and enjoyable, especially when you’re splurging. The hottest months are usually August and September with an average temp of 83°F, while the coldest months are February and January with an average of 79°F. The rainiest months in Negril are May, October, September, and August, with each month seeing an average of 8 inches of rainfall.