Planning for the weather is a good way to make your trip to Arraial do Cabo relaxing and enjoyable, especially when you’re splurging. The hottest months are usually February and March with an average temp of 78°F, while the coldest months are July and August with an average of 71°F. The rainiest months in Arraial do Cabo are November, December, January, and March, with each month seeing an average of 8 inches of rainfall.