Planning for the weather is a good way to make your trip to St. Anns relaxing and enjoyable, especially when you’re splurging. The hottest months are usually September and October with an average temp of 81°F, while the coldest months are January and February with an average of 78°F. The rainiest months in St. Anns are October, November, August, and July, with each month seeing an average of 8 inches of rainfall.