If you're looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Rockport: The hottest months are usually August and July, with an average temperature of 12°C, while the coldest months are December and February, with an average of -3°C. The rainiest months in Rockport are November, January, December and October, with each month seeing an average of 278 mm of rainfall.