If you're looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Litchfield by the Sea: The hottest months are usually July and August, with an average temperature of 26°C, while the coldest months are January and February, with an average of 12°C. The rainiest months in Litchfield by the Sea are August, July, September and June, with each month seeing an average of 194 mm of rainfall.