The warm season lasts for 3.0 months, from June 11 to September 12, with an average daily high temperature above 65°F. The hottest month of the year in Bristol is July, with an average high of 69°F and low of 56°F.

The cool season lasts for 4.0 months, from November 18 to March 17, with an average daily high temperature below 50°F. The coldest month of the year in Bristol is February, with an average low of 37°F and high of 46°F.