Overview: Fort Pierce, FLFort Pierce, FL (United States of America) in general has a tropical climate. Temperatures during the day are in the range from 24 °C (74 °F) in January to 33 °C (91 °F) in August. Temperatures during the night go from 11 °C (53 °F) in January to 23 °C (73 °F) in August. The driest month is April with just 6 days of rain, on the contrary, the month when it rains the most is August with 17 days of rain.