Tarpon Springs is at its best from November to April, when the Gulf Coast humidity is manageable and the temperature sits between 18 and 26 degrees. The winter months also bring manatees into the warmer river and bayou waters, which is a genuine spectacle.
January 6th — Epiphany — is the single best day to visit if you can plan around it. The Greek Orthodox Epiphany ceremony at Spring Bayou is one of the most vivid cultural events in Florida, drawing thousands of spectators. Book accommodation well ahead.
Summer (June to September) is hot and humid, with regular afternoon thunderstorms. The Sponge Docks are still busy but less pleasant. Mosquitoes are active in the mangrove areas.
The tourist traffic peaks on winter weekends when day-trippers arrive from Tampa and St Petersburg. A weekday visit in January or February gives you the same good weather with a fraction of the crowds.