Fall in Marathon

Fall is one of the most enjoyable times to visit Marathon in the Florida Keys. From September through November, the island settles into a calmer, more laid-back rhythm while still offering warm temperatures, stunning waters, and a wide range of seasonal activities. With fewer crowds and ideal weather conditions, fall is perfect for travelers seeking a relaxed yet adventure-filled island experience.

During the fall, Marathon enjoys daytime temperatures in the mid- to upper-80s, gradually cooling into the upper 70s as the season progresses. Nights are comfortable, typically ranging from the low 70s to mid-70s, making outdoor evenings especially pleasant. Humidity levels decrease from about 75% in early fall to near 68% by November, allowing for more comfortable days spent exploring the islands or participating in outdoor activities. Rainfall is more common in early fall, but showers are generally brief and quickly give way to sunshine, while late fall is notably drier. Water temperatures remain invitingly warm, averaging 78–85°F, perfect for swimming, snorkeling, diving, or simply enjoying a leisurely day on the water.

Fall is also a fantastic season for outdoor adventures. The calmer seas and clear waters provide excellent conditions for snorkeling and diving, offering vibrant views of coral reefs and marine life. Fishing enthusiasts can take advantage of fewer crowds and abundant offshore and reef fishing opportunities, while kayakers and paddleboarders can enjoy peaceful explorations of mangrove tunnels and backcountry flats. On land, visitors can bike along the scenic Overseas Heritage Trail, stroll through the shaded trails of Crane Point Hammock, or relax at Sombrero Beach.

Marathon also hosts a variety of seasonal events and activities in the fall. Visitors can experience family-friendly festivals, community gatherings, fishing tournaments, and eco-focused wildlife tours. Highlights include the Fall Family Festival at Marathon Community Park, Crane Point’s seasonal fall fun activities, and popular fishing tournaments like the Wahoo Fishing Showdown. Bird watchers can also enjoy migrating species at local hawkwatch sites, adding a unique nature-focused dimension to a fall visit.

Evenings in Marathon during the fall are perfect for unwinding. Waterfront dining, live music, sunset cruises, and casual strolls along the docks offer a chance to soak in the island ambiance. Fall is also an excellent time for couples, families, or solo travelers to enjoy a quieter vacation, with easier access to attractions, fewer crowds, and more flexible booking options.

Whether you’re seeking water adventures, relaxation, or a chance to enjoy local events, fall in Marathon delivers a perfect blend of warmth, tranquility, and seasonal charm. With its inviting weather, warm waters, and peaceful island pace, fall provides an ideal opportunity to experience the Florida Keys at their most welcoming and serene.

Average Fall Temps & Climate

Sept:  High 88°F / Low 78°F

Oct:  High 85°F / Low 75°F

Nov:  High 82°F / Low 70°F

Humidity Index

Across the fall season in Marathon average humidity typically ranges between 68% and 77%. Early fall leans more tropical and humid, while conditions gradually become drier and more comfortable as the season progresses. Ocean breezes help keep the air pleasant throughout the day, and by late fall, humidity levels are noticeably lower; making outdoor activities, boating, and evenings by the water especially enjoyable!

Rainfall

For the fall season as a whole Marathon averages roughly 8–12 inches  of total rainfall, with most of it occurring early in the season.

Rainfall is highest in early fall and steadily decreases as the months progress. Showers are typically short, passing tropical rains, often followed by sunshine rather than all-day storms. By late fall, conditions are noticeably drier and more stable, making it one of the most pleasant times to visit the Florida Keys

Water Temperatures

Sept:  ~84–85°F

Oct:  ~82-83°F

Nov:  ~78-80°F

Fall in Marathon offers slightly different conditions while remaining warm and inviting!