This page covers biological activity — spawning windows and migration patterns — not legal harvest seasons. Bag limits, size limits, and closed seasons are a separate question with their own sourcing rail: see Regulations before you keep anything.
Snook spawn from roughly April/May through September/October, with documented spawning activity at Jupiter Inlet and Lake Worth Inlet on the Palm Beach County coast. In winter, snook go lethargic below about 65°F and retreat into low-salinity upper estuaries and canals as a thermal refuge — work them slow with artificials in shallow upper bays that time of year. In summer, live bait fished at night near dock lights and bridges on an outgoing tide, plus beach fishing near inlets during the spawn run, are the standard approach.
Tarpon migrate along the South Florida coast, with peak movement widely reported as May through July, though some fish are present nearly year-round. FWC's own gear restrictions at Boca Grande Pass (max 3 lines, no breakaway gear) apply specifically April through June — a regulatory signal of concentrated seasonal activity in that window. Tarpon are catch-and-release only in Florida; fish over 40 inches must stay in the water (see Regulations).
Permit hold offshore near structure and inshore over grass flats, sand, and in channels — South Florida's flats are specifically known as a permit fishery. Spawning occurs primarily in early summer and again in fall.
Mahi follow warm Gulf Stream water north each spring. Early arrivals show offshore in April; the season peaks May through July with the biggest, most consistent numbers; fish push farther offshore as summer heat sets in, and a second solid window opens in September–October.
Two different windows show up in the sources, and they answer different questions — don't conflate them. FWC's species profile notes sailfish move inshore to shallow water and spawn near the surface off southeast Florida in summer. Separately, the angler-facing "sailfish season" that Palm Beach/Broward/Miami charter culture runs on is a winter bite: south of Fort Pierce, that season is described as starting in November, with the Keys' prime window November–January and a second window April–early May. Sailfish tire easily and are treated as catch-and-release by angler convention — revive before releasing.
Black grouper, the dominant Atlantic-side reef grouper in South Florida, holds on reefs and drop-offs deeper than about 60 feet as adults and spawns during winter months. Gag grouper spawn January through May; juveniles use estuaries and seagrass before migrating offshore to reef structure as adults.
Mutton snapper spawn July–August around coastal structure. Yellowtail snapper spawn April–August, forming offshore aggregations, with activity dropping off in winter. Mangrove (gray) snapper around bridges and docks bite best from first light through mid-morning, after an active overnight feed.
Peacock bass are strictly a warm-water species: fingerlings die below 61°F and adults can't tolerate prolonged cold, which is exactly why Florida's population stays capped to Miami-Dade and Broward canals, occasionally reaching Palm Beach in mild winters. They're daytime-only feeders and don't bite at night.
In extreme south Florida, spawning can start as early as January, well ahead of statewide peak spawning (March–April) and far ahead of the Panhandle's May spawn. Winter (November–February) is a popular season here specifically because fish bed shallow. Bass activity also tracks the moon — most active roughly five days before to two days after the full moon.