Permit: water temperature and season

Spawns on Keys reefs in spring and summer; on the flats all year. Anglrithm scores permit at inshore and reef spots, on the Atlantic, in the Keys and on the southwest Gulf coast. This page sets out what that score weighs and the cited studies behind it.

Water temperature

Evidence tier Well established

No tagging study gives a surface temperature band for permit. The score uses a working range of 74-88 °F, a fishing opinion rather than a tagged band, and its credit falls away above that range as well as below it.

Season

Best Mar to May, by the score's season weight.

The score's season weight by month, from the studies cited in the species profile; the outlined months are at 90% of its peak or better.

What the score weighs

  • SeasonWell establishedkeeps 100%
  • TideReal, but localkeeps 100%
  • WindSmall real effectkeeps 50%
  • SkyReal, but localkeeps 100%
  • LightReal, but localkeeps 100%
  • Water tempWell establishedkeeps 100%
  • Light windReal, but localkeeps 100%
Why each tier
  • Season: Season is the strongest single predictor in most recreational datasets, because it carries water temperature, migration and spawning together. Shaw et al. 2021, PLOS ONE 16:e0257882.
  • Tide: Tide moves fish through cuts and over structure, and the effect can be strong at a particular spot. It is not a species-wide rule: the published work finds the pattern flips by species, site and season, and one high-velocity channel study found no link to current speed at all. Trust it where you fish; do not trust it as a fact about the fish. Becker et al. 2016, Estuaries and Coasts 39:1199. Milardi et al. 2018, ECSS. Viehman & Zydlewski 2017, PLOS ONE 12:e0176405.
  • Wind: Wind has a measurable effect on fish movement, apparently through dissolved oxygen, but it is small. The larger effect in any personal log is on you: wind decides where you can fish and whether you go at all, so a wind pattern in your own data is at least as likely to be about your choices as about the fish. Milardi et al. 2019, Aquatic Ecology 53:251-263. Shaw et al. 2021, PLOS ONE 16:e0257882.
  • Sky: Sun, cloud and rain change what you can see, not what the fish do. Sight fishing on the flats, and spotting fish, birds and weed offshore, depend on light getting into the water and on the glare coming off it, and how much sky and sun the surface throws back at you changes with the cloud, the wind and the height of the sun. On the flats with the sun up, light wind lets you see into the water, so for bonefish, permit, tarpon and redfish at inshore spots the score counts it in the hour's favour, fully at 4 mph or less and fading out by 7 mph; a glassy flat also shows you to the fish, so it is a local call, not a rule about the fish. This is about the angler, so trust it where you sight-fish. Local knowledge, Joe, October 6, 2026 (cloud, rain and sun) and October 14, 2026 (light wind at 4 mph or less). Santos et al. 2017, PLOS ONE 12:e0184776 (South Florida bonefishing is largely a sight-based fishery). Mobley 1999, Applied Optics 38:7442-7455. Cortese & Reimchen 2023, Biological Journal of the Linnean Society 138:132-140.
  • Water temp: Fish are ectotherms, so appetite and digestion track water temperature along a dome: rising to an optimum, then falling away again. Warmer is not simply better. Snook energy demand roughly tripled from 15 to 25 C, and they were more likely to have empty stomachs when the water ran hot. Volkoff & Ronnestad 2020, Temperature 7:307-320. White et al. 2025, Marine and Coastal Fisheries 17:vtaf031, doi:10.1093/mcfafs/vtaf031.

Each factor's weight is multiplied by its evidence tier: well established and real but local keep all of it, a small real effect keeps half, and a popular belief that is not supported keeps a fifth. Guidance from the studies sits beside the score, never in it.

Rules and depth

Inside the Special Permit Zone (Cape Florida south through the Keys): no harvest or possession April through July, then 22 in fork length minimum, 1 per person and 2 per boat. North of Cape Florida: 11-22 in fork length with one over 22 in, 2 per person. Western Dry Rocks off Key West is closed to all fishing Apr 1 to Jul 31. Catch and release is open.

Seasons, sizes and bag limits change: check the FWC saltwater regulations before you keep a fish.

From the research programs

  • Tracking showed Keys permit reach reef and wreck spawning sites in April, so FWC added April to the May to July harvest closure in 2018. SECOORA FACT Network, 2018
  • Permit residency at a key spawning site was already high in March, before current April to July protections start. FIU, 2023
  • Keys permit residency peaks in spring and summer and drops sharply in late fall, hinting many leave the region. FIU, 2023
  • Permit showed the strongest site fidelity to artificial reefs; seagrass flats within roughly 5 nm of spawning sites may be key feeding grounds. FIU, 2023
  • Permit presence at a natural reef spawning site climbed in the days before the full moon, a likely spawning cue. FIU, 2023
  • At Western Dry Rocks, sharks ate about 39 percent of hooked permit before anglers could land them. Bonefish & Tarpon Trust, 2019
  • Western Dry Rocks has been closed to all fishing April through July since 2021 to protect spawning permit. Bonefish & Tarpon Trust, 2022
  • Because of shark losses, BTT considers catch and release at permit spawning sites during spawning season unsustainable. Bonefish & Tarpon Trust, 2022

Findings in our own words from the programs linked, area and season only; cited, not endorsed. None of these lines is in the score.

Where it is scored

Today's score at any of them is free with an account; every fish has a page like this one.

Display only, not for navigation. Every figure here names its source; check the NWS marine forecast and the posted rules before you leave the dock.