Tarpon: water temperature and season

Spring run April to June, with resident fish all year. Anglrithm scores tarpon 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 tarpon. The score uses a working range of 74-87 °F, a fishing opinion rather than a tagged band, and its credit falls away above that range as well as below it.

Season

Best Apr to Jun, 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%
  • Water tempWell establishedkeeps 100%
  • LightReal, but localkeeps 100%
  • MoonSmall real effectkeeps 50%
  • SolunarPopular belief, not supportedkeeps 20%Labelled not supported: it stays visible, discounted, and is never promoted.
  • BarometerPopular belief, not supportedkeeps 20%Labelled not supported: it stays visible, discounted, and is never promoted.
  • 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.
  • 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.
  • Light: Dawn and dusk are well documented as movement and feeding windows for many inshore and coastal species, and the effect interacts with tide rather than standing alone. Viehman & Zydlewski 2017, PLOS ONE 12:e0176405.
  • Moon: Moonlight genuinely times spawning in many species through melatonin and clock genes, which is why aggregations key to the moon. For whether today is a good day, the measured effect is real but tiny, smaller than temperature and far smaller than where you fish. Ikegami et al. 2014, Marine Genomics 14:59-66. Shaw et al. 2021 found lunar effects significant but Cohen d below 0.20.
  • Solunar: The best-powered test of solunar tables found nothing. One angler, 361 trips and 1,355 hours, seven commercial solunar services, corrected for multiple testing, with 99 percent power to detect a medium effect: no relationship between any solunar value and catch rate. Just two results were significant, and both were negative, with trips inside predicted minor windows yielding 42.5 percent fewer fish per hour. Air temperature beat every solunar prediction. Quigley, Gonzalez Murcia & Kauwe 2023, SN Applied Sciences 5:162.
  • Barometer: A 30 hPa swing, which is about the biggest front of the year, is the same pressure change a fish feels by swimming down a foot. The direct feeding experiment on yellow perch found no significant influence, and thirteen years of angler data did not surface pressure trend as a meaningful predictor. It is also unidentifiable in principle from a catch log, because the barometer moves with the wind, the cloud and the temperature. VanderWeyst 2013, Bemidji State University. Shaw et al. 2021, PLOS ONE 16:e0257882.
  • Light wind: 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.

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

Tarpon are catch and release only in Florida. A tarpon over 40 inches stays in the water unless you hold a tarpon tag.

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

From the research programs

  • Of 200 acoustically tagged tarpon, tracking revealed two groups: one migrating up the Southeast Atlantic coast, one heading into the Gulf. ScienceDaily, 2023
  • Many tarpon gather in the Florida Keys each spring to spawn, and individuals often repeat the same migration route yearly. ScienceDaily, 2023
  • Keys-tagged tarpon regularly migrate north as far as Georgia and the Carolinas. Bonefish & Tarpon Trust, 2022
  • Boca Grande Pass release mortality was estimated at 7.3 to 17.1 percent, and every confirmed dead tarpon was killed by sharks. FWC, 2004
  • Leaving out shark kills, Boca Grande tarpon release mortality fell to about 4.9 percent. FWC, 2004
  • Preliminary Tampa Bay tracking found roughly 90 percent of released tarpon survived. FWC, 2006
  • Florida rules require tarpon over 40 inches to stay in the water during release. Bonefish & Tarpon Trust, no date
  • Juvenile tarpon 12 inches and under rely on tidal mangrove creeks and backcountry waters; Charlotte Harbor and Indian River Lagoon are focus regions. Bonefish & Tarpon Trust, 2021
  • The 2026 cold snap caused low to moderate deaths of juvenile and subadult tarpon in Indian River Lagoon and Charlotte Harbor. Bonefish & Tarpon Trust, 2026

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

The studies

  • Juvenile tarpon in Texas bays are most likely in fresh to brackish water below about 20 PSU and at 20 to 27 C.

    Texas bays, northern Gulf (out of region) (outside South Florida) · model · full text read

    Stephens et al. 2024

  • Young tarpon tolerate salinity from near fresh to over 40 ppt and water up to at least 36 C.

    Review, flats fisheries (incl. Florida) · review · full text read

    Danylchuk et al. 2023

  • Along Florida's Gulf coast, cobia and many sharks move north in spring and south in fall; tarpon head north later, in summer.

    Florida Gulf coast · field · full text read

    Friess et al. 2021

  • During two Category 5 hurricanes, tagged nearshore fish shifted briefly toward deeper water, but most stayed in the bay for months.

    US Virgin Islands (out of region) (outside South Florida) · field · full text read

    Matley et al. 2019

  • Big migratory tarpon arrive in South Florida in late April and leave by late June, with a smaller fall push.

    Florida Keys; Florida Bay; Everglades; SW Florida · field · full text read

    Hammerschlag et al. 2012

  • The 2010 freeze hit snook, tarpon and ladyfish hardest in Everglades waters; redfish survived better.

    Everglades National Park, Florida Bay, Flamingo · agency · agency document

    National Park Service, Everglades National Park 2010

  • In January 2010 Sanibel's Tarpon Bay lost ladyfish, tarpon, mullet and gag to cold.

    Sanibel, Tarpon Bay, SW Florida · field · agency document

    Sanibel-Captiva Conservation Foundation Marine Laboratory 2010

  • Shallow coastal ponds ringed by salt marsh and overhanging mangroves are nurseries for juvenile snook, with juvenile tarpon nearby.

    Charlotte Harbor (Cape Haze peninsula), SW Florida · field · full text re-read Oct 16, 2026

    Saari et al. 2025

The whole evidence library

Entries read in full text or published by an agency. Entries read only in their abstract are listed on the science page with their numbers withheld.

Research cited: Bonefish & Tarpon Trust. Cited, not endorsed.

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.