Mahi: water temperature and season

Late spring and early summer, blue water and weedlines. Anglrithm scores mahi at offshore spots on the Atlantic side and in the Keys. This page sets out what that score weighs and the cited studies behind it.

Water temperature

Evidence tier Well established

The tagged band for mahi is 77-84 °F, with most time at 80-82 °F. Tagged mahi spent 95% of their time in 25-29 °C (77-84 °F) and preferred 27-28 °C. Schlenker et al. 2021, Frontiers in Marine Science 8:626082 (evidence: strong).

The band works in both directions. Fish feed along a dome, rising to an optimum and falling away past it, so water above the band counts against an hour just as water below it does. Outside the band, either way, no hour rates GOOD in the score, and an hour loses more the further out the water is.

Season

Best Apr to Jul, 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%
WindSmall real effectkeeps 50%
Wind directionSmall real effectkeeps 50%
SeasSmall real effectkeeps 50%
Water tempWell establishedkeeps 100%
SkyReal, but localkeeps 100%
CurrentSmall real effectkeeps 50%
LightReal, but localkeeps 100%
Wind vs currentSmall real effectkeeps 50%

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.
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.
Seas: Sea state mostly decides whether the trip happens and whether you can fish it well. Treat a sea-state pattern in your own log as a fact about your fishing, not about the fish. No direct angling-scale study found; labelled from mechanism.
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.
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.
Current: No study we found ties a current speed or direction to catch for any fish in this app. Current decides whether you can hold a bait where you want it and how a drift sets up: off Southeast Florida the Gulf Stream runs fast close to the coast, and deep-drop boats stay under power to hold position. Treat a current pattern as a fact about your fishing more than about the fish. Davis, Cudney & Blankinship 2017, Bulletin of Marine Science 93:539-555. Lerner et al. 2013, Transactions of the American Fisheries Society 142:95-104.
Wind vs current: Wind blowing against the current stands the seas up: shorter, steeper and more likely to break than the same wind over slack water, which decides how a drift sets up and how long a day stays fishable. That is physics about the water, not evidence about the fish; no study we found ties it to catch. U.S. Coast Pilot 4, Chapter 3 (opposing wind and current on the Gulf Stream: sharply higher, steeper seas that can break; mechanism only). No catch study found.

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.

From the research programs

About 68 percent of tagged dolphin were released off Florida; most moved north, reaching the Mid-Atlantic Bight in about 44 days on average. North Carolina Sea Grant, 2022
The fastest Florida to North Carolina straight-line trip took 7 days; 71 percent of recaptures came within 40 days. North Carolina Sea Grant, 2022
Dolphin movement along the east Florida shelf averaged about 22 nm a day in 2020, against about 48 nm in 2018. Dolphinfish Research Program, 2020
June Keys releases sometimes lingered near the release area for three to five days instead of racing up the Straits. Dolphinfish Research Program, 2019
Anglers tagged more than 800 dolphin in June 2016, most of them released off South Florida and the Keys, and 21 tag recoveries were reported that month. AFTCO, 2016
Fall to early spring recoveries off Caribbean islands suggest East Coast dolphin spend winter there. AFTCO, 2016
Dolphin can grow up to about an inch per week; a 14-inch fish is roughly 3 to 4 months old. Dolphinfish Research Program, 2022
The Florida Straits zone accounts for about 40 percent of 39,153 program tag deployments from 2002 to 2025. Dolphinfish Research Program, 2025

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

Spring larval tuna and mahi numbers in the central Gulf rose and fell with how far north the Loop Current reached.
northern Gulf of Mexico (outside South Florida) · field · full text read
Lindo-Atichati et al. 2012
Mahi, wahoo and yellowfin patches match surface temperature patches, but swordfish patches match temperature at 200 m.
Gulf of Mexico (outside South Florida) · field · full text read
Kleisner et al. 2010
Per ocean boat trip, east Florida dolphin catch peaks May-June; wahoo and blackfin peak September-December.
Florida Atlantic coast (MRIP South Atlantic Florida, excludes Monroe County) · agency · agency document
NOAA Fisheries Marine Recreational Information Program 2025
In Florida's Gulf plus Keys domain, dolphin catch per trip peaks July-August and blackfin and wahoo peak September-October.
Florida Gulf coast including Monroe County (Keys) as one MRIP domain · agency · agency document
NOAA Fisheries Marine Recreational Information Program 2025
Most Florida-tagged dolphinfish are recaptured off Florida within about a week; others reach the Carolinas in about a month.
East Florida to Mid-Atlantic; Bahamas; Caribbean (outside South Florida) · agency · agency document
Merten 2020

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: Dolphinfish Research Program (Beyond Our Shores). 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.