Every day we analyze satellite sea surface temperature imagery, chlorophyll and bait productivity data, surface current charts, and live NOAA marine forecasts to produce this report. The goal is to give you the clearest possible picture of what’s happening on the water before you book a trip or leave the dock.

Conditions move fast in the Keys. Currents shift, bait schools move, and thermal breaks appear and disappear overnight. A report from two days ago isn’t worth much. We try to update this report daily to make sure you have the most up to date info.

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How to read this report

Sea surface temperature (SST): Warmer water along the reef corridor (76–80°F) keeps reef fish active and feeding. Cold intrusions from the Gulf side can slow shallow-water species like tarpon early in the morning.
Chlorophyll / bait productivity: High chlorophyll readings along the reef line mean bait is stacked. This often means yellowtail, mangrove snapper, cobia and others are close behind.
Surface currents: Moderate Gulf Stream flow past the 408 Hump and Marathon West Hump creates ideal conditions for mahi, blackfin tuna, and wahoo. Slack current along the reef is better for anchoring and chumming.
Wind and seas: Under 15 knots and seas under 3 feet puts all our trips in play. Anything above that and we focus on protected reef and backcountry options.

Upcoming Fishing Conditions

6/20/2026

Overview

Marathon Fishing Prediction — Saturday, June 20, 2026

Overall Fishing Grade: 80/100 (Very Good) — Calm seas and a close, energized Gulf Stream edge stack up with a productive reef line for a strong offshore-and-reef day.

Conditions Snapshot (peak hours 6 AM – 6 PM EDT)

Sunrise 6:35 AM / Sunset 8:16 PM
Wind: SE near 10 kt early, easing to 5–10 kt and becoming variable — light all day.
Seas: Hawk Channel 1–2 ft subsiding to ~1 ft; offshore Straits ~2 ft subsiding to 1–2 ft. Smooth to light chop.
Water temp: Reef/nearshore ~86–89°F (warm); clean bluewater offshore ~83–84°F.
Tides (Vaca Cut): High 7:54 AM (0.6 ft) / Low 11:00 AM (0.4 ft) / High 5:49 PM (0.8 ft) / Low 11:47 PM (0.1 ft). Modest daytime range — neap-leaning.
Moon: Waxing crescent ~37%, building toward First Quarter Sunday.
Barometer: ~30.07 in, steady to slightly rising — stable.
Solunar: Average day; best practical windows ride the tide changes (morning high transition and the late-afternoon build).

Why This Grade

Two in-season, genuinely accessible buckets carry the day. Offshore, the blue water starts close — the Gulf Stream edge sits roughly 13 NM southeast of Marathon with good current energy along it, and calm seas put both the troll zone and the deeper humps in easy reach. On the reef, a strong chlorophyll-and-bait band is set up right along the reef line where the green inshore water meets the clean blue, which is exactly where the snapper bite concentrates. What holds the grade out of the mid-80s is a weak daytime tide — there’s less moving water to stretch a chum slick or fire up the flats — along with very warm shallow water that softens the backcountry and a slight afternoon thunderstorm risk that could interrupt the better midday window. Fish the tide-change windows and the low-light edges of the day and this is a Very Good day.

Zone-by-Zone Game Plan

Reef & Structure (~30–90 ft): The day’s anchor. Set up up-current of the reef line and build a steady chum slick for yellowtail and mangrove right on the green-to-blue edge; drop on deeper ledges and hard bottom for mutton and grouper. Calm seas make anchoring and boat control easy — lean on the tide-change windows since the daytime current is light.
Backcountry & Bridges: The softer bucket today. Warm shallow water and a weak daytime tide keep the flats honest — work first light and the late-day cool-down for resident tarpon and snook around bridges and cuts, with a permit or bonefish shot on the cleaner moving water near the tide changes.
Offshore: The blue water is close — a short run reaches the edge and good current energy. Work weed lines and frigate birds for mahi, and the edges of moving water at the deeper humps for blackfin. The calmer it lays down, the more ground you can cover.

Recent Local Catch Signal

Honest read: light fresh first-hand signal today — no captain dock screenshots in this run. Public reports continue to point to active summer mahi offshore and a productive reef-snapper bite (yellowtail and mangrove), with tarpon transitioning from peak migration to resident fish around the bridges. Treat the reef and offshore strength as season-and-conditions-driven rather than confirmed by today’s dock photos.

Species Forecast (all 13, ranked)

Species	Score	Technique	Location	Notes
Mahi-mahi	84	Troll weed lines / run-and-gun birds	Offshore edge, ~13 NM SE	Blue water starts close — a short run reaches the troll zone; the calmer it lays down, the more ground you cover.
Yellowtail snapper	82	Anchor & chum, light fluoro	Reef line, 40–70 ft	Best right where the green water meets the clean — long fluoro leaders earn more on a weak tide.
Mangrove snapper	79	Live bait tight to structure	Reef & bridge shadows	The better window is the low-light edges of the day as fish move up to feed.
Blackfin tuna	73	Jigs / live bait on the edge	Deeper humps & edge	Calm seas put the humps in reach — watch for bait pods on moving water.
Mutton snapper	68	Bottom rigs on the change	Deeper structure/rubble	Cleaner windows are the slack-to-moving transitions given the light daytime current.
Grouper (OPEN!)	62	Drop on hard bottom/ledges	Reef structure, 60–90 ft	Easy seas make boat control simple — lean on the morning before the sun climbs.
Permit	62	Sight-cast crab/fly	Flats & wrecks	Light wind helps the sight-fishing, but hunt the cleaner moving water near the tide changes.
Tarpon	58	Live bait / fly at the bridges	Bridges & cuts	Resident fish are the play — first light and the late cool-down beat the hot midday water. (Catch & release.)
King/Spanish mackerel	56	Fast retrieve, wire leader	Reef edge	Run the bait band on the reef edge and watch for flash on the surface.
Bonefish	53	Sight-cast shrimp/fly	Flats	Hot shallow water pushes fish to cooler edges — work the dawn window before the flats heat up. (Catch & release.)
Snook	52	Structure & bridge shadows	Backcountry/bridges	Low-light edges are the better bet on a summer pattern. (Catch & release.)
Wahoo	42	High-speed troll	Deeper offshore edge	More of a bycatch shot this time of year if you target the edge.
Sailfish	30	Incidental on the troll	Offshore	Off their prime season — treat any shot as a bonus. (Catch & release.)

Best Bite Windows (6 AM – 6 PM focus)

Dawn–8:30 AM: First light crossed with the 7:54 AM high transition — coolest water, best flats and early reef window.
10:30 AM–12:30 PM: Midday solunar minor near moon transit; reef chum bite as the outgoing settles, and prime offshore trolling once you’re at the edge.
4:30–6:30 PM: The building 5:49 PM high plus golden hour — strong second window for reef and a late flats look (watch for storm buildups).

Safety & Notes

No Small Craft Advisory. Slight chance of showers and thunderstorms — watch the afternoon buildups, especially offshore, and keep a plan to duck in.
Otherwise light winds and easy seas. Summer sun is intense — hydrate and cover up.

Links & Deals

#MarathonFishing #FloridaKeysFishing #FishingForecast #MahiMahi #YellowtailSnapper #CaptainHooks #FloridaKeys #OffshoreFishing #ReefFishing #FishingReport #KeysFishing #SaltwaterFishing

What to Expect When Fishing in Marathon, FL

Marathon sits at the heart of the Florida Keys, with easy access to the Atlantic reef tract to the south and Florida Bay to the north. That geography gives anglers access to three completely different fisheries within a short run of the dock. Try offshore bluewater, nearshore reef and wreck, and shallow backcountry flats.

Offshore fishing

The Gulf Stream runs close to the Keys year-round, pushing warm, clean bluewater within 15–20 miles of Marathon. Offshore structure like the 408 Hump and Marathon West Hump concentrate baitfish and attract pelagics in numbers that few places on the East Coast can match. Mahi-mahi are the bread-and-butter species spring through summer, with blackfin tuna and wahoo filling the box on the right day.

Reef and wreck fishing

The Florida Keys reef tract is one of the most productive fishing grounds in North America. Yellowtail snapper and mangrove snapper are on the reef virtually every day of the year. Mutton snapper and cobia show up in numbers during spring. Expect action from grouper (when in season), amberjack, cero mackerel, and barracuda.

Backcountry and flats fishing

Florida Bay and the grass flats north of Marathon are some of the best tarpon and bonefish water in the world. Tarpon migrate through the Keys from April through July in serious numbers. Permit, snook, and redfish round out the backcountry offering.

Seasonal fishing guide for Marathon, FL

Winter (Dec–Feb): Yellowtail and mangrove snapper fire up in cooler water. Sailfish peak offshore. Calm weather windows make for excellent bottom fishing days.
Spring (Mar–May): The best all-around season. Mahi arrive in force by March. Cobia move through the reef. Tarpon migration kicks off in April.
Summer (Jun–Aug): Mahi, tuna, and wahoo offshore. Consistent reef fishing. Morning trips are the move before afternoon thunderstorms build.
Fall (Sep–Nov): Kingfish move in. Reef fishing stays strong. Cooler temps and lighter crowds make fall an underrated time to fish the Keys.

Bait, tackle, and trip planning

Our Marathon bait and tackle shop carries fresh, live, and frozen bait along with everything you need for a day on the water. For a fully guided experience, our Marathon fishing charters cover all three fisheries. Also fishing out of Big Pine Key if that puts you closer to the action.

Marathon • Big
Pine Key • Key West

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Charters run daily. Reef, offshore, and flats. Book online or give us a call.

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Fishing Report for Marathon FL