Sunday, September 20, 2026

☀️ Today's Gulf Coast Snapshot

Here's what families really need to know this Sunday:

🌊 Red tide: The newest statewide report found Karenia brevis at background concentration in one Sarasota County sample. That's the lowest concentration category, with no effects anticipated at that level.

🟤 Sanibel & Captiva: The rare rust-tide bloom remains our most important local environmental watch. Current bacterial testing at monitored Sanibel beaches remains good.

🏖️ Clearwater → Anna Maria → Siesta Key: Low rip-current risk, surf 1 foot or less and calm morning conditions.

🏖️ Sanibel & Fort Myers Beach: Low rip-current risk and surf of 1 foot or less, but numerous showers and scattered thunderstorms are possible.

🏖️ Naples & Marco Island: Low rip-current risk and small surf, with showers and thunderstorms possible later.

⛈️ Weather: Morning is your friend today. Thunderstorms become a bigger issue this afternoon across central and Southwest Florida.

🌀 Tropics: Tropical Depression Six has formed far out in the eastern Atlantic. It is not currently a Florida threat.

Mom Takeaway: Pack the beach bag and go earlier. Most of the Gulf Coast looks perfectly usable this morning, but don't lock the family into an all-day outdoor schedule.

🌊 Red Tide: One Background Sarasota County Detection

Friday's newest statewide report gives us a little more detail than we had yesterday.

One sample from Sarasota County contained background-level Karenia brevis.

Importantly, background means 1,000 cells per liter or less.

At that concentration:

No effects are anticipated.

No K. brevis was observed in Northwest Florida or along Florida's East Coast during the reporting week.

There were also:

No suspected red-tide fish kills.

No reported respiratory irritation associated with red tide.

So this is something RTG should monitor—but not something families should interpret as a significant red-tide event.

The next statewide report is expected Friday, September 25, with daily sampling continuing between reports.

Mom Takeaway: If you're considering Clearwater, Anna Maria Island, Siesta Key, Naples or Marco Island, there is currently no significant red-tide problem telling us to steer your family somewhere else.

🟤 Sanibel & Captiva: Rust Tide Remains Our Local Watch

We're keeping Sanibel in this section because the unusual bloom remains relevant.

The organism involved is:

Margalefidinium polykrikoides

often called rust tide.

Recent monitoring documented varying concentrations around:

Tarpon Bay

Sanibel

Captiva

North Captiva

Cayo Costa

At high concentrations, the algae can give the water a distinctive rust-colored appearance and can potentially harm fish and shellfish.

But three distinctions remain extremely important:

1. This is NOT Florida red tide.

It's a different organism from Karenia brevis.

2. It's not known to harm humans or produce the airborne brevetoxins associated with Florida red tide.

3. No known fish kills or wildlife impacts have been reported from this bloom.

And there's more reassuring news for families.

Current bacterial water-quality monitoring remains rated Good at:

🟢 Bowman's Beach
🟢 Lighthouse Beach
🟢 Blind Pass/Turner Beach
🟢 Sanibel Causeway
🟢 Bonita Beach Park
🟢 Bowditch Park

So our Sunday assessment remains:

Bacterial water quality: 🟢 Good

Florida red tide: 🟡 One background Sarasota County detection

Sanibel rust tide: 🟡 Present locally and still being monitored

Mom Takeaway: Don't cancel Sanibel. Check your actual beach.

If the water looks normal, don't assume the entire island has poor conditions.

If it's obviously rust-colored, reddish-brown, unusually dark or algae-heavy:

Stay out of that water and choose another beach or activity.

🏖️ Where Conditions Look Best Today

Clearwater & St. Pete — 🟢 Looking Very Good This Morning

Sunday starts nicely.

Expect:

🟢 Low rip-current risk

🌊 Surf 1 foot or less

🌡️ Upper-80s Gulf water

☀️ Mostly sunny conditions

⛈️ Scattered showers and thunderstorms later

This is a good example of a day where the thunderstorm icon shouldn't scare families away from the beach.

Go earlier.

Anna Maria Island — 🟢 Looking Very Good This Morning

Another strong Sunday choice.

Swimming conditions are favorable, with low rip-current risk and small surf.

Afternoon thunderstorms become the bigger consideration later.

Longboat Key, Lido Key & Siesta Key — 🟢 Looking Very Good

This may be our strongest region this morning.

Expect:

🟢 Low rip-current risk

🌊 Surf 1 foot or less

☀️ Mostly sunny start

💨 Light winds

⛈️ Scattered afternoon thunderstorms

Use the morning.

There's no reason to waste a beautiful early beach window worrying about storms that may develop later.

Sanibel & Captiva — 🟡 Algae Awareness

Actual swimming conditions are calm:

🟢 Low rip-current risk

🌊 Surf 1 foot or less

🌡️ Upper-80s Gulf water

But we're keeping Sanibel and Captiva yellow because of the rust-tide bloom.

There's also a greater chance of showers and thunderstorms here today.

Look at the water before getting in.

Naples & Marco Island — 🟢 Looking Good

Sunday's swimming setup remains favorable:

🟢 Low rip-current risk

🌊 Surf 1 foot or less

☀️ Mostly sunny periods

⛈️ Chance of showers and thunderstorms

The best strategy again is earlier rather than later.

🏖️ 30A & Panama City Beach — Check Today's Flags

The Panhandle has improved dramatically from the high rip-current conditions we saw earlier in the week.

Surf remains relatively small, and the stronger easterly winds responsible for those rougher midweek conditions have eased.

Still, always check the actual beach flags when you arrive, because rip-current conditions can vary locally and change during the day.

Farther west around Pensacola, Navarre and Destin, today's forecast shows low rip-current risk and surf around 1 foot.

Mom Takeaway: The Panhandle looks much more inviting than it did Wednesday and Thursday. Enjoy it—but the flag flying at your beach always wins over a regional forecast.

⛈️ Will Rain Ruin Sunday?

Probably not.

But today is one of those days where timing can turn an okay beach day into a really good one.

Around Clearwater, Anna Maria and Sarasota:

The morning looks great.

Then scattered afternoon showers and thunderstorms become more likely.

Some storms today could also produce:

⚡ Frequent lightning

💨 Gusty winds

🌧️ Heavy downpours

And slow-moving storms could cause localized flooding in spots.

Farther south around Sanibel, showers and thunderstorms are somewhat more numerous.

So don't spend the morning staring at radar waiting for perfect conditions.

Go while it's good.

Our Sunday family strategy:

Morning beach → lunch/heat break → check radar → decide what to do next.

And always:

If you hear thunder, everyone gets out of the water.

🌀 Tropical Weather: Tropical Depression Six Has Formed

We have a tropical system to talk about today—but this is also a good example of why location matters more than the headline.

Yesterday's AL99 disturbance organized into:

Tropical Depression Six

It's located in the eastern Atlantic, roughly 2,700 miles from Florida, southwest of the Azores.

The system has been moving slowly north-northeastward.

Now the part Florida families actually care about:

This is NOT currently a Florida Gulf Coast threat.

It's nowhere near the Gulf.

It's nowhere near Florida.

And nothing about its current position should cause families to change a Florida Gulf Coast vacation.

Mom Takeaway: If you see a headline saying “Tropical Depression Forms in Atlantic,” don't panic.

Where the storm is—and where it's going—matters.

For now:

Keep the Florida vacation plans.

🌿 Seaweed & Water Quality

The Sanibel situation continues to reinforce something important:

Not every algae bloom is red tide.

Right now, families may hear about:

Rust tide near Sanibel

One background K. brevis detection in Sarasota County

Sargassum at individual beaches

Bacterial water-quality testing

Those are different things.

And they require different vacation decisions.

The encouraging part is that all 12 currently listed monitored Lee County beaches are rated Good for bacterial water quality, including the major Sanibel-area monitoring locations.

So don't turn the phrase:

“Algae bloom in Southwest Florida”

into:

“We shouldn't book Southwest Florida.”

That's exactly the kind of unnecessary leap RTG should help families avoid.

Mom Takeaway: Check the actual beach and understand the actual issue.

🌴 RTG Vacation Watch — Florida Keys & Key West

Status: 🟡 Good Vacation Conditions / Wet Pattern Continues

Key West remains a good vacation destination today—but definitely keep the schedule flexible.

Sunday's forecast calls for approximately:

🌡️ High around 89°F

⛈️ 70% chance of showers and thunderstorms

The Middle Keys are also around 70%, while Key Largo is around 60%.

And this isn't just a one-day pattern.

Elevated thunderstorm chances continue into the coming week.

That matters most if you're paying for:

Snorkeling

Fishing

Boat tours

Diving

Sunset cruises

It doesn't mean cancel the trip.

It means:

Check conditions before spending six hours on the water.

Mom Takeaway: Keep Key West. Keep the schedule flexible.

🏆 Best Beaches Right Now

🥇 Siesta Key — Low rip-current risk, tiny surf and a beautiful morning window make Siesta our strongest overall family choice today.

🥈 Anna Maria Island — Another excellent Sunday choice. Get the beach time earlier before thunderstorms become more likely.

🥉 Clearwater Beach — Favorable swimming conditions and plenty of usable morning beach weather keep Clearwater near the top.

Beach We're Watching Most Closely: Sanibel Island 🟡

Sanibel remains our watch beach because of the rare rust-tide bloom.

Importantly, though:

Bacterial water quality remains good.

Swimming conditions are calm.

No known rust-tide fish kills or wildlife impacts have been reported.

So this remains a monitor-and-check-your-beach situation, not a cancel-Sanibel situation.

❤️ What This Means for Your Family

If you're waking up this Sunday asking:

“Should we go to the beach?”

Yes—go earlier.

Clearwater, St. Pete, Anna Maria or Siesta Key?

Very good morning choices.

Naples or Marco Island?

Keep the plans and watch the afternoon weather.

30A, Destin or the Panhandle?

Conditions have improved considerably compared with earlier this week. Check your local flags and enjoy the beach responsibly.

Worried about red tide?

There's one background-level Sarasota County detection—not evidence of a significant Florida red-tide bloom.

Worried because a tropical depression formed?

Don't be for your Florida vacation.

It's roughly 2,700 miles away and is not currently a Florida threat.

And if you're staying on Sanibel or Captiva:

Don't cancel the vacation. Check your actual beach.

If the water looks normal, enjoy it while continuing to monitor local conditions.

If it's obviously reddish-brown, rust-colored or algae-heavy:

Choose another beach or activity.

That's really Sunday's story.

Most of the Florida Gulf Coast looks good this morning. Use the early beach window, keep radar handy for the afternoon, and continue watching Sanibel's unusual rust-tide bloom beach by beach rather than treating it as a Southwest Florida-wide problem.

Looking For Beach-Specific Updates?

Thank you for reading today's free Florida Gulf Coast Beach Vacation Outlook™.

For destination-specific guidance, the RTG Travel Confidence Pass™ monitors conditions across 5 Florida Gulf Coast regions and 20+ premier beach destinations, plus Florida Keys and Key West updates when conditions warrant.

The best time to use RTG is before choosing your destination, so you can compare beaches and know what conditions look like before spending thousands on your vacation.

RTG helps families answer three simple questions:

✔️ WHERE should we go?

✔️ WHEN should we go?

✔️ WHICH beach is right for our family?

Know Your Beach Before You Go™ 🌊🏖️