Jellyfishes in Florida in September

Yes, September is a good month to see jellyfishes in Florida. It is the 5th busiest month of the year, with 637 of the 7,533 sightings logged across the year (8.5%), based on verified iNaturalist records.

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By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.

Good month for jellyfishes in Florida

8.5%

of yearly sightings

637

records in September

#5

busiest month of 12

7,533

verified records a year

August 7.2%, September 8.5%, October 10.1%. Busiest month is March at 15.4%.

Best months: March, February, October

7,533 verified observations of jellyfishes in Florida, recorded across 12 months of the year on iNaturalist.

When jellyfishes are recorded in Florida

Peak month

March

1,159 records (15.4% of the year)

Quietest month

June

335 records

MonthObservationsShare
January6048%
Februarypeak83411.1%
Marchpeak1,15915.4%
April4866.5%
May5607.4%
June3354.4%
July3674.9%
August5407.2%
September6378.5%
Octoberpeak76310.1%
November6028%
December6468.6%

Jellyfishes you are most likely to see

SpeciesVerified observations
Cannonball Jelly1,745
Southern Moon Jelly1,197
Mangrove Upsidedown Jelly1,101
Mushroom Jelly548
Bay Nettle368
Cassiopea xamachana303
Dwarf Lion's Mane Jelly273
Pink Meanie174

In Florida, September carries 8.5% of the year's jellyfishes sightings, about 0.2 points above an even month-to-month split. That makes it the 5th busiest of the twelve months, out of 12 months with recorded activity.

Activity is rising from August (7.2%) into September, and it heads toward October (10.1%) after. The busiest month is March (15.4%), so if timing is flexible, that window is the safer bet.

The jellyfishes most often recorded in Florida are Cannonball Jelly, Southern Moon Jelly and Mangrove Upsidedown Jelly. Those counts are annual totals rather than a September split, so treat them as which species you are likely to encounter, while the month figures above show how many sightings fall in September itself.

Which jellyfishes you are most likely to see

  • Cannonball Jelly1,745 records
  • Southern Moon Jelly1,197 records
  • Mangrove Upsidedown Jelly1,101 records
  • Mushroom Jelly548 records
  • Bay Nettle368 records
  • Cassiopea xamachana303 records
Plan your tripBig Cypress National Preserve

Plan your jellyfish trip in Florida

Start with live tours near Big Cypress National Preserve, then compare a nearby stay and a broader wildlife backup before you lock in the trip.

Frequently asked questions

Can you see jellyfishes in Florida in September?+

Yes. September accounts for 637 of the 7,533 verified jellyfishes sightings logged in Florida across the year, which is 8.5% of the annual total.

Is September a good time to see jellyfishes in Florida?+

September is the 5th busiest month. It is workable, though March and February is the stronger window for a reliable sighting.

What month is best for jellyfishes in Florida?+

March is the single busiest month, with the broader peak running through March, February and October, based on 7,533 verified observations.

Which jellyfishes are you most likely to see in Florida?+

The most-recorded species in Florida are Cannonball Jelly, Southern Moon Jelly and Mangrove Upsidedown Jelly, based on all-time iNaturalist counts.