Jellyfishes in Texas in September

Yes, September is a good month to see jellyfishes in Texas. It is the 5th busiest month of the year, with 410 of the 4,161 sightings logged across the year (9.9%), 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 July 2, 2026.

Good month for jellyfishes in Texas

9.9%

of yearly sightings

410

records in September

#5

busiest month of 12

4,161

verified records a year

August 4.7%, September 9.9%, October 13.2%. Busiest month is October at 13.2%.

Best months: October, November, June

4,161 verified observations of jellyfishes in Texas, recorded across 12 months of the year on iNaturalist.

When jellyfishes are recorded in Texas

Peak month

October

550 records (13.2% of the year)

Quietest month

February

163 records

MonthObservationsShare
January2896.9%
February1633.9%
March2315.6%
April2796.7%
May2917%
Junepeak46211.1%
July3197.7%
August1964.7%
September4109.9%
Octoberpeak55013.2%
Novemberpeak52312.6%
December44810.8%

Jellyfishes you are most likely to see

SpeciesVerified observations
Cannonball Jelly1,267
Bay Nettle821
Southern Moon Jelly747
Atlantic Sea Nettle113
Mushroom Jelly48
Australian Spotted Jelly31
Pink Meanie20
Common Moon Jelly18

In Texas, September carries 9.9% of the year's jellyfishes sightings, about 1.6 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 (4.7%) into September, and it heads toward October (13.2%) after. The busiest month is October (13.2%), so if timing is flexible, that window is the safer bet.

The jellyfishes most often recorded in Texas are Cannonball Jelly, Bay Nettle and Southern Moon 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 Jelly1,267 records
  • Bay Nettle821 records
  • Southern Moon Jelly747 records
  • Atlantic Sea Nettle113 records
  • Mushroom Jelly48 records
  • Australian Spotted Jelly31 records
Plan your tripAmistad National Recreation Area

Plan your jellyfish trip in Texas

Start with live tours near Amistad National Recreation Area, then compare a nearby stay and a broader wildlife backup before you lock in the trip.

Frequently asked questions

Can you see jellyfishes in Texas in September?+

Yes. September accounts for 410 of the 4,161 verified jellyfishes sightings logged in Texas across the year, which is 9.9% of the annual total.

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

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

What month is best for jellyfishes in Texas?+

October is the single busiest month, with the broader peak running through October, November and June, based on 4,161 verified observations.

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

The most-recorded species in Texas are Cannonball Jelly, Bay Nettle and Southern Moon Jelly, based on all-time iNaturalist counts.