Jellyfishes in Massachusetts in July

Yes, July is a good month to see jellyfishes in Massachusetts. It is the 5th busiest month of the year, with 207 of the 1,950 sightings logged across the year (10.6%), 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.

Lion's Mane Jellies photographed in MassachusettsMoon Jellies photographed in MassachusettsSouthern Moon Jelly photographed in Massachusetts
Photos by iNaturalist observers, used under Creative Commons.

Good month for jellyfishes in Massachusetts

10.6%

of yearly sightings

207

records in July

#5

busiest month of 12

1,950

verified records a year

June 24.2%, July 10.6%, August 15.1%. Busiest month is June at 24.2%.

Best months: June, May, August

1,950 verified observations of jellyfishes in Massachusetts, recorded across 12 months of the year on iNaturalist.

When jellyfishes are recorded in Massachusetts

Peak month

June

471 records (24.2% of the year)

Quietest month

December

3 records

MonthObservationsShare
January40.2%
February60.3%
March522.7%
April22711.6%
Maypeak41921.5%
Junepeak47124.2%
July20710.6%
Augustpeak29515.1%
September1789.1%
October834.3%
November50.3%
December30.2%

Jellyfishes you are most likely to see

SpeciesVerified observations
Atlantic Lion's Mane Jelly610
Common Moon Jelly174
Bay Nettle169
Atlantic Sea Nettle45
Dwarf Lion's Mane Jelly32
Mauve Stinger31
Lion's Mane Jelly10
Southern Moon Jelly8

In Massachusetts, July carries 10.6% of the year's jellyfishes sightings, about 2.3 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 easing off from June (24.2%) into July, and it heads toward August (15.1%) after. The busiest month is June (24.2%), so if timing is flexible, that window is the safer bet.

The jellyfishes most often recorded in Massachusetts are Atlantic Lion's Mane Jelly, Common Moon Jelly and Bay Nettle. Those counts are annual totals rather than a July split, so treat them as which species you are likely to encounter, while the month figures above show how many sightings fall in July itself.

Which jellyfishes you are most likely to see

  • Atlantic Lion's Mane Jelly610 records
  • Common Moon Jelly174 records
  • Bay Nettle169 records
  • Atlantic Sea Nettle45 records
  • Dwarf Lion's Mane Jelly32 records
  • Mauve Stinger31 records
Plan your tripAppalachian National Scenic Trail

Plan your jellyfish trip in Massachusetts

Start with live tours near Appalachian National Scenic Trail, then compare a nearby stay and a broader wildlife backup before you lock in the trip.

Frequently asked questions

Can you see jellyfishes in Massachusetts in July?+

Yes. July accounts for 207 of the 1,950 verified jellyfishes sightings logged in Massachusetts across the year, which is 10.6% of the annual total.

Is July a good time to see jellyfishes in Massachusetts?+

July is the 5th busiest month. It is workable, though June and May is the stronger window for a reliable sighting.

What month is best for jellyfishes in Massachusetts?+

June is the single busiest month, with the broader peak running through June, May and August, based on 1,950 verified observations.

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

The most-recorded species in Massachusetts are Atlantic Lion's Mane Jelly, Common Moon Jelly and Bay Nettle, based on all-time iNaturalist counts.