Jellyfishes in Oregon in September
Yes, September is one of the best months to see jellyfishes in Oregon. It is the 2nd busiest month of the year, with 798 of the 3,455 sightings logged across the year (23.1%), based on verified iNaturalist records.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated July 2, 2026.
Peak month for jellyfishes in Oregon
23.1%
of yearly sightings
798
records in September
#2
busiest month of 12
3,455
verified records a year
August 27.1%, September 23.1%, October 10.8%. Busiest month is August at 27.1%.
3,455 verified observations of jellyfishes in Oregon, recorded across 12 months of the year on iNaturalist.
When jellyfishes are recorded in Oregon
Peak month
August
935 records (27.1% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 111 | 3.2% |
| February | 98 | 2.8% |
| March | 54 | 1.6% |
| April | 25 | 0.7% |
| May | 66 | 1.9% |
| June | 228 | 6.6% |
| Julypeak | 478 | 13.8% |
| Augustpeak | 935 | 27.1% |
| Septemberpeak | 798 | 23.1% |
| October | 373 | 10.8% |
| November | 173 | 5% |
| December | 116 | 3.4% |
Jellyfishes you are most likely to see
| Species | Verified observations |
|---|---|
| Pacific Sea Nettle | 1,217 |
| Greater Moon Jelly | 856 |
| Pacific Lion's Mane Jelly | 786 |
| Egg-yolk Jelly | 116 |
| Purple-striped Sea Nettle | 9 |
| Barrel Jellies | 1 |
In Oregon, September carries 23.1% of the year's jellyfishes sightings, about 14.8 points above an even month-to-month split. That makes it the 2nd busiest of the twelve months, out of 12 months with recorded activity.
Activity is easing off from August (27.1%) into September, and it heads toward October (10.8%) after. This is right inside the peak window, so September is one of the surest months to plan a trip around.
The jellyfishes most often recorded in Oregon are Pacific Sea Nettle, Greater Moon Jelly and Pacific Lion's Mane 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
- Pacific Sea Nettle1,217 records
- Greater Moon Jelly856 records
- Pacific Lion's Mane Jelly786 records
- Egg-yolk Jelly116 records
- Purple-striped Sea Nettle9 records
- Barrel Jellies1 records
Plan your jellyfish trip in Oregon
Start with live tours near Crater Lake National Park, then compare a nearby stay and a broader wildlife backup before you lock in the trip.
GetYourGuide
Live tours nearbySee live tours near Crater Lake National Park
Use the live GetYourGuide widget to compare local departures and activity styles close to the main jellyfish viewing area.
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Stay nearbyStay near Crater Lake National Park
Compare hotels, cabins and lodges close to the best jellyfish viewing area in Oregon.
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Broader backupBook a jellyfish tour in Oregon
Compare guided wildlife tours, boat trips and nature experiences if you want a second travel network beyond the live widget.
Frequently asked questions
Can you see jellyfishes in Oregon in September?+
Yes. September accounts for 798 of the 3,455 verified jellyfishes sightings logged in Oregon across the year, which is 23.1% of the annual total.
Is September a good time to see jellyfishes in Oregon?+
September is one of the best months. It ranks 2nd of the year and sits inside the peak window of August, September and July.
What month is best for jellyfishes in Oregon?+
August is the single busiest month, with the broader peak running through August, September and July, based on 3,455 verified observations.
Which jellyfishes are you most likely to see in Oregon?+
The most-recorded species in Oregon are Pacific Sea Nettle, Greater Moon Jelly and Pacific Lion's Mane Jelly, based on all-time iNaturalist counts.
See jellyfishes in Oregon in other months
More places to see jellyfishes
More wildlife in Oregon