Best Time to See Jellyfishes in Washington
July, June and August is the best time to see jellyfishes in Washington. Based on 6,847 verified iNaturalist observations, here is exactly when jellyfishes are most active across the year in Washington.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.
Pacific Lion's Mane Jelly · Public domain CC0
Pacific Lion's Mane Jelly · jjfeiler CC BY
Egg-yolk Jelly · Public domain CC0
6,847 verified observations of jellyfishes in Washington, recorded across 12 months of the year on iNaturalist.
When jellyfishes are recorded in Washington
Peak month
July
1,633 records (23.8% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 94 | 1.4% |
| February | 44 | 0.6% |
| March | 58 | 0.8% |
| April | 108 | 1.6% |
| May | 408 | 6% |
| Junepeak | 1,485 | 21.7% |
| Julypeak | 1,633 | 23.8% |
| Augustpeak | 1,166 | 17% |
| September | 791 | 11.6% |
| October | 596 | 8.7% |
| November | 326 | 4.8% |
| December | 138 | 2% |
Jellyfishes you are most likely to see
| Species | Verified observations |
|---|---|
| Egg-yolk Jelly | 2,875 |
| Pacific Lion's Mane Jelly | 1,923 |
| Greater Moon Jelly | 938 |
| Pacific Sea Nettle | 372 |
| Asian moon jellyfish | 4 |
| Common Moon Jelly | 2 |
| Crown Jellies | 1 |
Weather to expect, source Open-Meteo
Typical weather in Washington
Recent typical conditions by month, so you can plan a trip around both when jellyfishes are active and what the weather is doing. The best months to look for jellyfishes sit around 51 to 86 degrees Fahrenheit, so pack for that.
| Month | Avg high | Avg low | Rain |
|---|---|---|---|
| Jan | 35°F | 24°F | 4.5" |
| Feb | 36°F | 22°F | 2.8" |
| Mar | 46°F | 28°F | 1.2" |
| Apr | 56°F | 33°F | 1.3" |
| May | 67°F | 44°F | 1.2" |
| Junbest time | 76°F | 51°F | 0.9" |
| Julbest time | 86°F | 57°F | 0.2" |
| Augbest time | 86°F | 58°F | 0.3" |
| Sep | 74°F | 50°F | 1.1" |
| Oct | 59°F | 39°F | 1.7" |
| Nov | 42°F | 29°F | 3.6" |
| Dec | 33°F | 23°F | 3.6" |
Typical recent conditions (5-year means) from the Open-Meteo archive, averaged for Washington. Weather varies year to year, so treat these as a guide.
Sightings of jellyfishes in Washington peak in July, when 1,633 of the year's 6,847 verified observations are logged — about 23.8% of the annual total. Activity stays high through July, June and August.
The quietest stretch is February and March, when jellyfishes are hardest to find — February sees just 44 records. If a reliable sighting matters, plan around the peak window rather than the off-season.
The jellyfishes you are most likely to encounter in Washington are Egg-yolk Jelly, Pacific Lion's Mane Jelly and Greater Moon Jelly — the most-recorded species in the state. Each keeps its own seasonal rhythm, but the month-by-month pattern above reflects every reported sighting together.
Where to go
Best places to see jellyfishes in Washington
- Ebey's Landing National Historical Reserve — National Historical Reserve
- Fort Vancouver National Historic Site — National Historic Site
- Lewis & Clark National Historic Trail — National Historic Trail
- Lewis and Clark National Historical Park — National Historical Park
- Mount Rainier National Park — National Park
- Nez Perce National Historical Park — National Historical Park
Frequently asked questions
What is the best month to see jellyfishes in Washington?+
July is the single best month, and the broader peak window runs through July, June and August, based on 6,847 verified iNaturalist observations.
When are jellyfishes hardest to see in Washington?+
February is the quietest month for jellyfishes in Washington, with only 44 verified records.
Are jellyfishes active year-round in Washington?+
Jellyfishes are recorded in 12 of 12 months in Washington, so they can be seen year-round, with a clear peak in July.
More places to see jellyfishes
More wildlife in Washington