Best Time to See Jellyfishes in New Hampshire
June, July and May is the best time to see jellyfishes in New Hampshire. Based on 56 verified iNaturalist observations, here is exactly when jellyfishes are most active across the year in New Hampshire.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.
Atlantic Lion's Mane Jelly · Eli Talhouk CC BY
Atlantic Lion's Mane Jelly · Eli Talhouk CC BY
Atlantic Lion's Mane Jelly · Eli Talhouk CC BY
56 verified observations of jellyfishes in New Hampshire, recorded across 4 months of the year on iNaturalist.
When jellyfishes are recorded in New Hampshire
Peak month
June
21 records (37.5% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 0 | 0% |
| February | 0 | 0% |
| March | 0 | 0% |
| April | 0 | 0% |
| Maypeak | 12 | 21.4% |
| Junepeak | 21 | 37.5% |
| Julypeak | 15 | 26.8% |
| August | 8 | 14.3% |
| September | 0 | 0% |
| October | 0 | 0% |
| November | 0 | 0% |
| December | 0 | 0% |
Jellyfishes you are most likely to see
| Species | Verified observations |
|---|---|
| Atlantic Lion's Mane Jelly | 18 |
| Common Moon Jelly | 2 |
| Sea Nettles | 1 |
| Lion's Mane Jelly | 1 |
| Purple-striped Jellies | 1 |
Weather to expect, source Open-Meteo
Typical weather in New Hampshire
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 40 to 72 degrees Fahrenheit, so pack for that.
| Month | Avg high | Avg low | Rain |
|---|---|---|---|
| Jan | 24°F | 8°F | 4.1" |
| Feb | 25°F | 8°F | 3.6" |
| Mar | 34°F | 18°F | 3.3" |
| Apr | 45°F | 29°F | 5.2" |
| Maybest time | 58°F | 40°F | 4.1" |
| Junbest time | 67°F | 50°F | 4.8" |
| Julbest time | 72°F | 57°F | 7.1" |
| Aug | 70°F | 56°F | 4.5" |
| Sep | 63°F | 48°F | 4.5" |
| Oct | 53°F | 39°F | 5.6" |
| Nov | 38°F | 24°F | 4.2" |
| Dec | 30°F | 17°F | 6" |
Typical recent conditions (5-year means) from the Open-Meteo archive, averaged for New Hampshire. Weather varies year to year, so treat these as a guide.
Sightings of jellyfishes in New Hampshire peak in June, when 21 of the year's 56 verified observations are logged — about 37.5% of the annual total. Activity stays high through June, July and May.
The quietest stretch is January, February and March, when jellyfishes are hardest to find — no verified records exist for January. If a reliable sighting matters, plan around the peak window rather than the off-season.
The jellyfishes you are most likely to encounter in New Hampshire are Atlantic Lion's Mane Jelly, Common Moon Jelly and Sea Nettles — 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 New Hampshire
- Appalachian National Scenic Trail — National Scenic Trail
- Saint-Gaudens National Historical Park — National Historical Park
Frequently asked questions
What is the best month to see jellyfishes in New Hampshire?+
June is the single best month, and the broader peak window runs through June, July and May, based on 56 verified iNaturalist observations.
When are jellyfishes hardest to see in New Hampshire?+
January is the quietest month for jellyfishes in New Hampshire, with no verified records on iNaturalist.
Are jellyfishes active year-round in New Hampshire?+
Jellyfishes are recorded in 4 of 12 months in New Hampshire, concentrated around June and July.
More places to see jellyfishes
More wildlife in New Hampshire