Best Time to See Seals in Massachusetts
August, July and June is the best time to see seals in Massachusetts. Based on 3,245 verified iNaturalist observations, here is exactly when seals are most active across the year in Massachusetts.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.
Atlantic Grey Seal · Kevin Lynch CC BY
Atlantic Grey Seal · Kevin Lynch CC BY
Atlantic Grey Seal · gabbieb CC BY
3,245 verified observations of seals in Massachusetts, recorded across 12 months of the year on iNaturalist.
When seals are recorded in Massachusetts
Peak month
August
494 records (15.2% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 195 | 6% |
| February | 164 | 5.1% |
| March | 204 | 6.3% |
| April | 186 | 5.7% |
| May | 207 | 6.4% |
| Junepeak | 396 | 12.2% |
| Julypeak | 405 | 12.5% |
| Augustpeak | 494 | 15.2% |
| September | 265 | 8.2% |
| October | 235 | 7.2% |
| November | 273 | 8.4% |
| December | 221 | 6.8% |
Seals you are most likely to see
| Species | Verified observations |
|---|---|
| Grey Seal | 2,068 |
| Harbor Seal | 943 |
| Harp Seal | 57 |
| Hooded Seal | 1 |
Weather to expect, source Open-Meteo
Typical weather in Massachusetts
Recent typical conditions by month, so you can plan a trip around both when seals are active and what the weather is doing. The best months to look for seals sit around 58 to 83 degrees Fahrenheit, so pack for that.
| Month | Avg high | Avg low | Rain |
|---|---|---|---|
| Jan | 37°F | 22°F | 3.8" |
| Feb | 39°F | 22°F | 3.4" |
| Mar | 48°F | 28°F | 3.6" |
| Apr | 57°F | 38°F | 4.6" |
| May | 68°F | 47°F | 3.4" |
| Junbest time | 78°F | 58°F | 3.6" |
| Julbest time | 83°F | 65°F | 5.4" |
| Augbest time | 82°F | 64°F | 3.5" |
| Sep | 73°F | 56°F | 5.3" |
| Oct | 62°F | 47°F | 5.3" |
| Nov | 50°F | 34°F | 3.1" |
| Dec | 42°F | 27°F | 5.9" |
Typical recent conditions (5-year means) from the Open-Meteo archive, averaged for Massachusetts. Weather varies year to year, so treat these as a guide.
More on seals in Massachusetts:
Sightings of seals in Massachusetts peak in August, when 494 of the year's 3,245 verified observations are logged — about 15.2% of the annual total. Activity stays high through August, July and June.
The quietest stretch is February, April and January, when seals are hardest to find — February sees just 164 records. If a reliable sighting matters, plan around the peak window rather than the off-season.
The seals you are most likely to encounter in Massachusetts are Grey Seal, Harbor Seal and Harp Seal — 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 seals in Massachusetts
- Appalachian National Scenic Trail — National Scenic Trail
- Blackstone River Valley National Historical Park — National Historical Park
- Boston Harbor Islands National Recreation Area — National Recreation Area
- Cape Cod National Seashore — National Seashore
- Adams National Historical Park — National Historical Park
- Boston African American National Historic Site — National Historic Site
Frequently asked questions
What is the best month to see seals in Massachusetts?+
August is the single best month, and the broader peak window runs through August, July and June, based on 3,245 verified iNaturalist observations.
When are seals hardest to see in Massachusetts?+
February is the quietest month for seals in Massachusetts, with only 164 verified records.
Are seals active year-round in Massachusetts?+
Seals are recorded in 12 of 12 months in Massachusetts, so they can be seen year-round, with a clear peak in August.
More places to see seals
More wildlife in Massachusetts