Best Time to See Monarch Butterflies in New Jersey
August, September and July is the best time to see monarch butterflies in New Jersey. Based on 7,701 verified iNaturalist observations, here is exactly when monarch butterflies are most active across the year in New Jersey.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.
7,701 verified observations of monarch butterflies in New Jersey, recorded across 12 months of the year on iNaturalist.
When monarch butterflies are recorded in New Jersey
Peak month
August
2,293 records (29.8% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 2 | 0% |
| February | 1 | 0% |
| March | 5 | 0.1% |
| April | 21 | 0.3% |
| May | 114 | 1.5% |
| June | 464 | 6% |
| Julypeak | 1,668 | 21.7% |
| Augustpeak | 2,293 | 29.8% |
| Septemberpeak | 1,956 | 25.4% |
| October | 1,107 | 14.4% |
| November | 69 | 0.9% |
| December | 1 | 0% |
Monarch Butterflies you are most likely to see
| Species | Verified observations |
|---|---|
| Monarch | 7,701 |
Weather to expect, source Open-Meteo
Typical weather in New Jersey
Recent typical conditions by month, so you can plan a trip around both when monarch butterflies are active and what the weather is doing. The best months to look for monarch butterflies sit around 61 to 88 degrees Fahrenheit, so pack for that.
| Month | Avg high | Avg low | Rain |
|---|---|---|---|
| Jan | 43°F | 28°F | 3.4" |
| Feb | 45°F | 29°F | 3.5" |
| Mar | 54°F | 35°F | 4.3" |
| Apr | 63°F | 44°F | 4.6" |
| May | 72°F | 53°F | 4.1" |
| Jun | 82°F | 63°F | 4.1" |
| Julbest time | 88°F | 70°F | 5.2" |
| Augbest time | 85°F | 69°F | 4.3" |
| Sepbest time | 78°F | 61°F | 4.4" |
| Oct | 68°F | 52°F | 4.7" |
| Nov | 55°F | 39°F | 3" |
| Dec | 46°F | 32°F | 4.6" |
Typical recent conditions (5-year means) from the Open-Meteo archive, averaged for New Jersey. Weather varies year to year, so treat these as a guide.
More on monarch butterflies in New Jersey:
Sightings of monarch butterflies in New Jersey peak in August, when 2,293 of the year's 7,701 verified observations are logged — about 29.8% of the annual total. Activity stays high through August, September and July.
The quietest stretch is February and December, when monarch butterflies are hardest to find — February sees just 1 records. If a reliable sighting matters, plan around the peak window rather than the off-season.
The monarch butterflies you are most likely to encounter in New Jersey are Monarch — 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 monarch butterflies in New Jersey
- Appalachian National Scenic Trail — National Scenic Trail
- Delaware Water Gap National Recreation Area — National Recreation Area
- Great Egg Harbor River
- Morristown National Historical Park — National Historical Park
- Ellis Island Part of Statue of Liberty National Monument — Part of Statue of Liberty National Monument
- Gateway National Recreation Area — National Recreation Area
Frequently asked questions
What is the best month to see monarch butterflies in New Jersey?+
August is the single best month, and the broader peak window runs through August, September and July, based on 7,701 verified iNaturalist observations.
When are monarch butterflies hardest to see in New Jersey?+
February is the quietest month for monarch butterflies in New Jersey, with only 1 verified records.
Are monarch butterflies active year-round in New Jersey?+
Monarch butterflies are recorded in 12 of 12 months in New Jersey, so they can be seen year-round, with a clear peak in August.
More places to see monarch butterflies
More wildlife in New Jersey