Monarch Butterflies in New York in September

Yes, September is one of the best months to see monarch butterflies in New York. It is the 2nd busiest month of the year, with 4,479 of the 17,575 sightings logged across the year (25.5%), based on verified iNaturalist records.

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By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.

Monarch photographed in New YorkMonarch photographed in New YorkMonarch photographed in New York
Photos by iNaturalist observers, used under Creative Commons.

Peak month for monarch butterflies in New York

25.5%

of yearly sightings

4,479

records in September

#2

busiest month of 12

17,575

verified records a year

August 35.7%, September 25.5%, October 9.9%. Busiest month is August at 35.7%.

Best months: August, September, JulyPeak season right now

17,575 verified observations of monarch butterflies in New York, recorded across 11 months of the year on iNaturalist.

When monarch butterflies are recorded in New York

Peak month

August

6,275 records (35.7% of the year)

Quietest month

March

No verified records

MonthObservationsShare
January20%
February10%
March00%
April240.1%
May1841%
June9125.2%
Julypeak3,83921.8%
Augustpeak6,27535.7%
Septemberpeak4,47925.5%
October1,7439.9%
November1090.6%
December70%

Monarch Butterflies you are most likely to see

SpeciesVerified observations
Monarch17,575

In New York, September carries 25.5% of the year's monarch butterflies sightings, about 17.2 points above an even month-to-month split. That makes it the 2nd busiest of the twelve months, out of 11 months with recorded activity.

Activity is easing off from August (35.7%) into September, and it heads toward October (9.9%) after. This is right inside the peak window, so September is one of the surest months to plan a trip around.

The monarch butterflies most often recorded in New York are Monarch. 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 monarch butterflies you are most likely to see

  • Monarch17,575 records
Plan your tripAppalachian National Scenic Trail

Plan your monarch butterfly trip in New York

Start with live tours near Appalachian National Scenic Trail, then compare a nearby stay and a broader wildlife backup before you lock in the trip.

Frequently asked questions

Can you see monarch butterflies in New York in September?+

Yes. September accounts for 4,479 of the 17,575 verified monarch butterflies sightings logged in New York across the year, which is 25.5% of the annual total.

Is September a good time to see monarch butterflies in New York?+

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 monarch butterflies in New York?+

August is the single busiest month, with the broader peak running through August, September and July, based on 17,575 verified observations.

Which monarch butterflies are you most likely to see in New York?+

The most-recorded species in New York are Monarch, based on all-time iNaturalist counts.