Monarch Butterflies in Pennsylvania in August

Yes, August is one of the best months to see monarch butterflies in Pennsylvania. It is the 1st busiest month of the year, with 4,600 of the 11,660 sightings logged across the year (39.5%), 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 July 2, 2026.

Monarch photographed in PennsylvaniaMonarch photographed in PennsylvaniaMonarch photographed in Pennsylvania
Photos by iNaturalist observers, used under Creative Commons.

Peak month for monarch butterflies in Pennsylvania

39.5%

of yearly sightings

4,600

records in August

#1

busiest month of 12

11,660

verified records a year

July 23.7%, August 39.5%, September 24.2%. Busiest month is August at 39.5%.

Best months: August, September, JulyPeak season right now

11,660 verified observations of monarch butterflies in Pennsylvania, recorded across 11 months of the year on iNaturalist.

When monarch butterflies are recorded in Pennsylvania

Peak month

August

4,600 records (39.5% of the year)

Quietest month

January

No verified records

MonthObservationsShare
January00%
February20%
March40%
April290.2%
May1070.9%
June6095.2%
Julypeak2,76423.7%
Augustpeak4,60039.5%
Septemberpeak2,82124.2%
October6775.8%
November420.4%
December50%

Monarch Butterflies you are most likely to see

SpeciesVerified observations
Monarch11,660

In Pennsylvania, August carries 39.5% of the year's monarch butterflies sightings, about 31.2 points above an even month-to-month split. That makes it the 1st busiest of the twelve months, out of 11 months with recorded activity.

Activity is rising from July (23.7%) into August, and it heads toward September (24.2%) after. This is right inside the peak window, so August is one of the surest months to plan a trip around.

The monarch butterflies most often recorded in Pennsylvania are Monarch. Those counts are annual totals rather than a August split, so treat them as which species you are likely to encounter, while the month figures above show how many sightings fall in August itself.

Which monarch butterflies you are most likely to see

  • Monarch11,660 records
Plan your tripAppalachian National Scenic Trail

Plan your monarch butterfly trip in Pennsylvania

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 Pennsylvania in August?+

Yes. August accounts for 4,600 of the 11,660 verified monarch butterflies sightings logged in Pennsylvania across the year, which is 39.5% of the annual total.

Is August a good time to see monarch butterflies in Pennsylvania?+

August is one of the best months. It ranks 1st of the year and sits inside the peak window of August, September and July.

What month is best for monarch butterflies in Pennsylvania?+

August is the single busiest month, with the broader peak running through August, September and July, based on 11,660 verified observations.

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

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