Monarch Butterflies in Delaware in September
Yes, September is one of the best months to see monarch butterflies in Delaware. It is the 2nd busiest month of the year, with 404 of the 1,497 sightings logged across the year (27%), based on verified iNaturalist records.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.
Peak month for monarch butterflies in Delaware
27%
of yearly sightings
404
records in September
#2
busiest month of 12
1,497
verified records a year
August 30.7%, September 27%, October 9.5%. Busiest month is August at 30.7%.
1,497 verified observations of monarch butterflies in Delaware, recorded across 12 months of the year on iNaturalist.
When monarch butterflies are recorded in Delaware
Peak month
August
460 records (30.7% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 1 | 0.1% |
| February | 1 | 0.1% |
| March | 2 | 0.1% |
| April | 6 | 0.4% |
| May | 66 | 4.4% |
| June | 140 | 9.4% |
| Julypeak | 262 | 17.5% |
| Augustpeak | 460 | 30.7% |
| Septemberpeak | 404 | 27% |
| October | 142 | 9.5% |
| November | 11 | 0.7% |
| December | 2 | 0.1% |
Monarch Butterflies you are most likely to see
| Species | Verified observations |
|---|---|
| Monarch | 1,497 |
In Delaware, September carries 27% of the year's monarch butterflies sightings, about 18.7 points above an even month-to-month split. That makes it the 2nd busiest of the twelve months, out of 12 months with recorded activity.
Activity is easing off from August (30.7%) into September, and it heads toward October (9.5%) 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 Delaware 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
- Monarch1,497 records
Plan your monarch butterfly trip in Delaware
Start with live tours near Captain John Smith Chesapeake National Historic Trail, then compare a nearby stay and a broader wildlife backup before you lock in the trip.
GetYourGuide
Live tours nearbySee live tours near Captain John Smith Chesapeake National Historic Trail
Use the live GetYourGuide widget to compare local departures and activity styles close to the main monarch butterfly viewing area.
Booking.com
Stay nearbyStay near Captain John Smith Chesapeake National Historic Trail
Compare hotels, cabins and lodges close to the best monarch butterfly viewing area in Delaware.
Viator
Broader backupBook a monarch butterfly tour in Delaware
Compare guided wildlife tours, boat trips and nature experiences if you want a second travel network beyond the live widget.
Frequently asked questions
Can you see monarch butterflies in Delaware in September?+
Yes. September accounts for 404 of the 1,497 verified monarch butterflies sightings logged in Delaware across the year, which is 27% of the annual total.
Is September a good time to see monarch butterflies in Delaware?+
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 Delaware?+
August is the single busiest month, with the broader peak running through August, September and July, based on 1,497 verified observations.
Which monarch butterflies are you most likely to see in Delaware?+
The most-recorded species in Delaware are Monarch, based on all-time iNaturalist counts.
See monarch butterflies in Delaware in other months
More wildlife in Delaware