Monarch Butterflies in Illinois in June

Yes, June is a good month to see monarch butterflies in Illinois. It is the 4th busiest month of the year, with 1,750 of the 15,827 sightings logged across the year (11.1%), 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.

Migratory Monarch photographed in IllinoisMonarch photographed in IllinoisMonarch photographed in Illinois
Photos by iNaturalist observers, used under Creative Commons.

Good month for monarch butterflies in Illinois

11.1%

of yearly sightings

1,750

records in June

#4

busiest month of 12

15,827

verified records a year

May 3.6%, June 11.1%, July 27.3%. Busiest month is August at 30.2%.

Best months: August, July, SeptemberPeak season right now

15,827 verified observations of monarch butterflies in Illinois, recorded across 10 months of the year on iNaturalist.

When monarch butterflies are recorded in Illinois

Peak month

August

4,777 records (30.2% of the year)

Quietest month

January

No verified records

MonthObservationsShare
January00%
February10%
March00%
April470.3%
May5713.6%
June1,75011.1%
Julypeak4,32527.3%
Augustpeak4,77730.2%
Septemberpeak3,58222.6%
October7274.6%
November460.3%
December10%

Monarch Butterflies you are most likely to see

SpeciesVerified observations
Monarch15,827

In Illinois, June carries 11.1% of the year's monarch butterflies sightings, about 2.8 points above an even month-to-month split. That makes it the 4th busiest of the twelve months, out of 10 months with recorded activity.

Activity is rising from May (3.6%) into June, and it heads toward July (27.3%) after. The busiest month is August (30.2%), so if timing is flexible, that window is the safer bet.

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

Which monarch butterflies you are most likely to see

  • Monarch15,827 records
Plan your tripLewis & Clark National Historic Trail

Plan your monarch butterfly trip in Illinois

Start with live tours near Lewis & Clark National Historic 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 Illinois in June?+

Yes. June accounts for 1,750 of the 15,827 verified monarch butterflies sightings logged in Illinois across the year, which is 11.1% of the annual total.

Is June a good time to see monarch butterflies in Illinois?+

June is the 4th busiest month. It is workable, though August and July is the stronger window for a reliable sighting.

What month is best for monarch butterflies in Illinois?+

August is the single busiest month, with the broader peak running through August, July and September, based on 15,827 verified observations.

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

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