WhenToBird

2 oriole species in Illinois

When Do Orioles Arrive in Illinois?

Adult male Baltimore Oriole
Photo: Daughter Dad, CC BY 4.0 via iNaturalist

Baltimore Orioles and Orchard Orioles are the orioles you are most likely to see in Illinois. Baltimore Orioles reach Illinois in mid April, are common by late April, peak in mid May (45% of checklists), and most are gone by late August.

Orioles here are the birds (Baltimore, Orchard, Bullock's and relatives), not the baseball team.

When to look

First arrivalsApr 15-21mid April
Common byApr 22-30late April
PeakMay 15-21mid May
Most gone byAug 22-31late August

Best: mid May. First arrivals mid April; most are gone by late August. Peak: on about 45% of Illinois checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Apruncommon
  5. Maypeak season
  6. Juncommon
  7. Juluncommon
  8. Auguncommon
  9. Sepuncommon
  10. Octnot usually seen
  11. Novnot usually seen
  12. Decnot usually seen

Darker months: more checklists report it. Outlined: peak month.

Orioles in Illinois, species by species

SpeciesFirst arrivalsCommon byPeakMost gone byPeak %
Baltimore OrioleApr 15-21Apr 22-30May 15-21Aug 22-3145%
Orchard OrioleApr 22-30May 1-7May 15-21Jul 8-149.5%
0%20%40%60%Baltimore OrioleOrchard OrioleJanFebMarAprMayJunJulAugSepOctNovDec
  • Baltimore Oriole
  • Orchard Oriole
Share of complete checklists reporting each species, by week (4 per month). Gaps: fewer than 10 checklists that week.

Frequency is the share of complete checklists in Illinois that listed the bird, 2016–2025. It is not a head count, and it follows where and when people go birding. How to read it.

Where in Illinois

Best counties for Baltimore Oriole

Share of checklists at the peak
  1. Whiteside CountyBest late May · 109 checklists that week, 4,111 in all74%
  2. Putnam CountyBest late May · 76 checklists that week, 3,333 in all72%
  3. Schuyler CountyBest the second week of May · 27 checklists that week, 617 in all70%
  4. Jo Daviess CountyBest mid May · 81 checklists that week, 2,760 in all60%
  5. Carroll CountyBest mid May · 137 checklists that week, 4,152 in all59%
  6. DuPage CountyBest mid May · 4068 checklists that week, 134,332 in all59%

Common questions

When do orioles arrive in Illinois?
Baltimore Orioles reach Illinois in mid April, are common by late April, peak in mid May (45% of checklists), and most are gone by late August.
When do orioles leave Illinois?
Most Baltimore Orioles have left Illinois by late August, when reports fall below half their usual rate. Stragglers are still reported until the second week of September.
When is the best time to see orioles in Illinois?
The Baltimore Oriole is reported most often in mid May, on about 45% of Illinois checklists.
Which orioles are in Illinois?
Baltimore Oriole and Orchard Oriole are reported regularly; the Baltimore Oriole is the most common.