Orange-crowned Warblers are winter birds in Illinois: they arrive in early September, peak in the second week of October (7.3% of checklists), and most are gone by the second week of January.
When to look
First arrivalsSep 1-7early September
Common bySep 1-7early September
PeakOct 8-14the second week of October
Most gone byJan 8-14the second week of January
Best: the second week of October. First arrivals early September; most are gone by the second week of January. Peak: on about 7.3% of Illinois checklists.
Jannot usually seen
Febnot usually seen
Marnot usually seen
Aprcommon
Maycommon
Junnot usually seen
Julnot usually seen
Augnot usually seen
Sepcommon
Octpeak season
Novuncommon
Decnot usually seen
Darker months: more checklists report it. Outlined: peak month.
Share of complete checklists reporting it, by week (4 per month). Grey bars: fewer than 10 checklists, not counted.
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.
JanFebMarAprMayJunJulAugSepOctNovDec
today
0%few checklistsno data
Each county is shaded by the share of complete checklists there that listed the bird, blended with the weeks either side. Darker is more often. It follows where people watch birds, not how many birds there are. How to read it.
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Illinois, the Orange-crowned Warbler is most often listed on checklists started between 6 and 8 am (2.1% of those checklists).
Share of checklists started in each local hour that reported it. It reflects when people go birding as well as when birds are active. Grey hours have too few checklists (under 2% of the state’s, or under 200) to judge.Week-by-week table
Month
Days 1-7
8-14
15-21
22-end
January
0.2%
0.1%
0.1%
0.1%
February
0.1%
0.1%
0.1%
0.1%
March
0.1%
0.1%
0.1%
0.1%
April
0.1%
0.1%
0.9%
3.6%
May
4.6%
4.1%
2.3%
0.3%
June
0%
0.1%
0%
0%
July
0%
0%
0%
0%
August
0%
0%
0%
0.1%
September
0.1%
0.2%
1.0%
3.2%
October
5.7%
7.5%
8.8%
5.1%
November
1.8%
0.7%
0.3%
0.2%
December
0.2%
0.1%
0.2%
0.2%
Neighboring states
Indiana: arrives the second week of September, 1 week later than Illinois
Wisconsin: arrives early September, in the same week than Illinois
Michigan: arrives the second week of September, 1 week later than Illinois
Iowa: arrives mid September, 2 weeks later than Illinois
Common questions
When do Orange-crowned Warblers arrive in Illinois?
Orange-crowned Warblers are winter birds in Illinois: they arrive in early September, peak in the second week of October (7.3% of checklists), and most are gone by the second week of January.
When do Orange-crowned Warblers leave Illinois?
Most Orange-crowned Warblers have left Illinois by the second week of January, when reports fall below half their usual rate.
When is the best time to see a Orange-crowned Warbler in Illinois?
The Orange-crowned Warbler is reported most often in the second week of October, on about 7.3% of Illinois checklists.
Where in Illinois are Orange-crowned Warblers seen most often?
By county, Wayne County, Warren County, and Perry County have the highest peak reporting rates for the Orange-crowned Warbler (counties with at least 200 checklists).