American Robins are in Illinois all year, but most are here in summer: numbers build from the second week of March, peak in mid May (76% of checklists), and fall back by mid August. In the quietest week (the second week of January) they are still on about 21% of checklists.
When to look
Numbers buildMar 8-14the second week of March
PeakMay 15-21mid May
Fall back byAug 15-21mid August
FewestJan 8-14the second week of January
Best: mid May. Here all year; numbers build from the second week of March and fall back by mid August. Peak: on about 76% of Illinois checklists.
Januncommon
Febcommon
Marpeak season
Aprpeak season
Maypeak season
Junpeak season
Julpeak season
Augpeak season
Sepcommon
Octcommon
Novcommon
Decuncommon
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.
Riis (Jacob)Cook County, best late July · 22 checklists that week, 914 in all100%
Perry Farm ParkKankakee County, best late March · 26 checklists that week, 810 in all100%
Salt Creek ParkDuPage County, best late May · 23 checklists that week, 565 in all100%
Lake Storey ParkKnox County, best early May · 20 checklists that week, 292 in all100%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Illinois, the American Robin is most often listed on checklists started between 6 and 8 am (66% 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
21%
21%
21%
22%
February
23%
22%
23%
33%
March
46%
58%
68%
73%
April
74%
76%
75%
74%
May
75%
76%
76%
76%
June
70%
69%
71%
70%
July
73%
71%
71%
67%
August
60%
53%
49%
47%
September
47%
47%
49%
50%
October
53%
55%
55%
52%
November
48%
39%
34%
30%
December
26%
26%
27%
26%
Neighboring states
Indiana: arrives the second week of March, in the same week than Illinois
Wisconsin: arrives the second week of March, in the same week than Illinois
Michigan: arrives the second week of March, in the same week than Illinois
American Robins are in Illinois all year, but most are here in summer: numbers build from the second week of March, peak in mid May (76% of checklists), and fall back by mid August. In the quietest week (the second week of January) they are still on about 21% of checklists.
When do American Robins leave Illinois?
American Robins never fully leave Illinois: numbers fall back below half their usual rate by mid August, but some are still reported in every week, about 21% of checklists at the low.
When is the best time to see a American Robin in Illinois?
The American Robin is reported most often in mid May, on about 76% of Illinois checklists.
Where in Illinois are American Robins seen most often?
By county, Greene County, Macoupin County, and Livingston County have the highest peak reporting rates for the American Robin (counties with at least 200 checklists).