WhenToBird

Strix varia · Strigidae

When Do Barred Owls Arrive in Illinois?

Adult Barred Owl
Photo: David Bird, CC0 1.0 via iNaturalist

Barred Owls arrive in Illinois in the second week of December, peak in early May (2.5% of checklists), and most are gone by early June.

When to look

First arrivalsDec 8-14the second week of December
Common byDec 8-14the second week of December
PeakMay 1-7early May
Most gone byJun 1-7early June

Best: early May. First arrivals the second week of December; most are gone by early June. Peak: on about 2.5% of Illinois checklists.

  1. Jancommon
  2. Febcommon
  3. Marcommon
  4. Aprpeak season
  5. Maypeak season
  6. Juncommon
  7. Julcommon
  8. Augcommon
  9. Sepcommon
  10. Octcommon
  11. Novcommon
  12. Deccommon

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

0%1%2%3%Jan 1-7: 1.4% of 29700 checklistsJan 8-14: 1.2% of 20189 checklistsJan 15-21: 0.9% of 19784 checklistsJan 22-31: 1.3% of 26641 checklistsFeb 1-7: 1.7% of 20478 checklistsFeb 8-14: 1.5% of 21967 checklistsFeb 15-21: 1.4% of 28735 checklistsFeb 22-28: 1.8% of 24223 checklistsMar 1-7: 1.7% of 26775 checklistsMar 8-14: 1.6% of 27579 checklistsMar 15-21: 1.6% of 27193 checklistsMar 22-31: 1.7% of 42278 checklistsApr 1-7: 1.8% of 34579 checklistsApr 8-14: 2.2% of 38290 checklistsApr 15-21: 2.3% of 39261 checklistsApr 22-30: 2.4% of 59584 checklistsMay 1-7: 2.6% of 60485 checklistsMay 8-14: 2.4% of 59647 checklistsMay 15-21: 1.7% of 43173 checklistsMay 22-31: 1.4% of 47913 checklistsJun 1-7: 1.1% of 31151 checklistsJun 8-14: 1.2% of 27692 checklistsJun 15-21: 1.1% of 23983 checklistsJun 22-30: 1.0% of 28448 checklistsJul 1-7: 1.0% of 21273 checklistsJul 8-14: 1.0% of 19284 checklistsJul 15-21: 0.9% of 17712 checklistsJul 22-31: 0.9% of 24500 checklistsAug 1-7: 1.0% of 18498 checklistsAug 8-14: 1.2% of 19331 checklistsAug 15-21: 1.2% of 19983 checklistsAug 22-31: 1.5% of 31892 checklistsSep 1-7: 1.6% of 26396 checklistsSep 8-14: 1.7% of 25011 checklistsSep 15-21: 2.0% of 23597 checklistsSep 22-30: 1.5% of 30638 checklistsOct 1-7: 1.5% of 23949 checklistsOct 8-14: 1.3% of 24412 checklistsOct 15-21: 1.0% of 22359 checklistsOct 22-31: 1.1% of 29794 checklistsNov 1-7: 1.2% of 21877 checklistsNov 8-14: 0.9% of 19742 checklistsNov 15-21: 1.1% of 18989 checklistsNov 22-30: 0.9% of 23905 checklistsDec 1-7: 0.9% of 16935 checklistsDec 8-14: 1.0% of 16687 checklistsDec 15-21: 1.9% of 20931 checklistsDec 22-31: 1.5% of 29011 checklistsJanFebMarAprMayJunJulAugSepOctNovDec
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
Second week of November

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.

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Where in Illinois

Best counties

Share of checklists at the peak
  1. Putnam CountyBest the second week of January · 18 checklists that week, 3,333 in all34%
  2. Monroe CountyBest early October · 43 checklists that week, 2,547 in all25%
  3. Edwards CountyBest late August · 15 checklists that week, 797 in all25%
  4. Brown CountyBest mid May · 13 checklists that week, 403 in all24%
  5. Johnson CountyBest early June · 91 checklists that week, 2,856 in all24%
  6. Warren CountyBest late July · 18 checklists that week, 658 in all21%

Best spots

Share of checklists at the peak
  1. Robert Allerton ParkPiatt County, best the second week of February · 23 checklists that week, 1,122 in all49%
  2. Iroquois County State Fish and Wildlife AreaIroquois County, best the second week of June · 20 checklists that week, 122 in all43%
  3. Centennial Park (Wolf Branch)St. Clair County, best the second week of April · 23 checklists that week, 237 in all41%
  4. Ferne Clyffe LakeJohnson County, best late April · 61 checklists that week, 417 in all38%
  5. Linne WoodsCook County, best the second week of February · 23 checklists that week, 1,012 in all38%

Busy spots report more of everything; compare the checklist counts before you drive anywhere.

Best time of day

In Illinois, the Barred Owl is most often listed on checklists started between 5 and 7 pm (2.5% of those checklists).

0%1%2%3%12 am: too few checklists (484) to judge1 am: too few checklists (631) to judge2 am: too few checklists (485) to judge3 am: too few checklists (610) to judge4 am: too few checklists (2321) to judge5 am: too few checklists (23536) to judge6 am: 2.2% of 95511 checklists7 am: 1.6% of 164584 checklists8 am: 1.3% of 163654 checklists9 am: 1.0% of 141804 checklists10 am: 0.9% of 122882 checklists11 am: 0.8% of 100640 checklists12 pm: 0.8% of 89894 checklists1 pm: 1.0% of 82729 checklists2 pm: 1.3% of 79801 checklists3 pm: 1.5% of 82169 checklists4 pm: 1.9% of 75124 checklists5 pm: 2.4% of 57708 checklists6 pm: 2.8% of 41843 checklists7 pm: too few checklists (20943) to judge8 pm: too few checklists (6131) to judge9 pm: too few checklists (1677) to judge10 pm: too few checklists (843) to judge11 pm: too few checklists (448) to judge12a3a6a9a12p3p6p9p
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
MonthDays 1-78-1415-2122-end
January1.4%1.2%0.9%1.3%
February1.7%1.5%1.4%1.8%
March1.7%1.6%1.6%1.7%
April1.8%2.2%2.3%2.4%
May2.6%2.4%1.7%1.4%
June1.1%1.2%1.1%1.0%
July1.0%1.0%0.9%0.9%
August1.0%1.2%1.2%1.5%
September1.6%1.7%2.0%1.5%
October1.5%1.3%1.0%1.1%
November1.2%0.9%1.1%0.9%
December0.9%1.0%1.9%1.5%

Neighboring states

  • Indiana: arrives early December, 1 week earlier than Illinois
  • Wisconsin: arrives late January, 6 weeks later than Illinois
  • Michigan: arrives the second week of December, in the same week than Illinois
  • Iowa: arrives early April, 15 weeks later than Illinois

Common questions

When do Barred Owls arrive in Illinois?
Barred Owls arrive in Illinois in the second week of December, peak in early May (2.5% of checklists), and most are gone by early June.
When do Barred Owls leave Illinois?
Most Barred Owls have left Illinois by early June, when reports fall below half their usual rate. Stragglers are still reported until early July.
When is the best time to see a Barred Owl in Illinois?
The Barred Owl is reported most often in early May, on about 2.5% of Illinois checklists.
Where in Illinois are Barred Owls seen most often?
By county, Putnam County, Monroe County, and Edwards County have the highest peak reporting rates for the Barred Owl (counties with at least 200 checklists).