WhenToBird

Bubo virginianus · Strigidae

When Do Great Horned Owls Arrive in Pennsylvania?

Adult Great Horned Owl
Photo: Michael Warner, CC BY 4.0 via iNaturalist

Great Horned Owls are winter birds in Pennsylvania: they arrive in late August, peak in late December (1.6% of checklists), and most are gone by mid May.

When to look

First arrivalsAug 22-31late August
Common byAug 22-31late August
PeakDec 22-31late December
Most gone byMay 15-21mid May

Best: late December. First arrivals late August; most are gone by mid May. Peak: on about 1.6% of Pennsylvania checklists.

  1. Janpeak season
  2. Febcommon
  3. Marcommon
  4. Aprcommon
  5. Maycommon
  6. Jununcommon
  7. Juluncommon
  8. Auguncommon
  9. Sepcommon
  10. Octcommon
  11. Novcommon
  12. Decpeak season

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

0%0.5%1%1.5%2%Jan 1-7: 1.4% of 47145 checklistsJan 8-14: 1.3% of 35840 checklistsJan 15-21: 1.2% of 35423 checklistsJan 22-31: 1.1% of 49126 checklistsFeb 1-7: 1.2% of 36366 checklistsFeb 8-14: 1.1% of 42248 checklistsFeb 15-21: 0.9% of 55888 checklistsFeb 22-28: 1.2% of 42050 checklistsMar 1-7: 1.1% of 42709 checklistsMar 8-14: 1.3% of 43985 checklistsMar 15-21: 1.1% of 44547 checklistsMar 22-31: 1.1% of 66940 checklistsApr 1-7: 1.2% of 51147 checklistsApr 8-14: 1.2% of 54868 checklistsApr 15-21: 1.2% of 57252 checklistsApr 22-30: 1.0% of 81727 checklistsMay 1-7: 0.9% of 76472 checklistsMay 8-14: 0.7% of 79341 checklistsMay 15-21: 0.6% of 61724 checklistsMay 22-31: 0.4% of 70722 checklistsJun 1-7: 0.3% of 45652 checklistsJun 8-14: 0.3% of 41810 checklistsJun 15-21: 0.3% of 38973 checklistsJun 22-30: 0.3% of 44255 checklistsJul 1-7: 0.4% of 34822 checklistsJul 8-14: 0.3% of 31104 checklistsJul 15-21: 0.4% of 29262 checklistsJul 22-31: 0.4% of 41436 checklistsAug 1-7: 0.4% of 29189 checklistsAug 8-14: 0.4% of 28840 checklistsAug 15-21: 0.5% of 29948 checklistsAug 22-31: 0.5% of 48235 checklistsSep 1-7: 0.8% of 37175 checklistsSep 8-14: 0.8% of 36527 checklistsSep 15-21: 0.9% of 37261 checklistsSep 22-30: 0.9% of 43583 checklistsOct 1-7: 1.1% of 35352 checklistsOct 8-14: 1.2% of 35560 checklistsOct 15-21: 1.0% of 33119 checklistsOct 22-31: 1.0% of 44654 checklistsNov 1-7: 1.0% of 32965 checklistsNov 8-14: 1.0% of 31305 checklistsNov 15-21: 1.0% of 29471 checklistsNov 22-30: 1.1% of 38642 checklistsDec 1-7: 1.2% of 28779 checklistsDec 8-14: 1.3% of 29486 checklistsDec 15-21: 1.8% of 37465 checklistsDec 22-31: 1.6% of 50651 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 Pennsylvania 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 Pennsylvania

Best counties

Share of checklists at the peak
  1. Lancaster CountyBest the second week of April · 2659 checklists that week, 97,892 in all5.7%
  2. Snyder CountyBest late December · 70 checklists that week, 5,676 in all4.0%
  3. Wyoming CountyBest mid January · 50 checklists that week, 6,156 in all4.0%
  4. Blair CountyBest late August · 234 checklists that week, 13,387 in all3.8%
  5. Montour CountyBest the second week of April · 198 checklists that week, 6,082 in all3.8%
  6. Fulton CountyBest mid December · 162 checklists that week, 7,004 in all3.5%

Best spots

Share of checklists at the peak
  1. Little Chickies ParkLancaster County, best late March · 25 checklists that week, 169 in all98%
  2. Panther Hollow Lake (west)Allegheny County, best the second week of March · 25 checklists that week, 543 in all70%
  3. Kutztown Elementary SchoolBerks County, best the second week of April · 22 checklists that week, 301 in all70%
  4. Houston ParkDelaware County, best late April · 20 checklists that week, 241 in all60%
  5. Lederer ParkCentre County, best early April · 22 checklists that week, 715 in all50%
  6. Farmingdale TrailsLancaster County, best mid January · 75 checklists that week, 6,512 in all49%

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

Best time of day

In Pennsylvania, the Great Horned Owl is most often listed on checklists started between 6 and 8 pm (1.9% of those checklists).

0%1%2%3%12 am: too few checklists (1558) to judge1 am: too few checklists (1136) to judge2 am: too few checklists (839) to judge3 am: too few checklists (842) to judge4 am: too few checklists (2550) to judge5 am: too few checklists (18294) to judge6 am: 2.2% of 92903 checklists7 am: 0.8% of 241233 checklists8 am: 0.5% of 271994 checklists9 am: 0.4% of 236842 checklists10 am: 0.4% of 199508 checklists11 am: 0.4% of 161893 checklists12 pm: 0.4% of 143945 checklists1 pm: 0.4% of 134352 checklists2 pm: 0.5% of 129692 checklists3 pm: 0.7% of 126132 checklists4 pm: 1.3% of 115055 checklists5 pm: 1.7% of 90719 checklists6 pm: 1.7% of 67534 checklists7 pm: 2.2% of 43004 checklists8 pm: too few checklists (13966) to judge9 pm: too few checklists (3913) to judge10 pm: too few checklists (1989) to judge11 pm: too few checklists (1146) 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%1.3%1.2%1.1%
February1.2%1.1%0.9%1.2%
March1.1%1.3%1.1%1.1%
April1.2%1.2%1.2%1.0%
May0.9%0.7%0.6%0.4%
June0.3%0.3%0.3%0.3%
July0.4%0.3%0.4%0.4%
August0.4%0.4%0.5%0.5%
September0.8%0.8%0.9%0.9%
October1.1%1.2%1.0%1.0%
November1.0%1.0%1.0%1.1%
December1.2%1.3%1.8%1.6%

Neighboring states

  • Maryland: arrives the second week of August, 2 weeks earlier than Pennsylvania
  • Delaware: arrives mid August, 1 week earlier than Pennsylvania
  • New Jersey: arrives mid August, 1 week earlier than Pennsylvania
  • New York: arrives mid August, 1 week earlier than Pennsylvania

Common questions

When do Great Horned Owls arrive in Pennsylvania?
Great Horned Owls are winter birds in Pennsylvania: they arrive in late August, peak in late December (1.6% of checklists), and most are gone by mid May.
When do Great Horned Owls leave Pennsylvania?
Most Great Horned Owls have left Pennsylvania by mid May, when reports fall below half their usual rate.
When is the best time to see a Great Horned Owl in Pennsylvania?
The Great Horned Owl is reported most often in late December, on about 1.6% of Pennsylvania checklists.
Where in Pennsylvania are Great Horned Owls seen most often?
By county, Lancaster County, Snyder County, and Wyoming County have the highest peak reporting rates for the Great Horned Owl (counties with at least 200 checklists).