WhenToBird

Bubo virginianus · Strigidae

When Do Great Horned Owls Arrive in Colorado?

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

Great Horned Owls reach Colorado in late July, are common by the second week of August, peak in early May (5.2% of checklists), and most are gone by early June.

When to look

First arrivalsJul 22-31late July
Common byAug 8-14the second week of August
PeakMay 1-7early May
Most gone byJun 1-7early June

Best: early May. First arrivals late July; most are gone by early June. Peak: on about 5.2% of Colorado checklists.

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

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

0%2%4%6%Jan 1-7: 3.0% of 32254 checklistsJan 8-14: 2.7% of 23278 checklistsJan 15-21: 2.9% of 22933 checklistsJan 22-31: 3.2% of 30856 checklistsFeb 1-7: 3.5% of 21464 checklistsFeb 8-14: 3.0% of 22910 checklistsFeb 15-21: 2.8% of 28739 checklistsFeb 22-28: 3.5% of 21833 checklistsMar 1-7: 4.0% of 23066 checklistsMar 8-14: 4.0% of 23783 checklistsMar 15-21: 4.5% of 24797 checklistsMar 22-31: 4.2% of 38439 checklistsApr 1-7: 4.7% of 31676 checklistsApr 8-14: 4.4% of 35092 checklistsApr 15-21: 4.7% of 36778 checklistsApr 22-30: 5.1% of 50885 checklistsMay 1-7: 5.6% of 44186 checklistsMay 8-14: 5.0% of 49011 checklistsMay 15-21: 4.3% of 40784 checklistsMay 22-31: 2.9% of 53073 checklistsJun 1-7: 1.9% of 32432 checklistsJun 8-14: 1.8% of 29978 checklistsJun 15-21: 1.4% of 29457 checklistsJun 22-30: 1.3% of 36072 checklistsJul 1-7: 1.2% of 28857 checklistsJul 8-14: 1.5% of 27224 checklistsJul 15-21: 1.3% of 27629 checklistsJul 22-31: 1.6% of 37318 checklistsAug 1-7: 1.9% of 25893 checklistsAug 8-14: 2.3% of 24870 checklistsAug 15-21: 2.6% of 24035 checklistsAug 22-31: 2.7% of 35691 checklistsSep 1-7: 3.2% of 27068 checklistsSep 8-14: 3.1% of 26709 checklistsSep 15-21: 3.1% of 26098 checklistsSep 22-30: 3.1% of 31550 checklistsOct 1-7: 2.8% of 24110 checklistsOct 8-14: 2.5% of 23352 checklistsOct 15-21: 2.4% of 21895 checklistsOct 22-31: 2.4% of 28319 checklistsNov 1-7: 2.3% of 21698 checklistsNov 8-14: 2.1% of 21061 checklistsNov 15-21: 2.5% of 19855 checklistsNov 22-30: 2.2% of 25798 checklistsDec 1-7: 2.6% of 18626 checklistsDec 8-14: 3.1% of 19004 checklistsDec 15-21: 3.6% of 23103 checklistsDec 22-31: 2.8% of 30802 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 Colorado 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 Colorado

Best counties

Share of checklists at the peak
  1. Kiowa CountyBest early January · 17 checklists that week, 3,854 in all22%
  2. Washington CountyBest late January · 12 checklists that week, 2,511 in all19%
  3. Baca CountyBest early October · 50 checklists that week, 3,209 in all18%
  4. Yuma CountyBest mid April · 210 checklists that week, 3,844 in all18%
  5. Lincoln CountyBest the second week of May · 129 checklists that week, 2,707 in all17%
  6. Otero CountyBest the second week of January · 48 checklists that week, 4,404 in all17%

Best spots

Share of checklists at the peak
  1. Dancing Willows ParkJefferson County, best late April · 28 checklists that week, 331 in all70%
  2. Verbena ParkDenver County, best mid April · 20 checklists that week, 1,299 in all67%
  3. Chico BasinPueblo County, best late August · 30 checklists that week, 963 in all60%
  4. Bear Creek GreenbeltJefferson County, best mid April · 80 checklists that week, 3,759 in all58%

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

Best time of day

In Colorado, the Great Horned Owl is most often listed on checklists started between 5 and 7 pm (4.7% of those checklists).

0%2%4%6%12 am: too few checklists (512) to judge1 am: too few checklists (468) to judge2 am: too few checklists (513) to judge3 am: too few checklists (656) to judge4 am: too few checklists (1918) to judge5 am: too few checklists (16045) to judge6 am: 5.5% of 71991 checklists7 am: 2.8% of 159189 checklists8 am: 2.7% of 177206 checklists9 am: 2.3% of 165269 checklists10 am: 2.1% of 141029 checklists11 am: 2.1% of 115283 checklists12 pm: 1.9% of 96068 checklists1 pm: 2.1% of 89512 checklists2 pm: 2.1% of 86319 checklists3 pm: 2.6% of 82496 checklists4 pm: 3.6% of 71648 checklists5 pm: 4.4% of 52445 checklists6 pm: 5.2% of 40199 checklists7 pm: too few checklists (24246) to judge8 pm: too few checklists (7986) to judge9 pm: too few checklists (2004) to judge10 pm: too few checklists (888) to judge11 pm: too few checklists (450) 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
January3.0%2.7%2.9%3.2%
February3.5%3.0%2.8%3.5%
March4.0%4.0%4.5%4.2%
April4.7%4.4%4.7%5.1%
May5.6%5.0%4.3%2.9%
June1.9%1.8%1.4%1.3%
July1.2%1.5%1.3%1.6%
August1.9%2.3%2.6%2.7%
September3.2%3.1%3.1%3.1%
October2.8%2.5%2.4%2.4%
November2.3%2.1%2.5%2.2%
December2.6%3.1%3.6%2.8%

Neighboring states

  • Wyoming: arrives late July, in the same week than Colorado
  • New Mexico: year-round, peaks early May
  • Utah: year-round, peaks late January
  • Nebraska: year-round, peaks mid December

Common questions

When do Great Horned Owls arrive in Colorado?
Great Horned Owls reach Colorado in late July, are common by the second week of August, peak in early May (5.2% of checklists), and most are gone by early June.
When do Great Horned Owls leave Colorado?
Most Great Horned Owls have left Colorado by early June, when reports fall below half their usual rate. Stragglers are still reported until the second week of June.
When is the best time to see a Great Horned Owl in Colorado?
The Great Horned Owl is reported most often in early May, on about 5.2% of Colorado checklists.
Where in Colorado are Great Horned Owls seen most often?
By county, Kiowa County, Washington County, and Baca County have the highest peak reporting rates for the Great Horned Owl (counties with at least 200 checklists).