WhenToBird

Bubo virginianus · Strigidae

When Do Great Horned Owls Arrive in Idaho?

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

Great Horned Owls are winter birds in Idaho: the first arrive in late June, they are common by mid August, peak in late March (4.4% of checklists), and most are gone by late May.

When to look

First arrivalsJun 22-30late June
Common byAug 15-21mid August
PeakMar 22-31late March
Most gone byMay 22-31late May

Best: late March. First arrivals late June; most are gone by late May. Peak: on about 4.4% of Idaho checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Juncommon
  7. Julcommon
  8. Augcommon
  9. Seppeak season
  10. Octcommon
  11. Novpeak season
  12. Decpeak season

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

0%2%4%6%Jan 1-7: 3.7% of 9357 checklistsJan 8-14: 3.9% of 6408 checklistsJan 15-21: 3.6% of 6358 checklistsJan 22-31: 3.8% of 8601 checklistsFeb 1-7: 4.5% of 5611 checklistsFeb 8-14: 4.4% of 6090 checklistsFeb 15-21: 4.0% of 7973 checklistsFeb 22-28: 3.9% of 5866 checklistsMar 1-7: 4.7% of 6144 checklistsMar 8-14: 3.9% of 6456 checklistsMar 15-21: 4.6% of 6786 checklistsMar 22-31: 4.3% of 9539 checklistsApr 1-7: 4.5% of 7202 checklistsApr 8-14: 4.0% of 7608 checklistsApr 15-21: 4.2% of 8069 checklistsApr 22-30: 4.0% of 10973 checklistsMay 1-7: 4.1% of 9481 checklistsMay 8-14: 3.6% of 11318 checklistsMay 15-21: 3.3% of 9141 checklistsMay 22-31: 2.9% of 13984 checklistsJun 1-7: 2.2% of 8897 checklistsJun 8-14: 1.5% of 8504 checklistsJun 15-21: 1.9% of 8078 checklistsJun 22-30: 1.8% of 9665 checklistsJul 1-7: 2.2% of 7144 checklistsJul 8-14: 1.8% of 6557 checklistsJul 15-21: 2.0% of 6430 checklistsJul 22-31: 2.0% of 8696 checklistsAug 1-7: 2.2% of 5896 checklistsAug 8-14: 2.3% of 5643 checklistsAug 15-21: 2.6% of 6151 checklistsAug 22-31: 2.8% of 7863 checklistsSep 1-7: 3.3% of 5769 checklistsSep 8-14: 3.4% of 5646 checklistsSep 15-21: 3.4% of 5460 checklistsSep 22-30: 3.1% of 6363 checklistsOct 1-7: 3.1% of 4980 checklistsOct 8-14: 2.3% of 5096 checklistsOct 15-21: 2.9% of 4878 checklistsOct 22-31: 2.5% of 6426 checklistsNov 1-7: 3.1% of 4822 checklistsNov 8-14: 2.9% of 4999 checklistsNov 15-21: 3.5% of 4601 checklistsNov 22-30: 3.1% of 6027 checklistsDec 1-7: 3.5% of 4180 checklistsDec 8-14: 3.6% of 4775 checklistsDec 15-21: 3.8% of 6522 checklistsDec 22-31: 4.2% of 7792 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 Idaho 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.

Embed this map on your site

Where in Idaho

Best counties

Share of checklists at the peak
  1. Jefferson CountyBest early September · 124 checklists that week, 5,319 in all28%
  2. Adams CountyBest mid December · 97 checklists that week, 5,826 in all21%
  3. Butte CountyBest mid February · 16 checklists that week, 1,276 in all19%
  4. Oneida CountyBest early November · 12 checklists that week, 1,750 in all16%
  5. Gem CountyBest the second week of January · 133 checklists that week, 8,320 in all14%
  6. Lemhi CountyBest mid October · 52 checklists that week, 6,242 in all13%

Best spots

Share of checklists at the peak
  1. Market Lake Wildlife Management Area (northwest)Jefferson County, best late May · 21 checklists that week, 135 in all83%
  2. Hulls Gulch Reserve (east)Ada County, best early May · 26 checklists that week, 441 in all56%
  3. Market Lake Wildlife Management AreaJefferson County, best late May · 68 checklists that week, 697 in all45%
  4. Camas National Wildlife RefugeJefferson County, best late August · 40 checklists that week, 540 in all43%
  5. Barber ParkAda County, best late April · 25 checklists that week, 1,607 in all38%

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

Best time of day

In Idaho, the Great Horned Owl is most often listed on checklists started between 6 and 8 pm (4.9% of those checklists).

0%2%4%6%8%12 am: too few checklists (180) to judge1 am: too few checklists (176) to judge2 am: too few checklists (169) to judge3 am: too few checklists (164) to judge4 am: too few checklists (450) to judge5 am: too few checklists (2270) to judge6 am: 6.3% of 9122 checklists7 am: 4.0% of 22204 checklists8 am: 3.5% of 38672 checklists9 am: 2.9% of 38930 checklists10 am: 2.7% of 37338 checklists11 am: 2.0% of 33508 checklists12 pm: 1.9% of 28544 checklists1 pm: 2.1% of 25774 checklists2 pm: 2.3% of 24296 checklists3 pm: 2.4% of 21784 checklists4 pm: 3.2% of 19051 checklists5 pm: 4.0% of 14150 checklists6 pm: 4.6% of 10014 checklists7 pm: 5.4% of 7495 checklists8 pm: too few checklists (4352) to judge9 pm: too few checklists (1449) to judge10 pm: too few checklists (525) to judge11 pm: too few checklists (208) 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
January3.7%3.9%3.6%3.8%
February4.5%4.4%4.0%3.9%
March4.7%3.9%4.6%4.3%
April4.5%4.0%4.2%4.0%
May4.1%3.6%3.3%2.9%
June2.2%1.5%1.9%1.8%
July2.2%1.8%2.0%2.0%
August2.2%2.3%2.6%2.8%
September3.3%3.4%3.4%3.1%
October3.1%2.3%2.9%2.5%
November3.1%2.9%3.5%3.1%
December3.5%3.6%3.8%4.2%

Neighboring states

  • Montana: arrives mid July, 3 weeks later than Idaho
  • Utah: year-round, peaks late January
  • Oregon: year-round, peaks late May
  • Washington: year-round, peaks early March

Common questions

When do Great Horned Owls arrive in Idaho?
Great Horned Owls are winter birds in Idaho: the first arrive in late June, they are common by mid August, peak in late March (4.4% of checklists), and most are gone by late May.
When do Great Horned Owls leave Idaho?
Most Great Horned Owls have left Idaho by late May, when reports fall below half their usual rate. Stragglers are still reported until early June.
When is the best time to see a Great Horned Owl in Idaho?
The Great Horned Owl is reported most often in late March, on about 4.4% of Idaho checklists.
Where in Idaho are Great Horned Owls seen most often?
By county, Jefferson County, Adams County, and Butte County have the highest peak reporting rates for the Great Horned Owl (counties with at least 200 checklists).