WhenToBird

Astur cooperii · Accipitridae

When Do Cooper's Hawks Arrive in Oregon?

Adult male Cooper's Hawk
Photo: Shirley Zundell, CC BY 4.0 via iNaturalist

Cooper's Hawks reach Oregon in late June, are common by late July, peak in late September (5.0% of checklists), and most are gone by early May.

When to look

First arrivalsJun 22-30late June
Common byJul 22-31late July
PeakSep 22-30late September
Most gone byMay 1-7early May

Best: late September. First arrivals late June; most are gone by early May. Peak: on about 5.0% of Oregon checklists.

  1. Janpeak season
  2. Febcommon
  3. Marcommon
  4. Aprcommon
  5. Maycommon
  6. Jununcommon
  7. Julcommon
  8. Augpeak season
  9. Seppeak season
  10. Octpeak season
  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 34973 checklistsJan 8-14: 3.4% of 26807 checklistsJan 15-21: 3.4% of 26567 checklistsJan 22-31: 3.2% of 36019 checklistsFeb 1-7: 3.3% of 24020 checklistsFeb 8-14: 3.0% of 25765 checklistsFeb 15-21: 3.2% of 31019 checklistsFeb 22-28: 2.6% of 24582 checklistsMar 1-7: 2.9% of 24834 checklistsMar 8-14: 3.1% of 24642 checklistsMar 15-21: 2.9% of 27420 checklistsMar 22-31: 3.3% of 39913 checklistsApr 1-7: 3.5% of 28817 checklistsApr 8-14: 3.7% of 31221 checklistsApr 15-21: 3.9% of 34402 checklistsApr 22-30: 3.6% of 47144 checklistsMay 1-7: 2.7% of 37716 checklistsMay 8-14: 2.4% of 39651 checklistsMay 15-21: 2.0% of 37496 checklistsMay 22-31: 1.7% of 56967 checklistsJun 1-7: 1.6% of 35893 checklistsJun 8-14: 1.7% of 31880 checklistsJun 15-21: 1.7% of 30942 checklistsJun 22-30: 1.8% of 38478 checklistsJul 1-7: 2.0% of 27409 checklistsJul 8-14: 2.3% of 25161 checklistsJul 15-21: 2.3% of 25473 checklistsJul 22-31: 2.7% of 33920 checklistsAug 1-7: 3.2% of 24310 checklistsAug 8-14: 3.6% of 23675 checklistsAug 15-21: 3.4% of 23623 checklistsAug 22-31: 3.8% of 33762 checklistsSep 1-7: 4.2% of 25120 checklistsSep 8-14: 4.2% of 24458 checklistsSep 15-21: 5.0% of 25528 checklistsSep 22-30: 5.1% of 31631 checklistsOct 1-7: 4.9% of 25498 checklistsOct 8-14: 4.5% of 25161 checklistsOct 15-21: 4.1% of 23701 checklistsOct 22-31: 3.8% of 30996 checklistsNov 1-7: 3.8% of 21089 checklistsNov 8-14: 4.0% of 21880 checklistsNov 15-21: 4.2% of 21501 checklistsNov 22-30: 4.0% of 28930 checklistsDec 1-7: 3.8% of 19807 checklistsDec 8-14: 4.1% of 21022 checklistsDec 15-21: 4.2% of 24817 checklistsDec 22-31: 4.1% of 37592 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 Oregon 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 Oregon

Best counties

Share of checklists at the peak
  1. Harney CountyBest the second week of January · 121 checklists that week, 40,943 in all18%
  2. Hood River CountyBest mid September · 220 checklists that week, 9,695 in all17%
  3. Wheeler CountyBest the second week of December · 25 checklists that week, 3,129 in all11%
  4. Jefferson CountyBest early October · 289 checklists that week, 11,014 in all11%
  5. Malheur CountyBest the second week of December · 31 checklists that week, 4,699 in all9.9%
  6. Washington CountyBest early October · 1869 checklists that week, 110,376 in all9.9%

Best spots

Share of checklists at the peak
  1. Fernhill ParkMultnomah County, best late July · 25 checklists that week, 542 in all80%
  2. Deschutes National Forest (north)Jefferson County, best late September · 28 checklists that week, 107 in all74%
  3. White River Segment BHood River County, best the second week of September · 58 checklists that week, 411 in all53%
  4. Happy Valley ParkClackamas County, best mid June · 24 checklists that week, 999 in all42%
  5. Fernhill WetlandsWashington County, best the second week of December · 93 checklists that week, 6,516 in all39%

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

Best time of day

In Oregon, the Cooper's Hawk is most often listed on checklists started between 7 and 9 am (4.3% of those checklists).

0%2%4%6%12 am: too few checklists (1505) to judge1 am: too few checklists (675) to judge2 am: too few checklists (626) to judge3 am: too few checklists (1641) to judge4 am: too few checklists (3696) to judge5 am: too few checklists (14524) to judge6 am: 3.1% of 50677 checklists7 am: 4.3% of 125347 checklists8 am: 4.3% of 163668 checklists9 am: 4.1% of 160351 checklists10 am: 3.6% of 148940 checklists11 am: 3.2% of 124743 checklists12 pm: 3.0% of 112537 checklists1 pm: 2.9% of 98999 checklists2 pm: 2.9% of 94690 checklists3 pm: 2.8% of 87923 checklists4 pm: 2.2% of 75235 checklists5 pm: 2.0% of 54504 checklists6 pm: 2.0% of 40469 checklists7 pm: 1.7% of 33675 checklists8 pm: too few checklists (18715) to judge9 pm: too few checklists (5839) to judge10 pm: too few checklists (2704) to judge11 pm: too few checklists (1549) 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%3.4%3.4%3.2%
February3.3%3.0%3.2%2.6%
March2.9%3.1%2.9%3.3%
April3.5%3.7%3.9%3.6%
May2.7%2.4%2.0%1.7%
June1.6%1.7%1.7%1.8%
July2.0%2.3%2.3%2.7%
August3.2%3.6%3.4%3.8%
September4.2%4.2%5.0%5.1%
October4.9%4.5%4.1%3.8%
November3.8%4.0%4.2%4.0%
December3.8%4.1%4.2%4.1%

Neighboring states

  • Washington: year-round, peaks early October
  • Idaho: arrives early September, 9 weeks later than Oregon
  • Nevada: arrives early September, 9 weeks later than Oregon
  • California: year-round, peaks late September

Common questions

When do Cooper's Hawks arrive in Oregon?
Cooper's Hawks reach Oregon in late June, are common by late July, peak in late September (5.0% of checklists), and most are gone by early May.
When do Cooper's Hawks leave Oregon?
Most Cooper's Hawks have left Oregon by early May, when reports fall below half their usual rate. Stragglers are still reported until mid May.
When is the best time to see a Cooper's Hawk in Oregon?
The Cooper's Hawk is reported most often in late September, on about 5.0% of Oregon checklists.
Where in Oregon are Cooper's Hawks seen most often?
By county, Harney County, Hood River County, and Wheeler County have the highest peak reporting rates for the Cooper's Hawk (counties with at least 200 checklists).