WhenToBird

Astur cooperii · Accipitridae

When Do Cooper's Hawks Arrive in Michigan?

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

Cooper's Hawks reach Michigan in the second week of July, are common by the second week of August, peak in late September (5.6% of checklists), and most are gone by the second week of May.

When to look

First arrivalsJul 8-14the second week of July
Common byAug 8-14the second week of August
PeakSep 22-30late September
Most gone byMay 8-14the second week of May

Best: late September. First arrivals the second week of July; most are gone by the second week of May. Peak: on about 5.6% of Michigan checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marcommon
  4. Aprpeak season
  5. Maycommon
  6. Jununcommon
  7. Julcommon
  8. Augcommon
  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: 4.6% of 38160 checklistsJan 8-14: 4.8% of 24696 checklistsJan 15-21: 4.8% of 23771 checklistsJan 22-31: 4.7% of 31347 checklistsFeb 1-7: 4.7% of 23225 checklistsFeb 8-14: 4.1% of 27398 checklistsFeb 15-21: 4.0% of 36606 checklistsFeb 22-28: 3.4% of 27127 checklistsMar 1-7: 3.1% of 29700 checklistsMar 8-14: 3.2% of 31587 checklistsMar 15-21: 3.5% of 32118 checklistsMar 22-31: 3.6% of 47777 checklistsApr 1-7: 4.3% of 38557 checklistsApr 8-14: 4.4% of 42207 checklistsApr 15-21: 4.5% of 42759 checklistsApr 22-30: 4.5% of 64458 checklistsMay 1-7: 4.5% of 60998 checklistsMay 8-14: 3.3% of 72091 checklistsMay 15-21: 2.5% of 59058 checklistsMay 22-31: 1.8% of 64724 checklistsJun 1-7: 1.6% of 35990 checklistsJun 8-14: 1.8% of 32595 checklistsJun 15-21: 1.9% of 30017 checklistsJun 22-30: 1.9% of 33988 checklistsJul 1-7: 2.1% of 28708 checklistsJul 8-14: 1.9% of 25175 checklistsJul 15-21: 2.0% of 24084 checklistsJul 22-31: 2.3% of 33522 checklistsAug 1-7: 2.6% of 25098 checklistsAug 8-14: 3.1% of 24353 checklistsAug 15-21: 3.5% of 25059 checklistsAug 22-31: 3.8% of 37489 checklistsSep 1-7: 4.5% of 28410 checklistsSep 8-14: 5.1% of 27887 checklistsSep 15-21: 5.5% of 26614 checklistsSep 22-30: 5.7% of 32557 checklistsOct 1-7: 5.6% of 25844 checklistsOct 8-14: 5.1% of 27741 checklistsOct 15-21: 4.8% of 24693 checklistsOct 22-31: 4.7% of 32460 checklistsNov 1-7: 4.4% of 23660 checklistsNov 8-14: 4.0% of 21542 checklistsNov 15-21: 4.7% of 19922 checklistsNov 22-30: 4.2% of 25069 checklistsDec 1-7: 4.6% of 18272 checklistsDec 8-14: 5.0% of 18961 checklistsDec 15-21: 4.9% of 24171 checklistsDec 22-31: 4.7% of 30908 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 Michigan 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 Michigan

Best counties

Share of checklists at the peak
  1. Huron CountyBest mid April · 59 checklists that week, 4,733 in all17%
  2. Ogemaw CountyBest mid December · 67 checklists that week, 4,675 in all16%
  3. Osceola CountyBest late January · 96 checklists that week, 5,623 in all13%
  4. Macomb CountyBest early October · 1081 checklists that week, 61,232 in all12%
  5. Clinton CountyBest early October · 266 checklists that week, 10,597 in all11%
  6. Wayne CountyBest mid September · 1411 checklists that week, 68,343 in all11%

Best spots

Share of checklists at the peak
  1. Lakeport State ParkSt. Clair County, best late April · 30 checklists that week, 380 in all68%
  2. Lelsey DrainWashtenaw County, best late October · 24 checklists that week, 175 in all56%
  3. George Suarez Friendship WoodsOakland County, best the second week of April · 165 checklists that week, 4,678 in all39%
  4. Lake Erie Metropark (Cherry Island)Wayne County, best mid October · 28 checklists that week, 696 in all38%
  5. Heritage ParkOakland County, best mid September · 138 checklists that week, 4,532 in all36%

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

Best time of day

In Michigan, the Cooper's Hawk is most often listed on checklists started between 7 and 9 am (4.8% of those checklists).

0%2%4%6%12 am: too few checklists (712) to judge1 am: too few checklists (592) to judge2 am: too few checklists (532) to judge3 am: too few checklists (516) to judge4 am: too few checklists (1592) to judge5 am: too few checklists (6849) to judge6 am: 3.6% of 39298 checklists7 am: 4.8% of 120344 checklists8 am: 4.9% of 180109 checklists9 am: 4.3% of 171966 checklists10 am: 3.9% of 156332 checklists11 am: 3.5% of 134964 checklists12 pm: 3.4% of 120967 checklists1 pm: 3.5% of 113852 checklists2 pm: 3.7% of 110773 checklists3 pm: 3.5% of 105530 checklists4 pm: 3.5% of 100958 checklists5 pm: 3.1% of 80085 checklists6 pm: 2.7% of 62883 checklists7 pm: 2.2% of 44912 checklists8 pm: too few checklists (21062) to judge9 pm: too few checklists (5920) to judge10 pm: too few checklists (1629) to judge11 pm: too few checklists (775) 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
January4.6%4.8%4.8%4.7%
February4.7%4.1%4.0%3.4%
March3.1%3.2%3.5%3.6%
April4.3%4.4%4.5%4.5%
May4.5%3.3%2.5%1.8%
June1.6%1.8%1.9%1.9%
July2.1%1.9%2.0%2.3%
August2.6%3.1%3.5%3.8%
September4.5%5.1%5.5%5.7%
October5.6%5.1%4.8%4.7%
November4.4%4.0%4.7%4.2%
December4.6%5.0%4.9%4.7%

Neighboring states

  • Ohio: arrives early September, 7 weeks later than Michigan
  • Indiana: arrives the second week of September, 8 weeks later than Michigan
  • Illinois: arrives late August, 6 weeks later than Michigan
  • Wisconsin: arrives late August, 6 weeks later than Michigan

Common questions

When do Cooper's Hawks arrive in Michigan?
Cooper's Hawks reach Michigan in the second week of July, are common by the second week of August, peak in late September (5.6% of checklists), and most are gone by the second week of May.
When do Cooper's Hawks leave Michigan?
Most Cooper's Hawks have left Michigan by the second week of May, when reports fall below half their usual rate. Stragglers are still reported until late May.
When is the best time to see a Cooper's Hawk in Michigan?
The Cooper's Hawk is reported most often in late September, on about 5.6% of Michigan checklists.
Where in Michigan are Cooper's Hawks seen most often?
By county, Huron County, Ogemaw County, and Osceola County have the highest peak reporting rates for the Cooper's Hawk (counties with at least 200 checklists).