WhenToBird

Buteo lagopus · Accipitridae

When Do Rough-legged Hawks Arrive in Wisconsin?

Adult Rough-legged Hawk
Photo: Rev. Lee A. Payne, Jr., CC BY 4.0 via iNaturalist

Rough-legged Hawks are winter birds in Wisconsin: they arrive in early November, peak in the second week of January (3.4% of checklists), and most are gone by early April.

When to look

First arrivalsNov 1-7early November
Common byNov 1-7early November
PeakJan 8-14the second week of January
Most gone byApr 1-7early April

Best: the second week of January. First arrivals early November; most are gone by early April. Peak: on about 3.4% of Wisconsin checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marcommon
  4. Apruncommon
  5. Mayrare
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepnot usually seen
  10. Octuncommon
  11. Novcommon
  12. Decpeak season

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

0%1%2%3%4%Jan 1-7: 3.5% of 27925 checklistsJan 8-14: 3.1% of 18337 checklistsJan 15-21: 3.4% of 17370 checklistsJan 22-31: 3.4% of 23777 checklistsFeb 1-7: 3.3% of 16656 checklistsFeb 8-14: 2.8% of 18286 checklistsFeb 15-21: 2.2% of 24739 checklistsFeb 22-28: 2.5% of 20113 checklistsMar 1-7: 2.2% of 24024 checklistsMar 8-14: 1.9% of 26722 checklistsMar 15-21: 1.8% of 27238 checklistsMar 22-31: 1.5% of 40171 checklistsApr 1-7: 1.3% of 34961 checklistsApr 8-14: 0.8% of 39128 checklistsApr 15-21: 0.6% of 38887 checklistsApr 22-30: 0.4% of 57231 checklistsMay 1-7: 0.2% of 55115 checklistsMay 8-14: 0.1% of 63098 checklistsMay 15-21: 0.1% of 49821 checklistsMay 22-31: 0.1% of 56796 checklistsJun 1-7: 0.1% of 33621 checklistsJun 8-14: 0% of 31282 checklistsJun 15-21: 0% of 30186 checklistsJun 22-30: 0% of 35128 checklistsJul 1-7: 0% of 27088 checklistsJul 8-14: 0% of 23293 checklistsJul 15-21: 0% of 20933 checklistsJul 22-31: 0% of 27595 checklistsAug 1-7: 0% of 19147 checklistsAug 8-14: 0% of 18286 checklistsAug 15-21: 0% of 19195 checklistsAug 22-31: 0% of 28229 checklistsSep 1-7: 0.1% of 22408 checklistsSep 8-14: 0% of 20857 checklistsSep 15-21: 0.1% of 20707 checklistsSep 22-30: 0% of 26469 checklistsOct 1-7: 0.1% of 21069 checklistsOct 8-14: 0.1% of 21011 checklistsOct 15-21: 0.2% of 20006 checklistsOct 22-31: 0.8% of 26362 checklistsNov 1-7: 1.5% of 18928 checklistsNov 8-14: 1.5% of 17052 checklistsNov 15-21: 1.9% of 16291 checklistsNov 22-30: 1.7% of 20564 checklistsDec 1-7: 1.6% of 15354 checklistsDec 8-14: 2.0% of 16294 checklistsDec 15-21: 2.4% of 21430 checklistsDec 22-31: 2.7% of 26314 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 Wisconsin 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 Wisconsin

Best counties

Share of checklists at the peak
  1. Adams CountyBest early February · 44 checklists that week, 5,946 in all33%
  2. Burnett CountyBest early December · 28 checklists that week, 11,034 in all20%
  3. Monroe CountyBest mid January · 16 checklists that week, 3,836 in all18%
  4. Clark CountyBest late March · 25 checklists that week, 2,369 in all18%
  5. Calumet CountyBest the second week of January · 146 checklists that week, 12,359 in all14%
  6. Taylor CountyBest the second week of December · 31 checklists that week, 4,326 in all12%

Best spots

Share of checklists at the peak
  1. Rat River Wildlife AreaWinnebago County, best late January · 21 checklists that week, 528 in all70%
  2. Killsnake Wildlife AreaCalumet County, best the second week of March · 23 checklists that week, 572 in all56%
  3. Lake Mills Wildlife AreaJefferson County, best mid January · 21 checklists that week, 1,592 in all38%

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

Best time of day

In Wisconsin, the Rough-legged Hawk is most often listed on checklists started between 2 and 4 pm (1.5% of those checklists).

0%0.5%1%1.5%2%12 am: too few checklists (993) to judge1 am: too few checklists (844) to judge2 am: too few checklists (839) to judge3 am: too few checklists (1488) to judge4 am: too few checklists (5344) to judge5 am: 0.2% of 27016 checklists6 am: 0.3% of 83973 checklists7 am: 0.5% of 160717 checklists8 am: 0.6% of 160531 checklists9 am: 0.9% of 136968 checklists10 am: 1.1% of 119110 checklists11 am: 1.3% of 99116 checklists12 pm: 1.4% of 85078 checklists1 pm: 1.4% of 80688 checklists2 pm: 1.4% of 79140 checklists3 pm: 1.5% of 78599 checklists4 pm: 1.1% of 69767 checklists5 pm: 0.4% of 53229 checklists6 pm: 0.2% of 38769 checklists7 pm: too few checklists (24396) to judge8 pm: too few checklists (10155) to judge9 pm: too few checklists (4990) to judge10 pm: too few checklists (2463) to judge11 pm: too few checklists (1281) 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
January3.5%3.1%3.4%3.4%
February3.3%2.8%2.2%2.5%
March2.2%1.9%1.8%1.5%
April1.3%0.8%0.6%0.4%
May0.2%0.1%0.1%0.1%
June0.1%0%0%0%
July0%0%0%0%
August0%0%0%0%
September0.1%0%0.1%0%
October0.1%0.1%0.2%0.8%
November1.5%1.5%1.9%1.7%
December1.6%2.0%2.4%2.7%

Neighboring states

  • Illinois: arrives early November, in the same week than Wisconsin
  • Iowa: arrives the second week of November, 1 week later than Wisconsin
  • Michigan: arrives late October, 1 week earlier than Wisconsin
  • Minnesota: arrives mid October, 2 weeks earlier than Wisconsin

Common questions

When do Rough-legged Hawks arrive in Wisconsin?
Rough-legged Hawks are winter birds in Wisconsin: they arrive in early November, peak in the second week of January (3.4% of checklists), and most are gone by early April.
When do Rough-legged Hawks leave Wisconsin?
Most Rough-legged Hawks have left Wisconsin by early April, when reports fall below half their usual rate.
When is the best time to see a Rough-legged Hawk in Wisconsin?
The Rough-legged Hawk is reported most often in the second week of January, on about 3.4% of Wisconsin checklists.
Where in Wisconsin are Rough-legged Hawks seen most often?
By county, Adams County, Burnett County, and Monroe County have the highest peak reporting rates for the Rough-legged Hawk (counties with at least 200 checklists).