WhenToBird

Buteo lagopus · Accipitridae

When Do Rough-legged Hawks Arrive in Wyoming?

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

Rough-legged Hawks are winter birds in Wyoming: the first arrive in mid October, they are common by the second week of November, peak in the second week of January (9.0% of checklists), and most are gone by mid March.

When to look

First arrivalsOct 15-21mid October
Common byNov 8-14the second week of November
PeakJan 8-14the second week of January
Most gone byMar 15-21mid March

Best: the second week of January. First arrivals mid October; most are gone by mid March. Peak: on about 9.0% of Wyoming checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marcommon
  4. Apruncommon
  5. Maynot usually seen
  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%5%10%Jan 1-7: 8.3% of 2543 checklistsJan 8-14: 9.0% of 2114 checklistsJan 15-21: 9.9% of 1984 checklistsJan 22-31: 7.6% of 2605 checklistsFeb 1-7: 7.2% of 1940 checklistsFeb 8-14: 6.4% of 1954 checklistsFeb 15-21: 7.1% of 2575 checklistsFeb 22-28: 5.7% of 1932 checklistsMar 1-7: 6.0% of 2486 checklistsMar 8-14: 5.2% of 2535 checklistsMar 15-21: 3.7% of 2726 checklistsMar 22-31: 2.6% of 4349 checklistsApr 1-7: 1.1% of 3300 checklistsApr 8-14: 0.5% of 3500 checklistsApr 15-21: 0.5% of 3701 checklistsApr 22-30: 0.2% of 5887 checklistsMay 1-7: 0% of 5341 checklistsMay 8-14: 0% of 6910 checklistsMay 15-21: 0% of 6884 checklistsMay 22-31: 0.1% of 10652 checklistsJun 1-7: 0% of 6807 checklistsJun 8-14: 0% of 6714 checklistsJun 15-21: 0% of 6708 checklistsJun 22-30: 0% of 8160 checklistsJul 1-7: 0% of 5755 checklistsJul 8-14: 0% of 5379 checklistsJul 15-21: 0% of 5299 checklistsJul 22-31: 0% of 6830 checklistsAug 1-7: 0% of 4581 checklistsAug 8-14: 0% of 4625 checklistsAug 15-21: 0% of 4466 checklistsAug 22-31: 0% of 6562 checklistsSep 1-7: 0.1% of 4543 checklistsSep 8-14: 0% of 4652 checklistsSep 15-21: 0.1% of 4186 checklistsSep 22-30: 0.1% of 5301 checklistsOct 1-7: 0.3% of 3248 checklistsOct 8-14: 0.6% of 3010 checklistsOct 15-21: 0.9% of 2624 checklistsOct 22-31: 2.2% of 3170 checklistsNov 1-7: 2.6% of 2110 checklistsNov 8-14: 4.0% of 2153 checklistsNov 15-21: 6.0% of 1971 checklistsNov 22-30: 5.8% of 2136 checklistsDec 1-7: 5.8% of 1646 checklistsDec 8-14: 6.0% of 1609 checklistsDec 15-21: 6.6% of 1954 checklistsDec 22-31: 7.3% of 2392 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 Wyoming 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 Wyoming

Best counties

Share of checklists at the peak
  1. Goshen CountyBest late January · 32 checklists that week, 1,920 in all28%
  2. Big Horn CountyBest early December · 17 checklists that week, 2,023 in all20%
  3. Sheridan CountyBest the second week of January · 73 checklists that week, 6,459 in all20%
  4. Johnson CountyBest late January · 104 checklists that week, 5,977 in all19%
  5. Uinta CountyBest late November · 14 checklists that week, 1,881 in all17%
  6. Laramie CountyBest late January · 290 checklists that week, 15,593 in all14%

Best spots

Share of checklists at the peak
  1. Optomist ParkAlbany County, best mid December · 35 checklists that week, 2,101 in all20%
  2. Wyoming Hereford Ranch Reservoir Number OneLaramie County, best mid February · 22 checklists that week, 1,242 in all13%
  3. Gelatt LakeAlbany County, best late March · 21 checklists that week, 180 in all13%
  4. Meeboer LakeAlbany County, best late March · 33 checklists that week, 300 in all13%

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

Best time of day

In Wyoming, the Rough-legged Hawk is most often listed on checklists started between 1 and 3 pm (2.3% of those checklists).

0%1%2%3%12 am: too few checklists (59) to judge1 am: too few checklists (76) to judge2 am: too few checklists (86) to judge3 am: too few checklists (79) to judge4 am: too few checklists (326) to judge5 am: too few checklists (2271) to judge6 am: 0.1% of 8808 checklists7 am: 0.7% of 18458 checklists8 am: 1.4% of 22143 checklists9 am: 1.7% of 21499 checklists10 am: 2.2% of 19425 checklists11 am: 2.2% of 16017 checklists12 pm: 2.2% of 13868 checklists1 pm: 2.3% of 12984 checklists2 pm: 2.3% of 12605 checklists3 pm: 1.9% of 11821 checklists4 pm: 1.3% of 10571 checklists5 pm: 0.5% of 8746 checklists6 pm: 0.2% of 6707 checklists7 pm: 0.1% of 4890 checklists8 pm: too few checklists (2323) to judge9 pm: too few checklists (554) to judge10 pm: too few checklists (134) to judge11 pm: too few checklists (59) 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
January8.3%9.0%9.9%7.6%
February7.2%6.4%7.1%5.7%
March6.0%5.2%3.7%2.6%
April1.1%0.5%0.5%0.2%
May0%0%0%0.1%
June0%0%0%0%
July0%0%0%0%
August0%0%0%0%
September0.1%0%0.1%0.1%
October0.3%0.6%0.9%2.2%
November2.6%4.0%6.0%5.8%
December5.8%6.0%6.6%7.3%

Neighboring states

  • Colorado: arrives the second week of November, 3 weeks later than Wyoming
  • Utah: arrives the second week of November, 3 weeks later than Wyoming
  • Montana: arrives early October, 2 weeks earlier than Wyoming
  • Idaho: arrives late October, 1 week later than Wyoming

Common questions

When do Rough-legged Hawks arrive in Wyoming?
Rough-legged Hawks are winter birds in Wyoming: the first arrive in mid October, they are common by the second week of November, peak in the second week of January (9.0% of checklists), and most are gone by mid March.
When do Rough-legged Hawks leave Wyoming?
Most Rough-legged Hawks have left Wyoming by mid March, when reports fall below half their usual rate. Stragglers are still reported until early April.
When is the best time to see a Rough-legged Hawk in Wyoming?
The Rough-legged Hawk is reported most often in the second week of January, on about 9.0% of Wyoming checklists.
Where in Wyoming are Rough-legged Hawks seen most often?
By county, Goshen County, Big Horn County, and Sheridan County have the highest peak reporting rates for the Rough-legged Hawk (counties with at least 200 checklists).