WhenToBird

Buteo lagopus · Accipitridae

When Do Rough-legged Hawks Arrive in Idaho?

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

Rough-legged Hawks are winter birds in Idaho: they arrive in late October, peak in early January (3.9% of checklists), and most are gone by early April.

When to look

First arrivalsOct 22-31late October
Common byOct 22-31late October
PeakJan 1-7early January
Most gone byApr 1-7early April

Best: early January. First arrivals late October; most are gone by early April. Peak: on about 3.9% of Idaho checklists.

  1. Janpeak season
  2. Febcommon
  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%2%4%6%Jan 1-7: 4.2% of 9357 checklistsJan 8-14: 3.5% of 6408 checklistsJan 15-21: 3.7% of 6358 checklistsJan 22-31: 2.8% of 8601 checklistsFeb 1-7: 3.1% of 5611 checklistsFeb 8-14: 2.7% of 6090 checklistsFeb 15-21: 2.6% of 7973 checklistsFeb 22-28: 2.2% of 5866 checklistsMar 1-7: 2.4% of 6144 checklistsMar 8-14: 3.1% of 6456 checklistsMar 15-21: 2.6% of 6786 checklistsMar 22-31: 1.8% of 9539 checklistsApr 1-7: 1.2% of 7202 checklistsApr 8-14: 1.1% of 7608 checklistsApr 15-21: 0.6% of 8069 checklistsApr 22-30: 0.2% of 10973 checklistsMay 1-7: 0.1% of 9481 checklistsMay 8-14: 0.1% of 11318 checklistsMay 15-21: 0% of 9141 checklistsMay 22-31: 0% of 13984 checklistsJun 1-7: 0% of 8897 checklistsJun 8-14: 0% of 8504 checklistsJun 15-21: 0% of 8078 checklistsJun 22-30: 0% of 9665 checklistsJul 1-7: 0% of 7144 checklistsJul 8-14: 0% of 6557 checklistsJul 15-21: 0% of 6430 checklistsJul 22-31: 0% of 8696 checklistsAug 1-7: 0% of 5896 checklistsAug 8-14: 0% of 5643 checklistsAug 15-21: 0% of 6151 checklistsAug 22-31: 0% of 7863 checklistsSep 1-7: 0% of 5769 checklistsSep 8-14: 0% of 5646 checklistsSep 15-21: 0% of 5460 checklistsSep 22-30: 0% of 6363 checklistsOct 1-7: 0.1% of 4980 checklistsOct 8-14: 0.3% of 5096 checklistsOct 15-21: 1.0% of 4878 checklistsOct 22-31: 1.4% of 6426 checklistsNov 1-7: 1.8% of 4822 checklistsNov 8-14: 3.1% of 4999 checklistsNov 15-21: 2.8% of 4601 checklistsNov 22-30: 2.5% of 6027 checklistsDec 1-7: 3.3% of 4180 checklistsDec 8-14: 2.2% of 4775 checklistsDec 15-21: 2.8% of 6522 checklistsDec 22-31: 3.7% 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.

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Where in Idaho

Best counties

Share of checklists at the peak
  1. Butte CountyBest late December · 24 checklists that week, 1,276 in all55%
  2. Jefferson CountyBest the second week of January · 44 checklists that week, 5,319 in all47%
  3. Teton CountyBest the second week of December · 86 checklists that week, 6,406 in all30%
  4. Oneida CountyBest late December · 15 checklists that week, 1,750 in all30%
  5. Camas CountyBest late November · 13 checklists that week, 2,112 in all29%
  6. Lemhi CountyBest early February · 83 checklists that week, 6,242 in all25%

Best spots

Share of checklists at the peak
  1. Morley Nelson Snake River Birds of Prey National Conservation AreaElmore County, best the second week of January · 29 checklists that week, 1,056 in all17%
  2. Indian Creek Reservoir Access SiteAda County, best the second week of March · 26 checklists that week, 1,086 in all13%
  3. Morley Nelson Snake River Birds of Prey National Conservation Area (northwest)Ada County, best mid March · 31 checklists that week, 571 in all12%

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

Best time of day

In Idaho, the Rough-legged Hawk is most often listed on checklists started between 1 and 3 pm (1.9% of those checklists).

0%0.5%1%1.5%2%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: 0.1% of 9122 checklists7 am: 0.4% of 22204 checklists8 am: 0.7% of 38672 checklists9 am: 1.1% of 38930 checklists10 am: 1.5% of 37338 checklists11 am: 1.7% of 33508 checklists12 pm: 1.8% of 28544 checklists1 pm: 1.9% of 25774 checklists2 pm: 1.8% of 24296 checklists3 pm: 1.6% of 21784 checklists4 pm: 1.1% of 19051 checklists5 pm: 0.7% of 14150 checklists6 pm: 0.3% of 10014 checklists7 pm: 0.3% 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
January4.2%3.5%3.7%2.8%
February3.1%2.7%2.6%2.2%
March2.4%3.1%2.6%1.8%
April1.2%1.1%0.6%0.2%
May0.1%0.1%0%0%
June0%0%0%0%
July0%0%0%0%
August0%0%0%0%
September0%0%0%0%
October0.1%0.3%1.0%1.4%
November1.8%3.1%2.8%2.5%
December3.3%2.2%2.8%3.7%

Neighboring states

  • Montana: arrives early October, 3 weeks earlier than Idaho
  • Utah: arrives the second week of November, 2 weeks later than Idaho
  • Oregon: arrives early November, 1 week later than Idaho
  • Washington: arrives late October, in the same week than Idaho

Common questions

When do Rough-legged Hawks arrive in Idaho?
Rough-legged Hawks are winter birds in Idaho: they arrive in late October, peak in early January (3.9% of checklists), and most are gone by early April.
When do Rough-legged Hawks leave Idaho?
Most Rough-legged Hawks have left Idaho by early April, when reports fall below half their usual rate.
When is the best time to see a Rough-legged Hawk in Idaho?
The Rough-legged Hawk is reported most often in early January, on about 3.9% of Idaho checklists.
Where in Idaho are Rough-legged Hawks seen most often?
By county, Butte County, Jefferson County, and Teton County have the highest peak reporting rates for the Rough-legged Hawk (counties with at least 200 checklists).