WhenToBird

Buteo lagopus · Accipitridae

When Do Rough-legged Hawks Arrive in Washington?

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

Rough-legged Hawks are winter birds in Washington: they arrive in late October, peak in late January (1.8% of checklists), and most are gone by mid March.

When to look

First arrivalsOct 22-31late October
Common byOct 22-31late October
PeakJan 22-31late January
Most gone byMar 15-21mid March

Best: late January. First arrivals late October; most are gone by mid March. Peak: on about 1.8% of Washington 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. Octcommon
  11. Novcommon
  12. Decpeak season

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

0%0.5%1%1.5%2%Jan 1-7: 1.3% of 41928 checklistsJan 8-14: 1.5% of 31152 checklistsJan 15-21: 1.9% of 31753 checklistsJan 22-31: 1.8% of 42530 checklistsFeb 1-7: 1.6% of 29739 checklistsFeb 8-14: 1.7% of 32746 checklistsFeb 15-21: 1.4% of 40328 checklistsFeb 22-28: 1.3% of 28432 checklistsMar 1-7: 1.1% of 30758 checklistsMar 8-14: 1.0% of 29368 checklistsMar 15-21: 0.7% of 32580 checklistsMar 22-31: 0.7% of 45614 checklistsApr 1-7: 0.4% of 33997 checklistsApr 8-14: 0.4% of 34729 checklistsApr 15-21: 0.2% of 38474 checklistsApr 22-30: 0.1% of 52185 checklistsMay 1-7: 0.1% of 44236 checklistsMay 8-14: 0.1% of 48708 checklistsMay 15-21: 0.1% of 41742 checklistsMay 22-31: 0% of 57082 checklistsJun 1-7: 0% of 39193 checklistsJun 8-14: 0% of 36042 checklistsJun 15-21: 0% of 34003 checklistsJun 22-30: 0% of 39711 checklistsJul 1-7: 0% of 31949 checklistsJul 8-14: 0% of 29086 checklistsJul 15-21: 0% of 28045 checklistsJul 22-31: 0% of 38275 checklistsAug 1-7: 0% of 28846 checklistsAug 8-14: 0% of 28036 checklistsAug 15-21: 0% of 27614 checklistsAug 22-31: 0% of 40356 checklistsSep 1-7: 0% of 31214 checklistsSep 8-14: 0% of 27795 checklistsSep 15-21: 0% of 29677 checklistsSep 22-30: 0.1% of 35241 checklistsOct 1-7: 0.1% of 28605 checklistsOct 8-14: 0.2% of 28655 checklistsOct 15-21: 0.5% of 24643 checklistsOct 22-31: 0.7% of 34874 checklistsNov 1-7: 1.0% of 25658 checklistsNov 8-14: 1.4% of 25700 checklistsNov 15-21: 1.4% of 24331 checklistsNov 22-30: 1.2% of 32784 checklistsDec 1-7: 1.3% of 24099 checklistsDec 8-14: 1.6% of 23339 checklistsDec 15-21: 1.2% of 27666 checklistsDec 22-31: 1.4% of 42130 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 Washington 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 Washington

Best counties

Share of checklists at the peak
  1. Lincoln CountyBest mid December · 59 checklists that week, 6,135 in all28%
  2. Adams CountyBest mid December · 15 checklists that week, 4,574 in all23%
  3. Cowlitz CountyBest the second week of February · 508 checklists that week, 15,273 in all19%
  4. Douglas CountyBest late January · 386 checklists that week, 9,418 in all17%
  5. Asotin CountyBest early February · 77 checklists that week, 4,316 in all11%
  6. Skagit CountyBest mid January · 2007 checklists that week, 78,154 in all8.3%

Best spots

Share of checklists at the peak
  1. SamishSkagit County, best mid January · 85 checklists that week, 1,512 in all58%

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

Best time of day

In Washington, the Rough-legged Hawk is most often listed on checklists started between 1 and 3 pm (0.9% of those checklists).

0%0.5%1%12 am: too few checklists (796) to judge1 am: too few checklists (776) to judge2 am: too few checklists (709) to judge3 am: too few checklists (901) to judge4 am: too few checklists (3221) to judge5 am: too few checklists (16576) to judge6 am: 0.1% of 56744 checklists7 am: 0.3% of 133294 checklists8 am: 0.4% of 184196 checklists9 am: 0.5% of 186303 checklists10 am: 0.7% of 177063 checklists11 am: 0.8% of 154936 checklists12 pm: 0.8% of 138061 checklists1 pm: 0.9% of 127449 checklists2 pm: 0.9% of 121511 checklists3 pm: 0.8% of 107793 checklists4 pm: 0.5% of 82862 checklists5 pm: 0.2% of 57183 checklists6 pm: 0.1% of 39886 checklists7 pm: too few checklists (26969) to judge8 pm: too few checklists (12427) to judge9 pm: too few checklists (3658) to judge10 pm: too few checklists (1500) to judge11 pm: too few checklists (834) 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
January1.3%1.5%1.9%1.8%
February1.6%1.7%1.4%1.3%
March1.1%1.0%0.7%0.7%
April0.4%0.4%0.2%0.1%
May0.1%0.1%0.1%0%
June0%0%0%0%
July0%0%0%0%
August0%0%0%0%
September0%0%0%0.1%
October0.1%0.2%0.5%0.7%
November1.0%1.4%1.4%1.2%
December1.3%1.6%1.2%1.4%

Neighboring states

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

Common questions

When do Rough-legged Hawks arrive in Washington?
Rough-legged Hawks are winter birds in Washington: they arrive in late October, peak in late January (1.8% of checklists), and most are gone by mid March.
When do Rough-legged Hawks leave Washington?
Most Rough-legged Hawks have left Washington by mid March, when reports fall below half their usual rate.
When is the best time to see a Rough-legged Hawk in Washington?
The Rough-legged Hawk is reported most often in late January, on about 1.8% of Washington checklists.
Where in Washington are Rough-legged Hawks seen most often?
By county, Lincoln County, Adams County, and Cowlitz County have the highest peak reporting rates for the Rough-legged Hawk (counties with at least 200 checklists).