WhenToBird

Circus hudsonius · Accipitridae

When Do Northern Harriers Arrive in Oklahoma?

Northern Harriers are winter birds in Oklahoma: the first arrive in the second week of September, they are common by late September, peak in the second week of December (7.5% of checklists), and most are gone by the second week of April.

When to look

First arrivalsSep 8-14the second week of September
Common bySep 22-30late September
PeakDec 8-14the second week of December
Most gone byApr 8-14the second week of April

Best: the second week of December. First arrivals the second week of September; most are gone by the second week of April. Peak: on about 7.5% of Oklahoma checklists.

  1. Janpeak season
  2. Febcommon
  3. Marcommon
  4. Aprcommon
  5. Mayrare
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augrare
  9. Sepuncommon
  10. Octpeak season
  11. Novpeak season
  12. Decpeak season

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

0%2%4%6%8%Jan 1-7: 7.1% of 6087 checklistsJan 8-14: 6.6% of 4350 checklistsJan 15-21: 6.2% of 4381 checklistsJan 22-31: 6.1% of 6165 checklistsFeb 1-7: 5.0% of 4259 checklistsFeb 8-14: 4.7% of 4589 checklistsFeb 15-21: 4.2% of 7001 checklistsFeb 22-28: 4.6% of 4482 checklistsMar 1-7: 5.2% of 4724 checklistsMar 8-14: 3.8% of 4571 checklistsMar 15-21: 3.9% of 4393 checklistsMar 22-31: 3.9% of 7544 checklistsApr 1-7: 3.2% of 5967 checklistsApr 8-14: 3.1% of 6543 checklistsApr 15-21: 2.3% of 7366 checklistsApr 22-30: 1.0% of 10618 checklistsMay 1-7: 0.4% of 8835 checklistsMay 8-14: 0.2% of 8247 checklistsMay 15-21: 0.1% of 6081 checklistsMay 22-31: 0.1% of 7283 checklistsJun 1-7: 0.1% of 4256 checklistsJun 8-14: 0.1% of 3774 checklistsJun 15-21: 0.1% of 3541 checklistsJun 22-30: 0.1% of 4159 checklistsJul 1-7: 0% of 3209 checklistsJul 8-14: 0.1% of 2916 checklistsJul 15-21: 0.1% of 2861 checklistsJul 22-31: 0.1% of 4146 checklistsAug 1-7: 0.4% of 3043 checklistsAug 8-14: 0.3% of 2839 checklistsAug 15-21: 0.1% of 3014 checklistsAug 22-31: 0.6% of 4759 checklistsSep 1-7: 0.8% of 3861 checklistsSep 8-14: 1.2% of 3748 checklistsSep 15-21: 1.9% of 3569 checklistsSep 22-30: 2.5% of 4830 checklistsOct 1-7: 3.6% of 3809 checklistsOct 8-14: 3.8% of 4142 checklistsOct 15-21: 4.7% of 3705 checklistsOct 22-31: 6.0% of 4738 checklistsNov 1-7: 7.0% of 3823 checklistsNov 8-14: 7.4% of 3849 checklistsNov 15-21: 7.2% of 3722 checklistsNov 22-30: 7.0% of 4795 checklistsDec 1-7: 8.0% of 3324 checklistsDec 8-14: 7.3% of 3574 checklistsDec 15-21: 7.3% of 3884 checklistsDec 22-31: 6.7% of 5774 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 Oklahoma 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 Oklahoma

Best counties

Share of checklists at the peak
  1. Tillman CountyBest early October · 21 checklists that week, 1,199 in all73%
  2. Grant CountyBest late December · 28 checklists that week, 307 in all57%
  3. Beaver CountyBest early December · 15 checklists that week, 838 in all52%
  4. Noble CountyBest early December · 35 checklists that week, 1,320 in all51%
  5. Ellis CountyBest mid February · 11 checklists that week, 357 in all44%
  6. Texas CountyBest early December · 20 checklists that week, 1,542 in all43%

Best spots

Share of checklists at the peak
  1. Greater Flint HillsOsage County, best late January · 23 checklists that week, 221 in all76%
  2. Drummond Flats Wildlife Management AreaGarfield County, best late October · 30 checklists that week, 523 in all71%
  3. Upper Dog PondAlfalfa County, best early November · 30 checklists that week, 783 in all45%
  4. Upper Dog Pond (northwest)Alfalfa County, best early November · 21 checklists that week, 217 in all41%
  5. Waurika LakeJefferson County, best mid January · 20 checklists that week, 139 in all36%

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

Best time of day

In Oklahoma, the Northern Harrier is most often listed on checklists started between 1 and 3 pm (4.3% of those checklists).

0%2%4%6%12 am: too few checklists (91) to judge1 am: too few checklists (65) to judge2 am: too few checklists (73) to judge3 am: too few checklists (73) to judge4 am: too few checklists (100) to judge5 am: too few checklists (647) to judge6 am: 1.9% of 8353 checklists7 am: 2.3% of 24509 checklists8 am: 2.8% of 27848 checklists9 am: 3.5% of 25316 checklists10 am: 3.8% of 21161 checklists11 am: 3.6% of 18730 checklists12 pm: 4.0% of 16097 checklists1 pm: 4.4% of 14028 checklists2 pm: 4.2% of 13599 checklists3 pm: 4.1% of 14228 checklists4 pm: 3.8% of 14597 checklists5 pm: 3.0% of 12125 checklists6 pm: 1.1% of 9337 checklists7 pm: 0.4% of 6944 checklists8 pm: too few checklists (2403) to judge9 pm: too few checklists (459) to judge10 pm: too few checklists (226) to judge11 pm: too few checklists (141) 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
January7.1%6.6%6.2%6.1%
February5.0%4.7%4.2%4.6%
March5.2%3.8%3.9%3.9%
April3.2%3.1%2.3%1.0%
May0.4%0.2%0.1%0.1%
June0.1%0.1%0.1%0.1%
July0%0.1%0.1%0.1%
August0.4%0.3%0.1%0.6%
September0.8%1.2%1.9%2.5%
October3.6%3.8%4.7%6.0%
November7.0%7.4%7.2%7.0%
December8.0%7.3%7.3%6.7%

Neighboring states

  • Kansas: arrives late August, 2 weeks earlier than Oklahoma
  • Arkansas: arrives late September, 2 weeks later than Oklahoma
  • Missouri: arrives late September, 2 weeks later than Oklahoma
  • Nebraska: arrives mid August, 3 weeks earlier than Oklahoma

Common questions

When do Northern Harriers arrive in Oklahoma?
Northern Harriers are winter birds in Oklahoma: the first arrive in the second week of September, they are common by late September, peak in the second week of December (7.5% of checklists), and most are gone by the second week of April.
When do Northern Harriers leave Oklahoma?
Most Northern Harriers have left Oklahoma by the second week of April, when reports fall below half their usual rate. Stragglers are still reported until late April.
When is the best time to see a Northern Harrier in Oklahoma?
The Northern Harrier is reported most often in the second week of December, on about 7.5% of Oklahoma checklists.
Where in Oklahoma are Northern Harriers seen most often?
By county, Tillman County, Grant County, and Beaver County have the highest peak reporting rates for the Northern Harrier (counties with at least 200 checklists).