WhenToBird

Circus hudsonius · Accipitridae

When Do Northern Harriers Arrive in Utah?

Northern Harriers are winter birds in Utah: the first arrive in the second week of August, they are common by the second week of September, peak in late January (13% of checklists), and most are gone by late April.

When to look

First arrivalsAug 8-14the second week of August
Common bySep 8-14the second week of September
PeakJan 22-31late January
Most gone byApr 22-30late April

Best: late January. First arrivals the second week of August; most are gone by late April. Peak: on about 13% of Utah checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marpeak season
  4. Aprcommon
  5. Maycommon
  6. Jununcommon
  7. Juluncommon
  8. Auguncommon
  9. Sepcommon
  10. Octcommon
  11. Novpeak season
  12. Decpeak season

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

0%5%10%15%Jan 1-7: 12% of 10857 checklistsJan 8-14: 12% of 8333 checklistsJan 15-21: 11% of 8360 checklistsJan 22-31: 14% of 10516 checklistsFeb 1-7: 12% of 7416 checklistsFeb 8-14: 11% of 8082 checklistsFeb 15-21: 9.6% of 9643 checklistsFeb 22-28: 12% of 7960 checklistsMar 1-7: 10% of 7998 checklistsMar 8-14: 10% of 8581 checklistsMar 15-21: 8.9% of 8637 checklistsMar 22-31: 9.3% of 13006 checklistsApr 1-7: 8.5% of 10562 checklistsApr 8-14: 7.6% of 11694 checklistsApr 15-21: 7.4% of 11382 checklistsApr 22-30: 6.1% of 16626 checklistsMay 1-7: 5.1% of 13523 checklistsMay 8-14: 4.1% of 14714 checklistsMay 15-21: 4.6% of 13711 checklistsMay 22-31: 2.9% of 16546 checklistsJun 1-7: 2.3% of 10284 checklistsJun 8-14: 2.1% of 9530 checklistsJun 15-21: 1.9% of 8854 checklistsJun 22-30: 2.1% of 10566 checklistsJul 1-7: 2.0% of 7987 checklistsJul 8-14: 2.0% of 7471 checklistsJul 15-21: 2.0% of 7240 checklistsJul 22-31: 2.3% of 9329 checklistsAug 1-7: 2.3% of 6521 checklistsAug 8-14: 3.2% of 6423 checklistsAug 15-21: 3.0% of 6208 checklistsAug 22-31: 4.1% of 9089 checklistsSep 1-7: 5.5% of 7081 checklistsSep 8-14: 5.6% of 7306 checklistsSep 15-21: 6.2% of 7208 checklistsSep 22-30: 7.4% of 8876 checklistsOct 1-7: 6.7% of 7265 checklistsOct 8-14: 7.5% of 7226 checklistsOct 15-21: 7.4% of 7007 checklistsOct 22-31: 8.1% of 8443 checklistsNov 1-7: 8.9% of 6711 checklistsNov 8-14: 9.4% of 6290 checklistsNov 15-21: 9.6% of 6169 checklistsNov 22-30: 11% of 8228 checklistsDec 1-7: 9.7% of 6011 checklistsDec 8-14: 10% of 6044 checklistsDec 15-21: 9.7% of 6721 checklistsDec 22-31: 11% of 9982 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 Utah 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 Utah

Best counties

Share of checklists at the peak
  1. Box Elder CountyBest early February · 147 checklists that week, 9,867 in all39%
  2. Davis CountyBest late January · 1014 checklists that week, 39,952 in all39%
  3. Juab CountyBest mid December · 20 checklists that week, 2,572 in all28%
  4. Millard CountyBest early March · 91 checklists that week, 2,206 in all23%
  5. Tooele CountyBest early April · 113 checklists that week, 4,788 in all22%
  6. Kane CountyBest early January · 76 checklists that week, 6,105 in all21%

Best spots

Share of checklists at the peak
  1. Ogden Bay State Wildlife Area (South Fork Weber River)Weber County, best late January · 22 checklists that week, 302 in all98%
  2. Harold Crane State Wildlife AreaWeber County, best late December · 26 checklists that week, 173 in all94%
  3. Utah State Department of Wildlife Resources 165Davis County, best late January · 158 checklists that week, 4,840 in all93%
  4. Ogden Bay State Wildlife AreaWeber County, best late January · 26 checklists that week, 498 in all91%

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

Best time of day

In Utah, the Northern Harrier is most often listed on checklists started between 2 and 4 pm (8.6% of those checklists).

0%5%10%12 am: too few checklists (242) to judge1 am: too few checklists (178) to judge2 am: too few checklists (169) to judge3 am: too few checklists (162) to judge4 am: too few checklists (284) to judge5 am: too few checklists (1984) to judge6 am: 5.7% of 11714 checklists7 am: 6.2% of 33209 checklists8 am: 6.0% of 46944 checklists9 am: 7.0% of 46290 checklists10 am: 7.5% of 43144 checklists11 am: 7.6% of 36893 checklists12 pm: 8.0% of 32758 checklists1 pm: 8.4% of 30142 checklists2 pm: 8.8% of 29414 checklists3 pm: 8.5% of 29491 checklists4 pm: 7.6% of 29154 checklists5 pm: 6.2% of 22256 checklists6 pm: 4.7% of 17383 checklists7 pm: 3.0% of 13099 checklists8 pm: too few checklists (6647) to judge9 pm: too few checklists (1753) to judge10 pm: too few checklists (599) to judge11 pm: too few checklists (307) 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
January12%12%11%14%
February12%11%9.6%12%
March10%10%8.9%9.3%
April8.5%7.6%7.4%6.1%
May5.1%4.1%4.6%2.9%
June2.3%2.1%1.9%2.1%
July2.0%2.0%2.0%2.3%
August2.3%3.2%3.0%4.1%
September5.5%5.6%6.2%7.4%
October6.7%7.5%7.4%8.1%
November8.9%9.4%9.6%11%
December9.7%10%9.7%11%

Neighboring states

  • Wyoming: arrives early April, 17 weeks earlier than Utah
  • Nevada: arrives the second week of October, 8 weeks later than Utah
  • Colorado: arrives the second week of August, in the same week than Utah
  • Idaho: arrives early March, 21 weeks earlier than Utah

Common questions

When do Northern Harriers arrive in Utah?
Northern Harriers are winter birds in Utah: the first arrive in the second week of August, they are common by the second week of September, peak in late January (13% of checklists), and most are gone by late April.
When do Northern Harriers leave Utah?
Most Northern Harriers have left Utah by late April, when reports fall below half their usual rate. Stragglers are still reported until late May.
When is the best time to see a Northern Harrier in Utah?
The Northern Harrier is reported most often in late January, on about 13% of Utah checklists.
Where in Utah are Northern Harriers seen most often?
By county, Box Elder County, Davis County, and Juab County have the highest peak reporting rates for the Northern Harrier (counties with at least 200 checklists).