WhenToBird

Bucephala albeola · Anatidae

When Do Buffleheads Arrive in Idaho?

Adult Bufflehead
Photo: Robert Harris, CC BY 4.0 via iNaturalist

Buffleheads are winter birds in Idaho: the first arrive in early August, they are common by mid October, peak in early November (13% of checklists), and most are gone by early May.

When to look

First arrivalsAug 1-7early August
Common byOct 15-21mid October
PeakNov 1-7early November
Most gone byMay 1-7early May

Best: early November. First arrivals early August; most are gone by early May. Peak: on about 13% of Idaho checklists.

  1. Jancommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Maycommon
  6. Junrare
  7. Julrare
  8. Augrare
  9. Seprare
  10. Octpeak season
  11. Novpeak season
  12. Decpeak season

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

0%5%10%15%Jan 1-7: 11% of 9357 checklistsJan 8-14: 8.7% of 6408 checklistsJan 15-21: 9.0% of 6358 checklistsJan 22-31: 9.8% of 8601 checklistsFeb 1-7: 9.5% of 5611 checklistsFeb 8-14: 9.0% of 6090 checklistsFeb 15-21: 8.6% of 7973 checklistsFeb 22-28: 9.9% of 5866 checklistsMar 1-7: 9.1% of 6144 checklistsMar 8-14: 9.4% of 6456 checklistsMar 15-21: 10% of 6786 checklistsMar 22-31: 12% of 9539 checklistsApr 1-7: 12% of 7202 checklistsApr 8-14: 14% of 7608 checklistsApr 15-21: 14% of 8069 checklistsApr 22-30: 12% of 10973 checklistsMay 1-7: 6.8% of 9481 checklistsMay 8-14: 4.4% of 11318 checklistsMay 15-21: 2.5% of 9141 checklistsMay 22-31: 1.9% of 13984 checklistsJun 1-7: 1.5% of 8897 checklistsJun 8-14: 1.5% of 8504 checklistsJun 15-21: 1.4% of 8078 checklistsJun 22-30: 1.0% of 9665 checklistsJul 1-7: 0.9% of 7144 checklistsJul 8-14: 0.8% of 6557 checklistsJul 15-21: 1.1% of 6430 checklistsJul 22-31: 1.0% of 8696 checklistsAug 1-7: 0.8% of 5896 checklistsAug 8-14: 1.6% of 5643 checklistsAug 15-21: 1.3% of 6151 checklistsAug 22-31: 1.0% of 7863 checklistsSep 1-7: 1.2% of 5769 checklistsSep 8-14: 1.1% of 5646 checklistsSep 15-21: 1.4% of 5460 checklistsSep 22-30: 1.5% of 6363 checklistsOct 1-7: 1.6% of 4980 checklistsOct 8-14: 3.3% of 5096 checklistsOct 15-21: 6.6% of 4878 checklistsOct 22-31: 13% of 6426 checklistsNov 1-7: 13% of 4822 checklistsNov 8-14: 14% of 4999 checklistsNov 15-21: 12% of 4601 checklistsNov 22-30: 12% of 6027 checklistsDec 1-7: 10% of 4180 checklistsDec 8-14: 8.4% of 4775 checklistsDec 15-21: 8.8% of 6522 checklistsDec 22-31: 9.5% 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. Lewis CountyBest mid April · 11 checklists that week, 603 in all73%
  2. Clearwater CountyBest late November · 26 checklists that week, 1,909 in all58%
  3. Gooding CountyBest early December · 34 checklists that week, 3,207 in all55%
  4. Kootenai CountyBest late December · 232 checklists that week, 8,249 in all41%
  5. Benewah CountyBest mid November · 49 checklists that week, 2,541 in all39%
  6. Custer CountyBest the second week of November · 14 checklists that week, 3,853 in all35%

Best spots

Share of checklists at the peak
  1. Wilson Springs Access SiteCanyon County, best late November · 29 checklists that week, 1,000 in all100%
  2. Clearwater RiverNez Perce County, best mid February · 26 checklists that week, 513 in all92%
  3. Clear LakeGooding County, best early January · 41 checklists that week, 174 in all91%
  4. Mountain Home ReservoirElmore County, best mid April · 24 checklists that week, 417 in all91%

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

Best time of day

In Idaho, the Bufflehead is most often listed on checklists started between 2 and 4 pm (8.5% of those checklists).

0%5%10%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: 2.3% of 9122 checklists7 am: 4.2% of 22204 checklists8 am: 5.1% of 38672 checklists9 am: 6.5% of 38930 checklists10 am: 6.9% of 37338 checklists11 am: 7.8% of 33508 checklists12 pm: 7.7% of 28544 checklists1 pm: 8.4% of 25774 checklists2 pm: 8.6% of 24296 checklists3 pm: 8.4% of 21784 checklists4 pm: 6.7% of 19051 checklists5 pm: 5.0% of 14150 checklists6 pm: 3.9% of 10014 checklists7 pm: 2.4% 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
January11%8.7%9.0%9.8%
February9.5%9.0%8.6%9.9%
March9.1%9.4%10%12%
April12%14%14%12%
May6.8%4.4%2.5%1.9%
June1.5%1.5%1.4%1.0%
July0.9%0.8%1.1%1.0%
August0.8%1.6%1.3%1.0%
September1.2%1.1%1.4%1.5%
October1.6%3.3%6.6%13%
November13%14%12%12%
December10%8.4%8.8%9.5%

Neighboring states

  • Montana: arrives mid August, 2 weeks later than Idaho
  • Utah: arrives mid October, 10 weeks later than Idaho
  • Oregon: arrives the second week of October, 9 weeks later than Idaho
  • Washington: arrives mid October, 10 weeks later than Idaho

Common questions

When do Buffleheads arrive in Idaho?
Buffleheads are winter birds in Idaho: the first arrive in early August, they are common by mid October, peak in early November (13% of checklists), and most are gone by early May.
When do Buffleheads leave Idaho?
Most Buffleheads have left Idaho by early May, when reports fall below half their usual rate. Stragglers are still reported until late June.
When is the best time to see a Bufflehead in Idaho?
The Bufflehead is reported most often in early November, on about 13% of Idaho checklists.
Where in Idaho are Buffleheads seen most often?
By county, Lewis County, Clearwater County, and Gooding County have the highest peak reporting rates for the Bufflehead (counties with at least 200 checklists).