WhenToBird

Falco peregrinus · Falconidae

When Do Peregrine Falcons Arrive in Idaho?

Adult Peregrine Falcon
Photo: Andrea Poggi, CC BY 4.0 via iNaturalist

Peregrine Falcons reach Idaho in late January, are common by the second week of February, peak in late August (1.2% of checklists), and most are gone by late December.

When to look

First arrivalsJan 22-31late January
Common byFeb 8-14the second week of February
PeakAug 22-31late August
Most gone byDec 22-31late December

Best: late August. First arrivals late January; most are gone by late December. Peak: on about 1.2% of Idaho checklists.

  1. Januncommon
  2. Febuncommon
  3. Maruncommon
  4. Apruncommon
  5. Mayuncommon
  6. Jununcommon
  7. Julcommon
  8. Augpeak season
  9. Seppeak season
  10. Octcommon
  11. Novuncommon
  12. Decuncommon

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

0%0.5%1%1.5%Jan 1-7: 0.2% of 9357 checklistsJan 8-14: 0.2% of 6408 checklistsJan 15-21: 0.3% of 6358 checklistsJan 22-31: 0.2% of 8601 checklistsFeb 1-7: 0.3% of 5611 checklistsFeb 8-14: 0.3% of 6090 checklistsFeb 15-21: 0.3% of 7973 checklistsFeb 22-28: 0.2% of 5866 checklistsMar 1-7: 0.3% of 6144 checklistsMar 8-14: 0.3% of 6456 checklistsMar 15-21: 0.3% of 6786 checklistsMar 22-31: 0.4% of 9539 checklistsApr 1-7: 0.3% of 7202 checklistsApr 8-14: 0.5% of 7608 checklistsApr 15-21: 0.4% of 8069 checklistsApr 22-30: 0.5% of 10973 checklistsMay 1-7: 0.3% of 9481 checklistsMay 8-14: 0.3% of 11318 checklistsMay 15-21: 0.4% of 9141 checklistsMay 22-31: 0.4% of 13984 checklistsJun 1-7: 0.3% of 8897 checklistsJun 8-14: 0.3% of 8504 checklistsJun 15-21: 0.3% of 8078 checklistsJun 22-30: 0.3% of 9665 checklistsJul 1-7: 0.5% of 7144 checklistsJul 8-14: 0.4% of 6557 checklistsJul 15-21: 0.5% of 6430 checklistsJul 22-31: 0.5% of 8696 checklistsAug 1-7: 0.8% of 5896 checklistsAug 8-14: 1.1% of 5643 checklistsAug 15-21: 1.3% of 6151 checklistsAug 22-31: 1.1% of 7863 checklistsSep 1-7: 1.2% of 5769 checklistsSep 8-14: 0.9% of 5646 checklistsSep 15-21: 1.1% of 5460 checklistsSep 22-30: 0.7% of 6363 checklistsOct 1-7: 0.6% of 4980 checklistsOct 8-14: 0.4% of 5096 checklistsOct 15-21: 0.4% of 4878 checklistsOct 22-31: 0.3% of 6426 checklistsNov 1-7: 0.4% of 4822 checklistsNov 8-14: 0.4% of 4999 checklistsNov 15-21: 0.3% of 4601 checklistsNov 22-30: 0.4% of 6027 checklistsDec 1-7: 0.3% of 4180 checklistsDec 8-14: 0.4% of 4775 checklistsDec 15-21: 0.5% of 6522 checklistsDec 22-31: 0.4% 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. Clark CountyBest late April · 10 checklists that week, 578 in all7.4%
  2. Power CountyBest the second week of August · 52 checklists that week, 2,278 in all6.7%
  3. Jefferson CountyBest the second week of September · 121 checklists that week, 5,319 in all6.4%
  4. Gooding CountyBest the second week of June · 29 checklists that week, 3,207 in all4.6%
  5. Bingham CountyBest mid August · 46 checklists that week, 1,427 in all4.4%
  6. Nez Perce CountyBest mid September · 185 checklists that week, 10,708 in all4.3%

Best spots

Share of checklists at the peak
  1. Mann LakeNez Perce County, best mid September · 36 checklists that week, 1,366 in all15%
  2. Camas National Wildlife RefugeJefferson County, best the second week of September · 31 checklists that week, 540 in all13%
  3. Boise River Wildlife Management AreaAda County, best the second week of September · 92 checklists that week, 733 in all11%
  4. Camas National Wildlife Refuge (Willow Pond (historical))Jefferson County, best mid August · 22 checklists that week, 354 in all10%
  5. Clearwater RiverNez Perce County, best the second week of February · 20 checklists that week, 513 in all9.2%

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

Best time of day

In Idaho, the Peregrine Falcon is most often listed on checklists started between 6 and 8 am (0.7% of those checklists).

0%0.5%1%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: 0.7% of 9122 checklists7 am: 0.7% of 22204 checklists8 am: 0.6% of 38672 checklists9 am: 0.4% of 38930 checklists10 am: 0.5% of 37338 checklists11 am: 0.4% of 33508 checklists12 pm: 0.4% of 28544 checklists1 pm: 0.4% of 25774 checklists2 pm: 0.4% of 24296 checklists3 pm: 0.5% of 21784 checklists4 pm: 0.3% of 19051 checklists5 pm: 0.4% of 14150 checklists6 pm: 0.4% of 10014 checklists7 pm: 0.4% 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
January0.2%0.2%0.3%0.2%
February0.3%0.3%0.3%0.2%
March0.3%0.3%0.3%0.4%
April0.3%0.5%0.4%0.5%
May0.3%0.3%0.4%0.4%
June0.3%0.3%0.3%0.3%
July0.5%0.4%0.5%0.5%
August0.8%1.1%1.3%1.1%
September1.2%0.9%1.1%0.7%
October0.6%0.4%0.4%0.3%
November0.4%0.4%0.3%0.4%
December0.3%0.4%0.5%0.4%

Neighboring states

  • Montana: arrives late March, 8 weeks later than Idaho
  • Utah: arrives late February, 4 weeks later than Idaho
  • Oregon: arrives mid June, 19 weeks later than Idaho
  • Washington: arrives the second week of July, 22 weeks later than Idaho

Common questions

When do Peregrine Falcons arrive in Idaho?
Peregrine Falcons reach Idaho in late January, are common by the second week of February, peak in late August (1.2% of checklists), and most are gone by late December.
When do Peregrine Falcons leave Idaho?
Most Peregrine Falcons have left Idaho by late December, when reports fall below half their usual rate. Stragglers are still reported until early January.
When is the best time to see a Peregrine Falcon in Idaho?
The Peregrine Falcon is reported most often in late August, on about 1.2% of Idaho checklists.
Where in Idaho are Peregrine Falcons seen most often?
By county, Clark County, Power County, and Jefferson County have the highest peak reporting rates for the Peregrine Falcon (counties with at least 200 checklists).