WhenToBird

Falco mexicanus · Falconidae

When Do Prairie Falcons Arrive in Arizona?

Adult Prairie Falcon
Photo: CK2AZ, CC BY 4.0 via iNaturalist

Prairie Falcons are winter birds in Arizona: they arrive in the second week of September, peak in the second week of December (1.2% of checklists), and most are gone by early March.

When to look

First arrivalsSep 8-14the second week of September
Common bySep 8-14the second week of September
PeakDec 8-14the second week of December
Most gone byMar 1-7early March

Best: the second week of December. First arrivals the second week of September; most are gone by early March. Peak: on about 1.2% of Arizona checklists.

  1. Janpeak season
  2. Febcommon
  3. Maruncommon
  4. Apruncommon
  5. Mayuncommon
  6. Jununcommon
  7. Juluncommon
  8. Auguncommon
  9. Sepcommon
  10. Octpeak season
  11. Novpeak season
  12. Decpeak season

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

0%0.5%1%1.5%Jan 1-7: 1.2% of 34758 checklistsJan 8-14: 1.1% of 29835 checklistsJan 15-21: 1.2% of 29279 checklistsJan 22-31: 1.0% of 39716 checklistsFeb 1-7: 0.9% of 27299 checklistsFeb 8-14: 0.7% of 28703 checklistsFeb 15-21: 0.5% of 35357 checklistsFeb 22-28: 0.6% of 29889 checklistsMar 1-7: 0.4% of 29932 checklistsMar 8-14: 0.4% of 32982 checklistsMar 15-21: 0.4% of 34731 checklistsMar 22-31: 0.3% of 50213 checklistsApr 1-7: 0.3% of 35788 checklistsApr 8-14: 0.3% of 38087 checklistsApr 15-21: 0.3% of 41520 checklistsApr 22-30: 0.2% of 55218 checklistsMay 1-7: 0.3% of 39688 checklistsMay 8-14: 0.3% of 39398 checklistsMay 15-21: 0.3% of 29562 checklistsMay 22-31: 0.2% of 36774 checklistsJun 1-7: 0.2% of 21313 checklistsJun 8-14: 0.2% of 19129 checklistsJun 15-21: 0.2% of 17922 checklistsJun 22-30: 0.2% of 21188 checklistsJul 1-7: 0.2% of 17325 checklistsJul 8-14: 0.1% of 16463 checklistsJul 15-21: 0.2% of 18642 checklistsJul 22-31: 0.2% of 31215 checklistsAug 1-7: 0.1% of 28163 checklistsAug 8-14: 0.2% of 31329 checklistsAug 15-21: 0.3% of 23878 checklistsAug 22-31: 0.4% of 28508 checklistsSep 1-7: 0.4% of 20878 checklistsSep 8-14: 0.6% of 19671 checklistsSep 15-21: 0.9% of 19859 checklistsSep 22-30: 0.7% of 25179 checklistsOct 1-7: 0.7% of 19420 checklistsOct 8-14: 1.0% of 21925 checklistsOct 15-21: 0.9% of 20995 checklistsOct 22-31: 0.9% of 29258 checklistsNov 1-7: 1.2% of 21269 checklistsNov 8-14: 1.1% of 22753 checklistsNov 15-21: 1.0% of 21982 checklistsNov 22-30: 1.1% of 29475 checklistsDec 1-7: 1.2% of 20810 checklistsDec 8-14: 1.2% of 22229 checklistsDec 15-21: 1.2% of 25148 checklistsDec 22-31: 1.1% of 39567 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 Arizona 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 Arizona

Best counties

Share of checklists at the peak
  1. Pinal CountyBest the second week of December · 724 checklists that week, 40,036 in all5.0%
  2. Yuma CountyBest late October · 386 checklists that week, 14,687 in all3.5%
  3. La Paz CountyBest late December · 311 checklists that week, 7,279 in all3.1%
  4. Greenlee CountyBest early October · 33 checklists that week, 2,745 in all3.1%
  5. Mohave CountyBest the second week of June · 231 checklists that week, 18,083 in all1.8%
  6. Graham CountyBest early December · 130 checklists that week, 9,876 in all1.8%

Best spots

Share of checklists at the peak
  1. Isabella Lee Natural PreservePima County, best the second week of January · 24 checklists that week, 799 in all23%
  2. Cibola National Wildlife RefugeLa Paz County, best late December · 26 checklists that week, 484 in all19%

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

Best time of day

In Arizona, the Prairie Falcon is most often listed on checklists started between 7 and 9 am (0.7% of those checklists).

0%0.5%1%12 am: too few checklists (488) to judge1 am: too few checklists (503) to judge2 am: too few checklists (489) to judge3 am: too few checklists (735) to judge4 am: too few checklists (4115) to judge5 am: 0.4% of 38350 checklists6 am: 0.6% of 118786 checklists7 am: 0.7% of 183415 checklists8 am: 0.7% of 187346 checklists9 am: 0.7% of 151342 checklists10 am: 0.6% of 124522 checklists11 am: 0.6% of 97088 checklists12 pm: 0.5% of 78110 checklists1 pm: 0.5% of 73059 checklists2 pm: 0.5% of 68912 checklists3 pm: 0.5% of 68060 checklists4 pm: 0.4% of 69387 checklists5 pm: 0.3% of 52951 checklists6 pm: 0.2% of 31061 checklists7 pm: too few checklists (16076) to judge8 pm: too few checklists (5352) to judge9 pm: too few checklists (2369) to judge10 pm: too few checklists (1100) to judge11 pm: too few checklists (604) 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
January1.2%1.1%1.2%1.0%
February0.9%0.7%0.5%0.6%
March0.4%0.4%0.4%0.3%
April0.3%0.3%0.3%0.2%
May0.3%0.3%0.3%0.2%
June0.2%0.2%0.2%0.2%
July0.2%0.1%0.2%0.2%
August0.1%0.2%0.3%0.4%
September0.4%0.6%0.9%0.7%
October0.7%1.0%0.9%0.9%
November1.2%1.1%1.0%1.1%
December1.2%1.2%1.2%1.1%

Neighboring states

  • Nevada: arrives mid August, 3 weeks earlier than Arizona
  • Utah: arrives late August, 2 weeks earlier than Arizona
  • Colorado: arrives early June, 13 weeks earlier than Arizona
  • Wyoming: year-round, peaks late July

Common questions

When do Prairie Falcons arrive in Arizona?
Prairie Falcons are winter birds in Arizona: they arrive in the second week of September, peak in the second week of December (1.2% of checklists), and most are gone by early March.
When do Prairie Falcons leave Arizona?
Most Prairie Falcons have left Arizona by early March, when reports fall below half their usual rate.
When is the best time to see a Prairie Falcon in Arizona?
The Prairie Falcon is reported most often in the second week of December, on about 1.2% of Arizona checklists.
Where in Arizona are Prairie Falcons seen most often?
By county, Pinal County, Yuma County, and La Paz County have the highest peak reporting rates for the Prairie Falcon (counties with at least 200 checklists).