WhenToBird

Falco sparverius · Falconidae

When Do American Kestrels Arrive in California?

Adult male American Kestrel
Photo: Jonathan Eisen, CC BY 4.0 via iNaturalist

American Kestrels are in California all year, but most are here in winter: numbers build from mid September, peak in the second week of December (14% of checklists), and fall back by mid February. In the quietest week (the second week of May) they are still on about 4.9% of checklists.

When to look

Numbers buildSep 15-21mid September
PeakDec 8-14the second week of December
Fall back byFeb 15-21mid February
FewestMay 8-14the second week of May

Best: the second week of December. Here all year; numbers build from mid September and fall back by mid February. Peak: on about 14% of California checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marcommon
  4. Aprcommon
  5. Mayuncommon
  6. Jununcommon
  7. Juluncommon
  8. Augcommon
  9. Seppeak season
  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: 14% of 112336 checklistsJan 8-14: 13% of 85518 checklistsJan 15-21: 13% of 86488 checklistsJan 22-31: 13% of 116174 checklistsFeb 1-7: 12% of 75171 checklistsFeb 8-14: 10% of 84467 checklistsFeb 15-21: 9.2% of 105683 checklistsFeb 22-28: 9.8% of 83396 checklistsMar 1-7: 9.2% of 77470 checklistsMar 8-14: 8.6% of 75180 checklistsMar 15-21: 7.8% of 80770 checklistsMar 22-31: 7.0% of 114116 checklistsApr 1-7: 6.0% of 84057 checklistsApr 8-14: 5.7% of 83692 checklistsApr 15-21: 5.3% of 89242 checklistsApr 22-30: 5.1% of 114289 checklistsMay 1-7: 4.9% of 85728 checklistsMay 8-14: 4.7% of 91984 checklistsMay 15-21: 5.1% of 75478 checklistsMay 22-31: 5.3% of 106250 checklistsJun 1-7: 5.1% of 70051 checklistsJun 8-14: 5.1% of 67485 checklistsJun 15-21: 5.4% of 66269 checklistsJun 22-30: 5.1% of 79172 checklistsJul 1-7: 4.8% of 62877 checklistsJul 8-14: 4.9% of 60328 checklistsJul 15-21: 5.1% of 59705 checklistsJul 22-31: 5.3% of 83796 checklistsAug 1-7: 5.7% of 60215 checklistsAug 8-14: 6.4% of 60172 checklistsAug 15-21: 6.6% of 59877 checklistsAug 22-31: 7.5% of 89107 checklistsSep 1-7: 8.5% of 72000 checklistsSep 8-14: 9.6% of 71228 checklistsSep 15-21: 10% of 76808 checklistsSep 22-30: 11% of 100204 checklistsOct 1-7: 11% of 76571 checklistsOct 8-14: 12% of 80874 checklistsOct 15-21: 12% of 74581 checklistsOct 22-31: 13% of 97498 checklistsNov 1-7: 13% of 70851 checklistsNov 8-14: 13% of 72431 checklistsNov 15-21: 14% of 66767 checklistsNov 22-30: 14% of 94737 checklistsDec 1-7: 14% of 65393 checklistsDec 8-14: 14% of 67449 checklistsDec 15-21: 15% of 83421 checklistsDec 22-31: 14% of 124993 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 California 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 California

Best counties

Share of checklists at the peak
  1. Imperial CountyBest early January · 833 checklists that week, 24,551 in all46%
  2. Merced CountyBest early December · 282 checklists that week, 13,095 in all42%
  3. Colusa CountyBest late November · 251 checklists that week, 7,653 in all41%
  4. Sutter CountyBest mid December · 200 checklists that week, 4,996 in all36%
  5. Yuba CountyBest the second week of December · 111 checklists that week, 6,013 in all33%
  6. Solano CountyBest early December · 407 checklists that week, 25,325 in all32%

Best spots

Share of checklists at the peak
  1. Harmony Headlands State ParkSan Luis Obispo County, best late November · 29 checklists that week, 681 in all96%
  2. La Honda Creek Open Space PreserveSan Mateo County, best mid January · 31 checklists that week, 882 in all94%
  3. Ramona Grasslands Preserve (Santa Maria Valley)San Diego County, best the second week of November · 23 checklists that week, 109 in all92%
  4. Tolay Lake Regional ParkSonoma County, best the second week of December · 37 checklists that week, 1,188 in all91%

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

Best time of day

In California, the American Kestrel is most often listed on checklists started between 7 and 9 am (10% of those checklists).

0%5%10%15%12 am: too few checklists (1688) to judge1 am: too few checklists (1451) to judge2 am: too few checklists (1402) to judge3 am: too few checklists (1743) to judge4 am: too few checklists (4647) to judge5 am: too few checklists (32158) to judge6 am: 9.2% of 186053 checklists7 am: 10% of 444086 checklists8 am: 11% of 535846 checklists9 am: 9.8% of 486061 checklists10 am: 9.6% of 411130 checklists11 am: 9.4% of 325798 checklists12 pm: 9.0% of 269132 checklists1 pm: 9.3% of 244762 checklists2 pm: 9.3% of 235420 checklists3 pm: 8.9% of 232365 checklists4 pm: 7.3% of 208688 checklists5 pm: 6.1% of 146104 checklists6 pm: 4.6% of 96867 checklists7 pm: too few checklists (50942) to judge8 pm: too few checklists (14803) to judge9 pm: too few checklists (5561) to judge10 pm: too few checklists (3546) to judge11 pm: too few checklists (2092) 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
January14%13%13%13%
February12%10%9.2%9.8%
March9.2%8.6%7.8%7.0%
April6.0%5.7%5.3%5.1%
May4.9%4.7%5.1%5.3%
June5.1%5.1%5.4%5.1%
July4.8%4.9%5.1%5.3%
August5.7%6.4%6.6%7.5%
September8.5%9.6%10%11%
October11%12%12%13%
November13%13%14%14%
December14%14%15%14%

Neighboring states

  • Nevada: year-round, peaks the second week of September
  • Utah: arrives early November, 6 weeks later than California
  • Arizona: arrives early September, 2 weeks earlier than California
  • Oregon: year-round, peaks late December

Common questions

When do American Kestrels arrive in California?
American Kestrels are in California all year, but most are here in winter: numbers build from mid September, peak in the second week of December (14% of checklists), and fall back by mid February. In the quietest week (the second week of May) they are still on about 4.9% of checklists.
When do American Kestrels leave California?
American Kestrels never fully leave California: numbers fall back below half their usual rate by mid February, but some are still reported in every week, about 4.9% of checklists at the low.
When is the best time to see a American Kestrel in California?
The American Kestrel is reported most often in the second week of December, on about 14% of California checklists.
Where in California are American Kestrels seen most often?
By county, Imperial County, Merced County, and Colusa County have the highest peak reporting rates for the American Kestrel (counties with at least 200 checklists).