WhenToBird

Corthylio calendula · Regulidae

When Do Ruby-crowned Kinglets Arrive in California?

Adult male Ruby-crowned Kinglet
Photo: Jonathan Eisen, CC BY 4.0 via iNaturalist

Ruby-crowned Kinglets are winter birds in California: the first arrive in mid September, they are common by the second week of October, peak in the second week of December (37% of checklists), and most are gone by early April.

When to look

First arrivalsSep 15-21mid September
Common byOct 8-14the second week of October
PeakDec 8-14the second week of December
Most gone byApr 1-7early April

Best: the second week of December. First arrivals mid September; most are gone by early April. Peak: on about 37% of California checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marcommon
  4. Aprcommon
  5. Maynot usually seen
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepuncommon
  10. Octpeak season
  11. Novpeak season
  12. Decpeak season

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

0%10%20%30%40%Jan 1-7: 32% of 112336 checklistsJan 8-14: 30% of 85518 checklistsJan 15-21: 30% of 86488 checklistsJan 22-31: 30% of 116174 checklistsFeb 1-7: 28% of 75171 checklistsFeb 8-14: 27% of 84467 checklistsFeb 15-21: 24% of 105683 checklistsFeb 22-28: 26% of 83396 checklistsMar 1-7: 25% of 77470 checklistsMar 8-14: 26% of 75180 checklistsMar 15-21: 25% of 80770 checklistsMar 22-31: 22% of 114116 checklistsApr 1-7: 16% of 84057 checklistsApr 8-14: 10% of 83692 checklistsApr 15-21: 5.5% of 89242 checklistsApr 22-30: 2.5% of 114289 checklistsMay 1-7: 0.9% of 85728 checklistsMay 8-14: 0.4% of 91984 checklistsMay 15-21: 0.2% of 75478 checklistsMay 22-31: 0.1% of 106250 checklistsJun 1-7: 0.1% of 70051 checklistsJun 8-14: 0.2% of 67485 checklistsJun 15-21: 0.2% of 66269 checklistsJun 22-30: 0.2% of 79172 checklistsJul 1-7: 0.2% of 62877 checklistsJul 8-14: 0.1% of 60328 checklistsJul 15-21: 0.1% of 59705 checklistsJul 22-31: 0.1% of 83796 checklistsAug 1-7: 0.1% of 60215 checklistsAug 8-14: 0.1% of 60172 checklistsAug 15-21: 0.1% of 59877 checklistsAug 22-31: 0.1% of 89107 checklistsSep 1-7: 0.2% of 72000 checklistsSep 8-14: 0.5% of 71228 checklistsSep 15-21: 1.9% of 76808 checklistsSep 22-30: 7.5% of 100204 checklistsOct 1-7: 15% of 76571 checklistsOct 8-14: 22% of 80874 checklistsOct 15-21: 29% of 74581 checklistsOct 22-31: 33% of 97498 checklistsNov 1-7: 35% of 70851 checklistsNov 8-14: 35% of 72431 checklistsNov 15-21: 35% of 66767 checklistsNov 22-30: 36% of 94737 checklistsDec 1-7: 37% of 65393 checklistsDec 8-14: 37% of 67449 checklistsDec 15-21: 39% of 83421 checklistsDec 22-31: 34% 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. Nevada CountyBest the second week of December · 294 checklists that week, 25,896 in all62%
  2. Trinity CountyBest mid November · 193 checklists that week, 9,037 in all54%
  3. Contra Costa CountyBest the second week of December · 2111 checklists that week, 115,071 in all53%
  4. Sacramento CountyBest the second week of December · 2103 checklists that week, 121,767 in all52%
  5. Fresno CountyBest the second week of December · 427 checklists that week, 29,788 in all50%
  6. Tulare CountyBest the second week of December · 384 checklists that week, 28,366 in all49%

Best spots

Share of checklists at the peak
  1. Bobelaine SanctuarySutter County, best the second week of November · 32 checklists that week, 762 in all100%
  2. Harrison ParkAlameda County, best late November · 39 checklists that week, 288 in all100%
  3. Joseph Reichmuth ParkSacramento County, best the second week of December · 29 checklists that week, 1,446 in all99%
  4. Camanche ReservoirSan Joaquin County, best late December · 21 checklists that week, 678 in all97%
  5. American River Parkway (west 2)Sacramento County, best late October · 26 checklists that week, 633 in all97%

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

Best time of day

In California, the Ruby-crowned Kinglet is most often listed on checklists started between 8 and 10 am (20% of those checklists).

0%10%20%30%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: 11% of 186053 checklists7 am: 20% of 444086 checklists8 am: 21% of 535846 checklists9 am: 20% of 486061 checklists10 am: 19% of 411130 checklists11 am: 18% of 325798 checklists12 pm: 17% of 269132 checklists1 pm: 17% of 244762 checklists2 pm: 17% of 235420 checklists3 pm: 16% of 232365 checklists4 pm: 12% of 208688 checklists5 pm: 5.8% of 146104 checklists6 pm: 1.9% 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
January32%30%30%30%
February28%27%24%26%
March25%26%25%22%
April16%10%5.5%2.5%
May0.9%0.4%0.2%0.1%
June0.1%0.2%0.2%0.2%
July0.2%0.1%0.1%0.1%
August0.1%0.1%0.1%0.1%
September0.2%0.5%1.9%7.5%
October15%22%29%33%
November35%35%35%36%
December37%37%39%34%

Neighboring states

  • Nevada: arrives the second week of August, 5 weeks earlier than California
  • Utah: arrives late September, 1 week later than California
  • Arizona: arrives mid September, in the same week than California
  • Oregon: arrives the second week of September, 1 week earlier than California

Common questions

When do Ruby-crowned Kinglets arrive in California?
Ruby-crowned Kinglets are winter birds in California: the first arrive in mid September, they are common by the second week of October, peak in the second week of December (37% of checklists), and most are gone by early April.
When do Ruby-crowned Kinglets leave California?
Most Ruby-crowned Kinglets have left California by early April, when reports fall below half their usual rate. Stragglers are still reported until mid April.
When is the best time to see a Ruby-crowned Kinglet in California?
The Ruby-crowned Kinglet is reported most often in the second week of December, on about 37% of California checklists.
Where in California are Ruby-crowned Kinglets seen most often?
By county, Nevada County, Trinity County, and Contra Costa County have the highest peak reporting rates for the Ruby-crowned Kinglet (counties with at least 200 checklists).