WhenToBird

Corthylio calendula · Regulidae

When Do Ruby-crowned Kinglets Arrive in Pennsylvania?

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

Ruby-crowned Kinglets are winter birds in Pennsylvania: the first arrive in the second week of September, they are common by mid September, peak in mid October (26% of checklists), and most are gone by mid May.

When to look

First arrivalsSep 8-14the second week of September
Common bySep 15-21mid September
PeakOct 15-21mid October
Most gone byMay 15-21mid May

Best: mid October. First arrivals the second week of September; most are gone by mid May. Peak: on about 26% of Pennsylvania checklists.

  1. Janrare
  2. Febrare
  3. Marrare
  4. Aprcommon
  5. Maycommon
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepuncommon
  10. Octpeak season
  11. Novcommon
  12. Decuncommon

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

0%10%20%30%Jan 1-7: 3.0% of 47145 checklistsJan 8-14: 3.0% of 35840 checklistsJan 15-21: 2.4% of 35423 checklistsJan 22-31: 2.3% of 49126 checklistsFeb 1-7: 2.2% of 36366 checklistsFeb 8-14: 2.0% of 42248 checklistsFeb 15-21: 1.5% of 55888 checklistsFeb 22-28: 1.8% of 42050 checklistsMar 1-7: 1.5% of 42709 checklistsMar 8-14: 1.5% of 43985 checklistsMar 15-21: 2.1% of 44547 checklistsMar 22-31: 2.6% of 66940 checklistsApr 1-7: 6.0% of 51147 checklistsApr 8-14: 15% of 54868 checklistsApr 15-21: 23% of 57252 checklistsApr 22-30: 19% of 81727 checklistsMay 1-7: 11% of 76472 checklistsMay 8-14: 4.8% of 79341 checklistsMay 15-21: 0.5% of 61724 checklistsMay 22-31: 0.1% of 70722 checklistsJun 1-7: 0% of 45652 checklistsJun 8-14: 0.1% of 41810 checklistsJun 15-21: 0.1% of 38973 checklistsJun 22-30: 0% of 44255 checklistsJul 1-7: 0% of 34822 checklistsJul 8-14: 0.1% of 31104 checklistsJul 15-21: 0% of 29262 checklistsJul 22-31: 0% of 41436 checklistsAug 1-7: 0% of 29189 checklistsAug 8-14: 0.1% of 28840 checklistsAug 15-21: 0.1% of 29948 checklistsAug 22-31: 0.1% of 48235 checklistsSep 1-7: 0.1% of 37175 checklistsSep 8-14: 0.4% of 36527 checklistsSep 15-21: 2.8% of 37261 checklistsSep 22-30: 8.9% of 43583 checklistsOct 1-7: 19% of 35352 checklistsOct 8-14: 25% of 35560 checklistsOct 15-21: 29% of 33119 checklistsOct 22-31: 23% of 44654 checklistsNov 1-7: 13% of 32965 checklistsNov 8-14: 6.9% of 31305 checklistsNov 15-21: 4.6% of 29471 checklistsNov 22-30: 4.3% of 38642 checklistsDec 1-7: 3.5% of 28779 checklistsDec 8-14: 3.6% of 29486 checklistsDec 15-21: 3.5% of 37465 checklistsDec 22-31: 3.3% of 50651 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 Pennsylvania 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 Pennsylvania

Best counties

Share of checklists at the peak
  1. Philadelphia CountyBest mid October · 1681 checklists that week, 96,503 in all42%
  2. Bucks CountyBest mid October · 1747 checklists that week, 95,030 in all40%
  3. Chester CountyBest mid October · 2363 checklists that week, 144,121 in all38%
  4. Wayne CountyBest the second week of October · 157 checklists that week, 10,444 in all38%
  5. Fulton CountyBest the second week of October · 73 checklists that week, 7,004 in all35%
  6. Schuylkill CountyBest the second week of October · 384 checklists that week, 22,261 in all34%

Best spots

Share of checklists at the peak
  1. Locust Lake State ParkSchuylkill County, best mid October · 20 checklists that week, 919 in all89%
  2. Blue Spruce ParkIndiana County, best the second week of October · 28 checklists that week, 667 in all87%
  3. State Game Land 156Lancaster County, best the second week of April · 23 checklists that week, 601 in all86%
  4. Union Twp. Recreation AreaBerks County, best late October · 22 checklists that week, 729 in all84%
  5. Lower LakeMonroe County, best the second week of October · 23 checklists that week, 1,218 in all82%
  6. Owls Nest ParkBucks County, best late October · 23 checklists that week, 708 in all82%

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

Best time of day

In Pennsylvania, the Ruby-crowned Kinglet is most often listed on checklists started between 7 and 9 am (8.1% of those checklists).

0%5%10%12 am: too few checklists (1558) to judge1 am: too few checklists (1136) to judge2 am: too few checklists (839) to judge3 am: too few checklists (842) to judge4 am: too few checklists (2550) to judge5 am: too few checklists (18294) to judge6 am: 7.0% of 92903 checklists7 am: 8.2% of 241233 checklists8 am: 8.0% of 271994 checklists9 am: 6.8% of 236842 checklists10 am: 5.8% of 199508 checklists11 am: 5.1% of 161893 checklists12 pm: 4.8% of 143945 checklists1 pm: 4.7% of 134352 checklists2 pm: 4.5% of 129692 checklists3 pm: 4.4% of 126132 checklists4 pm: 4.2% of 115055 checklists5 pm: 4.1% of 90719 checklists6 pm: 2.0% of 67534 checklists7 pm: 0.7% of 43004 checklists8 pm: too few checklists (13966) to judge9 pm: too few checklists (3913) to judge10 pm: too few checklists (1989) to judge11 pm: too few checklists (1146) 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
January3.0%3.0%2.4%2.3%
February2.2%2.0%1.5%1.8%
March1.5%1.5%2.1%2.6%
April6.0%15%23%19%
May11%4.8%0.5%0.1%
June0%0.1%0.1%0%
July0%0.1%0%0%
August0%0.1%0.1%0.1%
September0.1%0.4%2.8%8.9%
October19%25%29%23%
November13%6.9%4.6%4.3%
December3.5%3.6%3.5%3.3%

Neighboring states

  • Maryland: arrives the second week of September, in the same week than Pennsylvania
  • District of Columbia: arrives mid September, 1 week later than Pennsylvania
  • Delaware: arrives the second week of September, in the same week than Pennsylvania
  • New Jersey: arrives the second week of September, in the same week than Pennsylvania

Common questions

When do Ruby-crowned Kinglets arrive in Pennsylvania?
Ruby-crowned Kinglets are winter birds in Pennsylvania: the first arrive in the second week of September, they are common by mid September, peak in mid October (26% of checklists), and most are gone by mid May.
When do Ruby-crowned Kinglets leave Pennsylvania?
Most Ruby-crowned Kinglets have left Pennsylvania by mid May, when reports fall below half their usual rate.
When is the best time to see a Ruby-crowned Kinglet in Pennsylvania?
The Ruby-crowned Kinglet is reported most often in mid October, on about 26% of Pennsylvania checklists.
Where in Pennsylvania are Ruby-crowned Kinglets seen most often?
By county, Philadelphia County, Bucks County, and Chester County have the highest peak reporting rates for the Ruby-crowned Kinglet (counties with at least 200 checklists).