WhenToBird

Sialia sialis · Turdidae

When Do Eastern Bluebirds Arrive in Pennsylvania?

Adult male Eastern Bluebird
Photo: Dan Vickers, CC BY 4.0 via iNaturalist

The Eastern Bluebird is in Pennsylvania all year. It turns up on about 23% of checklists at its peak (late October) and on 14% in its quietest week (late August).

When to look

PresentAll year
Peak weekOct 22-31late October
Quietest weekAug 22-31late August

Best: late October. Here all year. Peak: on about 23% of Pennsylvania checklists.

  1. Jancommon
  2. Febpeak season
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julpeak season
  8. Augcommon
  9. Seppeak season
  10. Octpeak season
  11. Novpeak season
  12. Decpeak season

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

0%10%20%30%Jan 1-7: 16% of 47145 checklistsJan 8-14: 15% of 35840 checklistsJan 15-21: 14% of 35423 checklistsJan 22-31: 15% of 49126 checklistsFeb 1-7: 16% of 36366 checklistsFeb 8-14: 17% of 42248 checklistsFeb 15-21: 18% of 55888 checklistsFeb 22-28: 21% of 42050 checklistsMar 1-7: 22% of 42709 checklistsMar 8-14: 23% of 43985 checklistsMar 15-21: 23% of 44547 checklistsMar 22-31: 23% of 66940 checklistsApr 1-7: 23% of 51147 checklistsApr 8-14: 24% of 54868 checklistsApr 15-21: 22% of 57252 checklistsApr 22-30: 22% of 81727 checklistsMay 1-7: 21% of 76472 checklistsMay 8-14: 21% of 79341 checklistsMay 15-21: 21% of 61724 checklistsMay 22-31: 20% of 70722 checklistsJun 1-7: 20% of 45652 checklistsJun 8-14: 19% of 41810 checklistsJun 15-21: 19% of 38973 checklistsJun 22-30: 19% of 44255 checklistsJul 1-7: 19% of 34822 checklistsJul 8-14: 19% of 31104 checklistsJul 15-21: 18% of 29262 checklistsJul 22-31: 17% of 41436 checklistsAug 1-7: 16% of 29189 checklistsAug 8-14: 16% of 28840 checklistsAug 15-21: 15% of 29948 checklistsAug 22-31: 14% of 48235 checklistsSep 1-7: 14% of 37175 checklistsSep 8-14: 15% of 36527 checklistsSep 15-21: 16% of 37261 checklistsSep 22-30: 18% of 43583 checklistsOct 1-7: 21% of 35352 checklistsOct 8-14: 21% of 35560 checklistsOct 15-21: 23% of 33119 checklistsOct 22-31: 23% of 44654 checklistsNov 1-7: 24% of 32965 checklistsNov 8-14: 21% of 31305 checklistsNov 15-21: 20% of 29471 checklistsNov 22-30: 19% of 38642 checklistsDec 1-7: 17% of 28779 checklistsDec 8-14: 17% of 29486 checklistsDec 15-21: 17% of 37465 checklistsDec 22-31: 18% 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. Juniata CountyBest mid June · 141 checklists that week, 9,807 in all58%
  2. Chester CountyBest late March · 4084 checklists that week, 144,121 in all47%
  3. Perry CountyBest the second week of April · 260 checklists that week, 10,281 in all45%
  4. Fulton CountyBest late February · 163 checklists that week, 7,004 in all42%
  5. Cumberland CountyBest the second week of March · 970 checklists that week, 50,879 in all40%
  6. Greene CountyBest the second week of July · 50 checklists that week, 2,997 in all39%

Best spots

Share of checklists at the peak
  1. Susquehannock State ParkLancaster County, best the second week of June · 36 checklists that week, 1,999 in all94%
  2. ChesLen PreserveChester County, best mid March · 41 checklists that week, 2,150 in all92%
  3. State Game Land 290Dauphin County, best the second week of April · 24 checklists that week, 890 in all92%
  4. Green Hills PreserveBerks County, best early May · 20 checklists that week, 559 in all91%

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

Best time of day

In Pennsylvania, the Eastern Bluebird is most often listed on checklists started between 7 and 9 am (25% of those checklists).

0%10%20%30%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: 23% of 92903 checklists7 am: 25% of 241233 checklists8 am: 25% of 271994 checklists9 am: 22% of 236842 checklists10 am: 20% of 199508 checklists11 am: 17% of 161893 checklists12 pm: 16% of 143945 checklists1 pm: 16% of 134352 checklists2 pm: 16% of 129692 checklists3 pm: 16% of 126132 checklists4 pm: 14% of 115055 checklists5 pm: 16% of 90719 checklists6 pm: 16% of 67534 checklists7 pm: 13% 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
January16%15%14%15%
February16%17%18%21%
March22%23%23%23%
April23%24%22%22%
May21%21%21%20%
June20%19%19%19%
July19%19%18%17%
August16%16%15%14%
September14%15%16%18%
October21%21%23%23%
November24%21%20%19%
December17%17%17%18%

Neighboring states

Common questions

When do Eastern Bluebirds arrive in Pennsylvania?
The Eastern Bluebird is in Pennsylvania all year. It turns up on about 23% of checklists at its peak (late October) and on 14% in its quietest week (late August).
When do Eastern Bluebirds leave Pennsylvania?
The Eastern Bluebird does not leave Pennsylvania: it is reported all year, from 14% of checklists in late August to 23% in late October.
When is the best time to see a Eastern Bluebird in Pennsylvania?
The Eastern Bluebird is reported most often in late October, on about 23% of Pennsylvania checklists.
Where in Pennsylvania are Eastern Bluebirds seen most often?
By county, Juniata County, Chester County, and Perry County have the highest peak reporting rates for the Eastern Bluebird (counties with at least 200 checklists).