WhenToBird

Cyanocitta cristata · Corvidae

When Do Blue Jays Arrive in Pennsylvania?

Adult Blue Jay
Photo: Texas Bird Family, CC BY 4.0 via iNaturalist

The Blue Jay is in Pennsylvania all year. It turns up on about 77% of checklists at its peak (late September) and on 37% in its quietest week (early March).

When to look

PresentAll year
Peak weekSep 22-30late September
Quietest weekMar 1-7early March

Best: late September. Here all year. Peak: on about 77% of Pennsylvania checklists.

  1. Jancommon
  2. Febcommon
  3. Marcommon
  4. Aprcommon
  5. Maypeak season
  6. Juncommon
  7. Julcommon
  8. Augpeak season
  9. Seppeak season
  10. Octpeak season
  11. Novpeak season
  12. Deccommon

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

0%20%40%60%80%Jan 1-7: 38% of 47145 checklistsJan 8-14: 38% of 35840 checklistsJan 15-21: 38% of 35423 checklistsJan 22-31: 39% of 49126 checklistsFeb 1-7: 38% of 36366 checklistsFeb 8-14: 39% of 42248 checklistsFeb 15-21: 38% of 55888 checklistsFeb 22-28: 38% of 42050 checklistsMar 1-7: 37% of 42709 checklistsMar 8-14: 37% of 43985 checklistsMar 15-21: 40% of 44547 checklistsMar 22-31: 42% of 66940 checklistsApr 1-7: 44% of 51147 checklistsApr 8-14: 46% of 54868 checklistsApr 15-21: 50% of 57252 checklistsApr 22-30: 59% of 81727 checklistsMay 1-7: 60% of 76472 checklistsMay 8-14: 57% of 79341 checklistsMay 15-21: 54% of 61724 checklistsMay 22-31: 49% of 70722 checklistsJun 1-7: 47% of 45652 checklistsJun 8-14: 45% of 41810 checklistsJun 15-21: 45% of 38973 checklistsJun 22-30: 46% of 44255 checklistsJul 1-7: 48% of 34822 checklistsJul 8-14: 48% of 31104 checklistsJul 15-21: 48% of 29262 checklistsJul 22-31: 49% of 41436 checklistsAug 1-7: 51% of 29189 checklistsAug 8-14: 53% of 28840 checklistsAug 15-21: 55% of 29948 checklistsAug 22-31: 60% of 48235 checklistsSep 1-7: 66% of 37175 checklistsSep 8-14: 72% of 36527 checklistsSep 15-21: 77% of 37261 checklistsSep 22-30: 77% of 43583 checklistsOct 1-7: 77% of 35352 checklistsOct 8-14: 73% of 35560 checklistsOct 15-21: 70% of 33119 checklistsOct 22-31: 65% of 44654 checklistsNov 1-7: 60% of 32965 checklistsNov 8-14: 55% of 31305 checklistsNov 15-21: 51% of 29471 checklistsNov 22-30: 48% of 38642 checklistsDec 1-7: 46% of 28779 checklistsDec 8-14: 45% of 29486 checklistsDec 15-21: 45% of 37465 checklistsDec 22-31: 45% 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. Fulton CountyBest early October · 83 checklists that week, 7,004 in all89%
  2. Montour CountyBest the second week of October · 70 checklists that week, 6,082 in all87%
  3. Beaver CountyBest late September · 155 checklists that week, 8,775 in all86%
  4. Luzerne CountyBest late September · 642 checklists that week, 34,996 in all85%
  5. Sullivan CountyBest late September · 75 checklists that week, 4,362 in all85%
  6. Bucks CountyBest mid September · 1853 checklists that week, 95,030 in all84%

Best spots

Share of checklists at the peak
  1. Owls Nest ParkBucks County, best the second week of September · 21 checklists that week, 708 in all100%
  2. Hatfield Township Nature AreaMontgomery County, best late April · 21 checklists that week, 242 in all100%
  3. Swatara State ParkSchuylkill County, best late September · 26 checklists that week, 1,376 in all100%
  4. Black Rock SanctuaryChester County, best early September · 23 checklists that week, 1,275 in all100%
  5. Hartwood Acres ParkAllegheny County, best late October · 23 checklists that week, 475 in all100%
  6. Doylestown Bike & Hike PathBucks County, best late April · 21 checklists that week, 779 in all100%

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

Best time of day

In Pennsylvania, the Blue Jay is most often listed on checklists started between 6 and 8 am (66% of those checklists).

0%20%40%60%80%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: 65% of 92903 checklists7 am: 67% of 241233 checklists8 am: 65% of 271994 checklists9 am: 59% of 236842 checklists10 am: 53% of 199508 checklists11 am: 48% of 161893 checklists12 pm: 45% of 143945 checklists1 pm: 43% of 134352 checklists2 pm: 39% of 129692 checklists3 pm: 35% of 126132 checklists4 pm: 35% of 115055 checklists5 pm: 42% of 90719 checklists6 pm: 40% of 67534 checklists7 pm: 31% 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
January38%38%38%39%
February38%39%38%38%
March37%37%40%42%
April44%46%50%59%
May60%57%54%49%
June47%45%45%46%
July48%48%48%49%
August51%53%55%60%
September66%72%77%77%
October77%73%70%65%
November60%55%51%48%
December46%45%45%45%

Neighboring states

Common questions

When do Blue Jays arrive in Pennsylvania?
The Blue Jay is in Pennsylvania all year. It turns up on about 77% of checklists at its peak (late September) and on 37% in its quietest week (early March).
When do Blue Jays leave Pennsylvania?
The Blue Jay does not leave Pennsylvania: it is reported all year, from 37% of checklists in early March to 77% in late September.
When is the best time to see a Blue Jay in Pennsylvania?
The Blue Jay is reported most often in late September, on about 77% of Pennsylvania checklists.
Where in Pennsylvania are Blue Jays seen most often?
By county, Fulton County, Montour County, and Beaver County have the highest peak reporting rates for the Blue Jay (counties with at least 200 checklists).