WhenToBird

Setophaga tigrina · Parulidae

When Do Cape May Warblers Arrive in Pennsylvania?

Adult male Cape May Warbler
Photo: Mike Mulqueen, CC0 1.0 via iNaturalist

Cape May Warblers mostly pass through Pennsylvania: they arrive in early August, peak in mid September (7.1% of checklists), and most are gone by late November.

When to look

First arrivalsAug 1-7early August
Common byAug 1-7early August
PeakSep 15-21mid September
Most gone byNov 22-30late November

Best: mid September. First arrivals early August; most are gone by late November. Peak: on about 7.1% of Pennsylvania checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Apruncommon
  5. Maycommon
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augcommon
  9. Seppeak season
  10. Octcommon
  11. Novnot usually seen
  12. Decnot usually seen

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

0%2%4%6%8%Jan 1-7: 0.1% of 47145 checklistsJan 8-14: 0.1% of 35840 checklistsJan 15-21: 0.1% of 35423 checklistsJan 22-31: 0.1% of 49126 checklistsFeb 1-7: 0.1% of 36366 checklistsFeb 8-14: 0.1% of 42248 checklistsFeb 15-21: 0.1% of 55888 checklistsFeb 22-28: 0.1% of 42050 checklistsMar 1-7: 0.1% of 42709 checklistsMar 8-14: 0.1% of 43985 checklistsMar 15-21: 0.1% of 44547 checklistsMar 22-31: 0.1% of 66940 checklistsApr 1-7: 0.1% of 51147 checklistsApr 8-14: 0.1% of 54868 checklistsApr 15-21: 0.1% of 57252 checklistsApr 22-30: 0.2% of 81727 checklistsMay 1-7: 3.0% of 76472 checklistsMay 8-14: 4.5% of 79341 checklistsMay 15-21: 2.3% of 61724 checklistsMay 22-31: 0.2% of 70722 checklistsJun 1-7: 0% of 45652 checklistsJun 8-14: 0.1% of 41810 checklistsJun 15-21: 0% of 38973 checklistsJun 22-30: 0% of 44255 checklistsJul 1-7: 0% of 34822 checklistsJul 8-14: 0% of 31104 checklistsJul 15-21: 0% of 29262 checklistsJul 22-31: 0.1% of 41436 checklistsAug 1-7: 0.1% of 29189 checklistsAug 8-14: 0.1% of 28840 checklistsAug 15-21: 0.5% of 29948 checklistsAug 22-31: 3.0% of 48235 checklistsSep 1-7: 5.5% of 37175 checklistsSep 8-14: 7.3% of 36527 checklistsSep 15-21: 7.7% of 37261 checklistsSep 22-30: 6.4% of 43583 checklistsOct 1-7: 4.3% of 35352 checklistsOct 8-14: 1.7% of 35560 checklistsOct 15-21: 0.5% of 33119 checklistsOct 22-31: 0.1% of 44654 checklistsNov 1-7: 0.1% of 32965 checklistsNov 8-14: 0.1% of 31305 checklistsNov 15-21: 0.1% of 29471 checklistsNov 22-30: 0.1% of 38642 checklistsDec 1-7: 0.1% of 28779 checklistsDec 8-14: 0.1% of 29486 checklistsDec 15-21: 0.1% of 37465 checklistsDec 22-31: 0.1% 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. Somerset CountyBest the second week of September · 192 checklists that week, 11,903 in all21%
  2. Fulton CountyBest the second week of September · 101 checklists that week, 7,004 in all19%
  3. Clarion CountyBest mid September · 131 checklists that week, 9,153 in all19%
  4. Wayne CountyBest the second week of September · 121 checklists that week, 10,444 in all18%
  5. Warren CountyBest mid September · 57 checklists that week, 5,449 in all16%
  6. Schuylkill CountyBest mid September · 519 checklists that week, 22,261 in all16%

Best spots

Share of checklists at the peak
  1. Antietam Lake ParkBerks County, best the second week of September · 32 checklists that week, 515 in all55%
  2. Hall PondLycoming County, best the second week of September · 46 checklists that week, 1,740 in all52%
  3. Schuylkill Rowing Basin (Lemon Hill)Philadelphia County, best the second week of September · 21 checklists that week, 419 in all45%
  4. Green Lane Reservoir (Pennsburg)Montgomery County, best mid September · 82 checklists that week, 3,842 in all44%
  5. Seeickley Heights Borough ParkAllegheny County, best the second week of September · 121 checklists that week, 1,374 in all43%
  6. Deer Lakes ParkAllegheny County, best the second week of September · 34 checklists that week, 725 in all41%

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

Best time of day

In Pennsylvania, the Cape May Warbler is most often listed on checklists started between 6 and 8 am (2.2% of those checklists).

0%1%2%3%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: 2.4% of 92903 checklists7 am: 2.1% of 241233 checklists8 am: 1.6% of 271994 checklists9 am: 1.1% of 236842 checklists10 am: 0.8% of 199508 checklists11 am: 0.6% of 161893 checklists12 pm: 0.6% of 143945 checklists1 pm: 0.5% of 134352 checklists2 pm: 0.5% of 129692 checklists3 pm: 0.5% of 126132 checklists4 pm: 0.6% of 115055 checklists5 pm: 0.9% of 90719 checklists6 pm: 0.7% of 67534 checklists7 pm: 0.2% 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
January0.1%0.1%0.1%0.1%
February0.1%0.1%0.1%0.1%
March0.1%0.1%0.1%0.1%
April0.1%0.1%0.1%0.2%
May3.0%4.5%2.3%0.2%
June0%0.1%0%0%
July0%0%0%0.1%
August0.1%0.1%0.5%3.0%
September5.5%7.3%7.7%6.4%
October4.3%1.7%0.5%0.1%
November0.1%0.1%0.1%0.1%
December0.1%0.1%0.1%0.1%

Neighboring states

  • Maryland: arrives early August, in the same week than Pennsylvania
  • District of Columbia: arrives mid August, 2 weeks later than Pennsylvania
  • Delaware: arrives late August, 3 weeks later than Pennsylvania
  • New Jersey: arrives mid August, 2 weeks later than Pennsylvania

Common questions

When do Cape May Warblers arrive in Pennsylvania?
Cape May Warblers mostly pass through Pennsylvania: they arrive in early August, peak in mid September (7.1% of checklists), and most are gone by late November.
When do Cape May Warblers leave Pennsylvania?
Most Cape May Warblers have left Pennsylvania by late November, when reports fall below half their usual rate.
When is the best time to see a Cape May Warbler in Pennsylvania?
The Cape May Warbler is reported most often in mid September, on about 7.1% of Pennsylvania checklists.
Where in Pennsylvania are Cape May Warblers seen most often?
By county, Somerset County, Fulton County, and Clarion County have the highest peak reporting rates for the Cape May Warbler (counties with at least 200 checklists).