WhenToBird

Calidris melanotos · Scolopacidae

When Do Pectoral Sandpipers Arrive in Pennsylvania?

Adult Pectoral Sandpiper
Photo: Peter Chen 2.0, CC BY 4.0 via iNaturalist

Pectoral Sandpipers arrive in Pennsylvania in late July, peak in early September (1.8% of checklists), and most are gone by early November.

When to look

First arrivalsJul 22-31late July
Common byJul 22-31late July
PeakSep 1-7early September
Most gone byNov 1-7early November

Best: early September. First arrivals late July; most are gone by early November. Peak: on about 1.8% of Pennsylvania checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Maruncommon
  4. Apruncommon
  5. Mayuncommon
  6. Junnot usually seen
  7. Julcommon
  8. Augpeak season
  9. Seppeak season
  10. Octpeak season
  11. Novuncommon
  12. Decnot usually seen

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

0%1%2%3%Jan 1-7: 0% of 47145 checklistsJan 8-14: 0% of 35840 checklistsJan 15-21: 0% of 35423 checklistsJan 22-31: 0% of 49126 checklistsFeb 1-7: 0% of 36366 checklistsFeb 8-14: 0% of 42248 checklistsFeb 15-21: 0% of 55888 checklistsFeb 22-28: 0% of 42050 checklistsMar 1-7: 0% of 42709 checklistsMar 8-14: 0.1% of 43985 checklistsMar 15-21: 0.1% of 44547 checklistsMar 22-31: 0.4% of 66940 checklistsApr 1-7: 0.3% of 51147 checklistsApr 8-14: 0.4% of 54868 checklistsApr 15-21: 0.4% of 57252 checklistsApr 22-30: 0.5% of 81727 checklistsMay 1-7: 0.3% of 76472 checklistsMay 8-14: 0.2% of 79341 checklistsMay 15-21: 0.1% of 61724 checklistsMay 22-31: 0.1% of 70722 checklistsJun 1-7: 0.1% of 45652 checklistsJun 8-14: 0.1% of 41810 checklistsJun 15-21: 0% of 38973 checklistsJun 22-30: 0.1% of 44255 checklistsJul 1-7: 0.1% of 34822 checklistsJul 8-14: 0.1% of 31104 checklistsJul 15-21: 0.4% of 29262 checklistsJul 22-31: 1.1% of 41436 checklistsAug 1-7: 1.6% of 29189 checklistsAug 8-14: 1.2% of 28840 checklistsAug 15-21: 1.4% of 29948 checklistsAug 22-31: 1.7% of 48235 checklistsSep 1-7: 2.2% of 37175 checklistsSep 8-14: 1.7% of 36527 checklistsSep 15-21: 1.4% of 37261 checklistsSep 22-30: 1.7% of 43583 checklistsOct 1-7: 1.6% of 35352 checklistsOct 8-14: 1.2% of 35560 checklistsOct 15-21: 1.0% of 33119 checklistsOct 22-31: 1.1% of 44654 checklistsNov 1-7: 0.7% of 32965 checklistsNov 8-14: 0.3% 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% of 37465 checklistsDec 22-31: 0% 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. Lebanon CountyBest late August · 844 checklists that week, 33,727 in all9.3%
  2. Mercer CountyBest the second week of September · 332 checklists that week, 17,853 in all8.1%
  3. Philadelphia CountyBest the second week of August · 1241 checklists that week, 96,503 in all6.0%
  4. Somerset CountyBest early September · 191 checklists that week, 11,903 in all5.9%
  5. Northumberland CountyBest the second week of April · 276 checklists that week, 9,183 in all5.7%
  6. Indiana CountyBest late September · 352 checklists that week, 20,768 in all5.6%

Best spots

Share of checklists at the peak
  1. Shenango River Lake (Daley Run)Mercer County, best early September · 22 checklists that week, 220 in all70%
  2. South Hills ParkLebanon County, best late August · 39 checklists that week, 209 in all56%
  3. Newburg ParkNorthampton County, best late September · 31 checklists that week, 421 in all53%
  4. Codorus State ParkYork County, best early October · 39 checklists that week, 603 in all51%

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

Best time of day

In Pennsylvania, the Pectoral Sandpiper is most often listed on checklists started between 5 and 7 pm (0.7% of those checklists).

0%0.5%1%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: 0.5% of 92903 checklists7 am: 0.4% of 241233 checklists8 am: 0.4% of 271994 checklists9 am: 0.4% of 236842 checklists10 am: 0.4% of 199508 checklists11 am: 0.4% of 161893 checklists12 pm: 0.4% of 143945 checklists1 pm: 0.4% of 134352 checklists2 pm: 0.5% of 129692 checklists3 pm: 0.5% of 126132 checklists4 pm: 0.6% of 115055 checklists5 pm: 0.7% of 90719 checklists6 pm: 0.6% of 67534 checklists7 pm: 0.4% 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%0%0%0%
February0%0%0%0%
March0%0.1%0.1%0.4%
April0.3%0.4%0.4%0.5%
May0.3%0.2%0.1%0.1%
June0.1%0.1%0%0.1%
July0.1%0.1%0.4%1.1%
August1.6%1.2%1.4%1.7%
September2.2%1.7%1.4%1.7%
October1.6%1.2%1.0%1.1%
November0.7%0.3%0.1%0.1%
December0.1%0.1%0%0%

Neighboring states

  • Maryland: arrives mid July, 1 week earlier than Pennsylvania
  • District of Columbia: arrives late August, 4 weeks later than Pennsylvania
  • Delaware: arrives the second week of July, 2 weeks earlier than Pennsylvania
  • New Jersey: arrives late July, in the same week than Pennsylvania

Common questions

When do Pectoral Sandpipers arrive in Pennsylvania?
Pectoral Sandpipers arrive in Pennsylvania in late July, peak in early September (1.8% of checklists), and most are gone by early November.
When do Pectoral Sandpipers leave Pennsylvania?
Most Pectoral Sandpipers have left Pennsylvania by early November, when reports fall below half their usual rate.
When is the best time to see a Pectoral Sandpiper in Pennsylvania?
The Pectoral Sandpiper is reported most often in early September, on about 1.8% of Pennsylvania checklists.
Where in Pennsylvania are Pectoral Sandpipers seen most often?
By county, Lebanon County, Mercer County, and Philadelphia County have the highest peak reporting rates for the Pectoral Sandpiper (counties with at least 200 checklists).