WhenToBird

6 swallow species in Pennsylvania

When Do Swallows Arrive in Pennsylvania?

Adult Barn Swallow
Photo: Diego González Dopico, CC BY 4.0 via iNaturalist

Barn Swallows, Tree Swallows, and Chimney Swifts are the swallows you are most likely to see in Pennsylvania. Barn Swallows reach Pennsylvania in early April, are common by mid April, peak in early August (31% of checklists), and most are gone by early September.

When to look

First arrivalsApr 1-7early April
Common byApr 15-21mid April
PeakAug 1-7early August
Most gone bySep 1-7early September

Best: early August. First arrivals early April; most are gone by early September. Peak: on about 31% of Pennsylvania checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Aprcommon
  5. Maypeak season
  6. Junpeak season
  7. Julpeak season
  8. Augpeak season
  9. Sepuncommon
  10. Octnot usually seen
  11. Novnot usually seen
  12. Decnot usually seen

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

Swallows in Pennsylvania, species by species

SpeciesFirst arrivalsCommon byPeakMost gone byPeak %
Barn SwallowApr 1-7Apr 15-21Aug 1-7Sep 1-731%
Tree SwallowMar 8-14Mar 22-31Apr 22-30Aug 15-2130%
Chimney SwiftApr 15-21Apr 22-30May 22-31Oct 1-722%
Purple MartinApr 8-14Apr 15-21Jul 22-31Aug 15-216.4%
Bank SwallowJul 1-7Jul 1-7Aug 8-14Sep 1-72.2%
Cliff SwallowApr 22-30Apr 22-30May 15-21Aug 22-311.7%
0%10%20%30%40%Barn SwallowTree SwallowChimney SwiftPurple MartinJanFebMarAprMayJunJulAugSepOctNovDec
  • Barn Swallow
  • Tree Swallow
  • Chimney Swift
  • Purple Martin
Share of complete checklists reporting each species, by week (4 per month). Gaps: fewer than 10 checklists that week.

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.

Where in Pennsylvania

Best counties for Barn Swallow

Share of checklists at the peak
  1. Fulton CountyBest early August · 93 checklists that week, 7,004 in all56%
  2. Franklin CountyBest the second week of August · 558 checklists that week, 36,756 in all53%
  3. Philadelphia CountyBest early August · 1366 checklists that week, 96,503 in all52%
  4. Mifflin CountyBest early August · 63 checklists that week, 6,998 in all50%
  5. Lancaster CountyBest early August · 1600 checklists that week, 97,892 in all47%
  6. Lehigh CountyBest mid July · 570 checklists that week, 41,072 in all44%

All swallows in Pennsylvania

6 species are reported regularly: 6 are summer visitors.

#SpeciesPatternThrough the yearFirst arrivalsPeakPeak %
1Barn SwallowSummer visitorApr 1-7Aug 1-731%
2Tree SwallowSummer visitorMar 8-14Apr 22-3030%
3Northern Rough-winged SwallowSummer visitorMar 15-21Apr 22-3015%
4Purple MartinSummer visitorApr 8-14Jul 22-316.4%
5Bank SwallowSummer visitorJul 1-7Aug 8-142.2%
6Cliff SwallowSummer visitorApr 22-30May 15-211.7%

Common questions

When do swallows arrive in Pennsylvania?
Barn Swallows reach Pennsylvania in early April, are common by mid April, peak in early August (31% of checklists), and most are gone by early September.
When do swallows leave Pennsylvania?
Most Barn Swallows have left Pennsylvania by early September, when reports fall below half their usual rate. Stragglers are still reported until the second week of September.
When is the best time to see swallows in Pennsylvania?
The Barn Swallow is reported most often in early August, on about 31% of Pennsylvania checklists.
Which swallows are in Pennsylvania?
Barn Swallow, Tree Swallow, Chimney Swift, Purple Martin, Bank Swallow, and Cliff Swallow are reported regularly; the Barn Swallow is the most common.