WhenToBird

2 grosbeak species in Pennsylvania

When Do Grosbeaks Arrive in Pennsylvania?

Adult male Rose-breasted Grosbeak
Photo: Nancy Overholtz, CC BY-SA 4.0 via iNaturalist

Rose-breasted Grosbeaks reach Pennsylvania in mid April, are common by late April, peak in the second week of May (17% of checklists), and most are gone by early October. They are by far the most reported grosbeaks in Pennsylvania.

When to look

First arrivalsApr 15-21mid April
Common byApr 22-30late April
PeakMay 8-14the second week of May
Most gone byOct 1-7early October

Best: the second week of May. First arrivals mid April; most are gone by early October. Peak: on about 17% of Pennsylvania checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Aprcommon
  5. Maypeak season
  6. Juncommon
  7. Juluncommon
  8. Auguncommon
  9. Sepcommon
  10. Octuncommon
  11. Novnot usually seen
  12. Decnot usually seen

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

Grosbeaks in Pennsylvania, species by species

SpeciesFirst arrivalsCommon byPeakMost gone byPeak %
Rose-breasted GrosbeakApr 15-21Apr 22-30May 8-14Oct 1-717%
Blue GrosbeakMay 15-21May 15-21Aug 8-14Sep 8-141.5%
0%5%10%15%20%Rose-breasted GrosbeakBlue GrosbeakJanFebMarAprMayJunJulAugSepOctNovDec
  • Rose-breasted Grosbeak
  • Blue Grosbeak
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 Rose-breasted Grosbeak

Share of checklists at the peak
  1. Mercer CountyBest the second week of May · 690 checklists that week, 17,853 in all46%
  2. Warren CountyBest the second week of May · 229 checklists that week, 5,449 in all46%
  3. Jefferson CountyBest the second week of May · 242 checklists that week, 5,956 in all41%
  4. Forest CountyBest the second week of May · 383 checklists that week, 5,388 in all40%
  5. Clarion CountyBest the second week of May · 295 checklists that week, 9,153 in all39%
  6. Susquehanna CountyBest the second week of May · 710 checklists that week, 22,573 in all39%

Common questions

When do grosbeaks arrive in Pennsylvania?
Rose-breasted Grosbeaks reach Pennsylvania in mid April, are common by late April, peak in the second week of May (17% of checklists), and most are gone by early October. They are by far the most reported grosbeaks in Pennsylvania.
When do grosbeaks leave Pennsylvania?
Most Rose-breasted Grosbeaks have left Pennsylvania by early October, when reports fall below half their usual rate. Stragglers are still reported until the second week of October.
When is the best time to see grosbeaks in Pennsylvania?
The Rose-breasted Grosbeak is reported most often in the second week of May, on about 17% of Pennsylvania checklists.
Which grosbeaks are in Pennsylvania?
Rose-breasted Grosbeak and Blue Grosbeak are reported regularly; the Rose-breasted Grosbeak is the most common.