WhenToBird

Mimus polyglottos · Mimidae

When Do Northern Mockingbirds Arrive in Pennsylvania?

Adult Northern Mockingbird
Photo: Bill Keim, CC BY 4.0 via iNaturalist

The Northern Mockingbird is in Pennsylvania all year. It turns up on about 18% of checklists at its peak (mid October) and on 8.9% in its quietest week (early September).

When to look

PresentAll year
Peak weekOct 15-21mid October
Quietest weekSep 1-7early September

Best: mid October. Here all year. Peak: on about 18% of Pennsylvania checklists.

  1. Jancommon
  2. Febcommon
  3. Marcommon
  4. Aprcommon
  5. Maypeak season
  6. Junpeak season
  7. Julpeak season
  8. Augcommon
  9. Sepcommon
  10. Octpeak season
  11. Novpeak season
  12. Deccommon

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

0%5%10%15%20%Jan 1-7: 12% of 47145 checklistsJan 8-14: 12% of 35840 checklistsJan 15-21: 11% of 35423 checklistsJan 22-31: 11% of 49126 checklistsFeb 1-7: 11% of 36366 checklistsFeb 8-14: 11% of 42248 checklistsFeb 15-21: 9.5% of 55888 checklistsFeb 22-28: 11% of 42050 checklistsMar 1-7: 9.9% of 42709 checklistsMar 8-14: 11% of 43985 checklistsMar 15-21: 11% of 44547 checklistsMar 22-31: 12% of 66940 checklistsApr 1-7: 13% of 51147 checklistsApr 8-14: 14% of 54868 checklistsApr 15-21: 14% of 57252 checklistsApr 22-30: 13% of 81727 checklistsMay 1-7: 12% of 76472 checklistsMay 8-14: 12% of 79341 checklistsMay 15-21: 12% of 61724 checklistsMay 22-31: 14% of 70722 checklistsJun 1-7: 15% of 45652 checklistsJun 8-14: 14% of 41810 checklistsJun 15-21: 14% of 38973 checklistsJun 22-30: 14% of 44255 checklistsJul 1-7: 14% of 34822 checklistsJul 8-14: 15% of 31104 checklistsJul 15-21: 15% of 29262 checklistsJul 22-31: 13% of 41436 checklistsAug 1-7: 12% of 29189 checklistsAug 8-14: 11% of 28840 checklistsAug 15-21: 9.9% of 29948 checklistsAug 22-31: 9.2% of 48235 checklistsSep 1-7: 8.7% of 37175 checklistsSep 8-14: 8.8% of 36527 checklistsSep 15-21: 10% of 37261 checklistsSep 22-30: 12% of 43583 checklistsOct 1-7: 17% of 35352 checklistsOct 8-14: 18% of 35560 checklistsOct 15-21: 19% of 33119 checklistsOct 22-31: 18% of 44654 checklistsNov 1-7: 16% of 32965 checklistsNov 8-14: 14% of 31305 checklistsNov 15-21: 13% of 29471 checklistsNov 22-30: 13% of 38642 checklistsDec 1-7: 12% of 28779 checklistsDec 8-14: 13% of 29486 checklistsDec 15-21: 13% of 37465 checklistsDec 22-31: 14% 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.

Embed this map on your site

Where in Pennsylvania

Best counties

Share of checklists at the peak
  1. Adams CountyBest the second week of October · 414 checklists that week, 21,839 in all46%
  2. Fulton CountyBest the second week of October · 73 checklists that week, 7,004 in all41%
  3. Juniata CountyBest mid November · 105 checklists that week, 9,807 in all40%
  4. Franklin CountyBest the second week of July · 547 checklists that week, 36,756 in all39%
  5. Philadelphia CountyBest mid October · 1681 checklists that week, 96,503 in all34%
  6. Lancaster CountyBest the second week of October · 1571 checklists that week, 97,892 in all33%

Best spots

Share of checklists at the peak
  1. SpringfieldDelaware County, best late June · 31 checklists that week, 813 in all98%
  2. Janet Johnston Housenick & William D. Housenick Memorial ParkNorthampton County, best the second week of June · 51 checklists that week, 3,889 in all96%
  3. Dixon Meadow PreserveMontgomery County, best late June · 89 checklists that week, 6,425 in all94%
  4. Pennypack ParkPhiladelphia County, best late June · 24 checklists that week, 3,452 in all93%
  5. State Game Land 145Lebanon County, best early November · 37 checklists that week, 1,030 in all92%

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

Best time of day

In Pennsylvania, the Northern Mockingbird is most often listed on checklists started between 6 and 8 am (16% of those checklists).

0%5%10%15%20%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: 17% of 92903 checklists7 am: 15% of 241233 checklists8 am: 15% of 271994 checklists9 am: 14% of 236842 checklists10 am: 13% of 199508 checklists11 am: 12% of 161893 checklists12 pm: 12% of 143945 checklists1 pm: 11% of 134352 checklists2 pm: 11% of 129692 checklists3 pm: 10% of 126132 checklists4 pm: 9.7% of 115055 checklists5 pm: 10% of 90719 checklists6 pm: 10% of 67534 checklists7 pm: 9.0% 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
January12%12%11%11%
February11%11%9.5%11%
March9.9%11%11%12%
April13%14%14%13%
May12%12%12%14%
June15%14%14%14%
July14%15%15%13%
August12%11%9.9%9.2%
September8.7%8.8%10%12%
October17%18%19%18%
November16%14%13%13%
December12%13%13%14%

Neighboring states

Common questions

When do Northern Mockingbirds arrive in Pennsylvania?
The Northern Mockingbird is in Pennsylvania all year. It turns up on about 18% of checklists at its peak (mid October) and on 8.9% in its quietest week (early September).
When do Northern Mockingbirds leave Pennsylvania?
The Northern Mockingbird does not leave Pennsylvania: it is reported all year, from 8.9% of checklists in early September to 18% in mid October.
When is the best time to see a Northern Mockingbird in Pennsylvania?
The Northern Mockingbird is reported most often in mid October, on about 18% of Pennsylvania checklists.
Where in Pennsylvania are Northern Mockingbirds seen most often?
By county, Adams County, Fulton County, and Juniata County have the highest peak reporting rates for the Northern Mockingbird (counties with at least 200 checklists).