Yellow-rumped Warblers are winter birds in Pennsylvania: the first arrive in early September, they are common by the second week of September, peak in mid October (25% of checklists), and most are gone by late May.
When to look
First arrivalsSep 1-7early September
Common bySep 8-14the second week of September
PeakOct 15-21mid October
Most gone byMay 22-31late May
Best: mid October. First arrivals early September; most are gone by late May. Peak: on about 25% of Pennsylvania checklists.
Janrare
Febrare
Marrare
Aprpeak season
Maypeak season
Junnot usually seen
Julnot usually seen
Augnot usually seen
Sepuncommon
Octpeak season
Novcommon
Decrare
Darker months: more checklists report it. Outlined: peak month.
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
0%few checklistsno data
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.
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Pennsylvania, the Yellow-rumped Warbler is most often listed on checklists started between 6 and 8 am (9.7% of those checklists).
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
Month
Days 1-7
8-14
15-21
22-end
January
2.2%
2.3%
2.1%
2.0%
February
2.0%
1.6%
1.4%
1.9%
March
1.8%
1.8%
2.1%
2.7%
April
3.9%
7.6%
14%
23%
May
27%
20%
7.2%
1.3%
June
0.5%
0.5%
0.5%
0.6%
July
0.6%
0.6%
0.4%
0.3%
August
0.2%
0.2%
0.3%
0.6%
September
1.1%
1.7%
3.3%
7.8%
October
19%
27%
29%
21%
November
12%
6.6%
4.7%
3.7%
December
3.1%
2.7%
2.6%
2.5%
Neighboring states
Maryland: arrives mid September, 2 weeks later than Pennsylvania
Delaware: arrives mid September, 2 weeks later than Pennsylvania
New Jersey: arrives the second week of September, 1 week later than Pennsylvania
Common questions
When do Yellow-rumped Warblers arrive in Pennsylvania?
Yellow-rumped Warblers are winter birds in Pennsylvania: the first arrive in early September, they are common by the second week of September, peak in mid October (25% of checklists), and most are gone by late May.
When do Yellow-rumped Warblers leave Pennsylvania?
Most Yellow-rumped Warblers have left Pennsylvania by late May, when reports fall below half their usual rate.
When is the best time to see a Yellow-rumped Warbler in Pennsylvania?
The Yellow-rumped Warbler is reported most often in mid October, on about 25% of Pennsylvania checklists.
Where in Pennsylvania are Yellow-rumped Warblers seen most often?
By county, Philadelphia County, Bucks County, and Wayne County have the highest peak reporting rates for the Yellow-rumped Warbler (counties with at least 200 checklists).