Yellow-rumped Warblers are winter birds in Iowa: they arrive in early September, peak in the second week of October (42% of checklists), and most are gone by late December.
When to look
First arrivalsSep 1-7early September
Common bySep 1-7early September
PeakOct 8-14the second week of October
Most gone byDec 22-31late December
Best: the second week of October. First arrivals early September; most are gone by late December. Peak: on about 42% of Iowa checklists.
Jannot usually seen
Febnot usually seen
Marrare
Aprpeak season
Maycommon
Junnot usually seen
Julnot usually seen
Augnot usually seen
Sepcommon
Octpeak season
Novuncommon
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 Iowa 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 Iowa, the Yellow-rumped Warbler is most often listed on checklists started between 6 and 8 am (12% 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
0.7%
0.7%
0.4%
0.7%
February
0.7%
0.6%
0.1%
0.3%
March
0.3%
0.6%
0.4%
0.7%
April
3.9%
12%
23%
32%
May
37%
23%
6.5%
0.2%
June
0%
0%
0%
0%
July
0%
0%
0%
0%
August
0%
0.1%
0%
0.1%
September
0.4%
2.7%
7.5%
31%
October
45%
45%
36%
20%
November
8.7%
3.0%
1.7%
1.6%
December
1.1%
2.0%
2.3%
0.9%
Neighboring states
Missouri: arrives mid September, 2 weeks later than Iowa
Wisconsin: arrives late March, 21 weeks earlier than Iowa
Minnesota: arrives early April, 20 weeks earlier than Iowa
Illinois: arrives late August, 1 week earlier than Iowa
Common questions
When do Yellow-rumped Warblers arrive in Iowa?
Yellow-rumped Warblers are winter birds in Iowa: they arrive in early September, peak in the second week of October (42% of checklists), and most are gone by late December.
When do Yellow-rumped Warblers leave Iowa?
Most Yellow-rumped Warblers have left Iowa by late December, when reports fall below half their usual rate.
When is the best time to see a Yellow-rumped Warbler in Iowa?
The Yellow-rumped Warbler is reported most often in the second week of October, on about 42% of Iowa checklists.
Where in Iowa are Yellow-rumped Warblers seen most often?
By county, Union County, Clarke County, and Mitchell County have the highest peak reporting rates for the Yellow-rumped Warbler (counties with at least 200 checklists).