Yellow-rumped Warblers reach Wyoming in the second week of April, are common by late April, peak in the second week of May (31% of checklists), and most are gone by the second week of October.
When to look
First arrivalsApr 8-14the second week of April
Common byApr 22-30late April
PeakMay 8-14the second week of May
Most gone byOct 8-14the second week of October
Best: the second week of May. First arrivals the second week of April; most are gone by the second week of October. Peak: on about 31% of Wyoming checklists.
Jannot usually seen
Febnot usually seen
Marnot usually seen
Aprcommon
Maypeak season
Junpeak season
Julcommon
Augcommon
Seppeak season
Octcommon
Novnot usually seen
Decnot usually seen
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 Wyoming 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.
Jenny LakeTeton County, best late May · 26 checklists that week, 300 in all80%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Wyoming, the Yellow-rumped Warbler is most often listed on checklists started between 6 and 8 am (17% 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
0.1%
0%
0%
0%
February
0.1%
0%
0%
0%
March
0%
0%
0%
0%
April
0.2%
1.2%
5.6%
17%
May
30%
32%
31%
27%
June
21%
19%
19%
21%
July
19%
20%
15%
10%
August
8.9%
9.9%
12%
16%
September
19%
22%
24%
24%
October
21%
16%
8.6%
2.2%
November
0.6%
0.3%
0.1%
0.2%
December
0.1%
0.1%
0%
0%
Neighboring states
Colorado: arrives mid March, 3 weeks earlier than Wyoming
Utah: arrives mid September, 21 weeks later than Wyoming
Montana: arrives mid April, 1 week later than Wyoming
Idaho: arrives the second week of September, 20 weeks later than Wyoming
Common questions
When do Yellow-rumped Warblers arrive in Wyoming?
Yellow-rumped Warblers reach Wyoming in the second week of April, are common by late April, peak in the second week of May (31% of checklists), and most are gone by the second week of October.
When do Yellow-rumped Warblers leave Wyoming?
Most Yellow-rumped Warblers have left Wyoming by the second week of October, when reports fall below half their usual rate. Stragglers are still reported until late October.
When is the best time to see a Yellow-rumped Warbler in Wyoming?
The Yellow-rumped Warbler is reported most often in the second week of May, on about 31% of Wyoming checklists.
Where in Wyoming are Yellow-rumped Warblers seen most often?
By county, Campbell County, Teton County, and Laramie County have the highest peak reporting rates for the Yellow-rumped Warbler (counties with at least 200 checklists).