Mourning Warblers mostly pass through Oklahoma: they arrive in late August, peak in mid September (1.5% of checklists), and most are gone by early October.
When to look
First arrivalsAug 22-31late August
Common byAug 22-31late August
PeakSep 15-21mid September
Most gone byOct 1-7early October
Best: mid September. First arrivals late August; most are gone by early October. Peak: on about 1.5% of Oklahoma checklists.
Jannot usually seen
Febnot usually seen
Marnot usually seen
Aprnot usually seen
Maycommon
Junrare
Julnot usually seen
Augcommon
Seppeak season
Octuncommon
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 Oklahoma 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.
Washington CountyBest late August · 18 checklists that week, 2,263 in all7.7%
Tulsa CountyBest mid September · 552 checklists that week, 33,355 in all5.6%
Oklahoma CountyBest the second week of September · 645 checklists that week, 38,139 in all2.2%
Delaware CountyBest the second week of May · 74 checklists that week, 1,727 in all1.5%
Osage CountyBest mid May · 64 checklists that week, 3,750 in all1.2%
Cleveland CountyBest mid May · 485 checklists that week, 21,516 in all1.0%
Best spots
Share of checklists at the peak
TulsaTulsa County, best mid September · 52 checklists that week, 1,288 in all43%
Myriad GardensOklahoma County, best the second week of September · 71 checklists that week, 911 in all27%
Recreation LakeTulsa County, best early September · 70 checklists that week, 3,060 in all12%
Woodward ParkTulsa County, best mid May · 34 checklists that week, 458 in all7.1%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Oklahoma, the Mourning Warbler is most often listed on checklists started between 6 and 8 am (0.4% 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%
0%
0%
0%
February
0%
0%
0%
0%
March
0%
0%
0%
0%
April
0%
0%
0%
0%
May
0.2%
0.7%
1.3%
0.4%
June
0.1%
0%
0%
0%
July
0%
0%
0%
0%
August
0%
0%
0%
0.8%
September
1.2%
2.1%
1.3%
1.2%
October
0.2%
0.1%
0.1%
0%
November
0%
0%
0%
0%
December
0%
0%
0%
0%
Neighboring states
Kansas: arrives the second week of May, 14 weeks earlier than Oklahoma
Missouri: arrives the second week of May, 14 weeks earlier than Oklahoma
Nebraska: arrives the second week of May, 14 weeks earlier than Oklahoma
Texas: arrives late August, in the same week than Oklahoma
Common questions
When do Mourning Warblers arrive in Oklahoma?
Mourning Warblers mostly pass through Oklahoma: they arrive in late August, peak in mid September (1.5% of checklists), and most are gone by early October.
When do Mourning Warblers leave Oklahoma?
Most Mourning Warblers have left Oklahoma by early October, when reports fall below half their usual rate.
When is the best time to see a Mourning Warbler in Oklahoma?
The Mourning Warbler is reported most often in mid September, on about 1.5% of Oklahoma checklists.
Where in Oklahoma are Mourning Warblers seen most often?
By county, Washington County, Tulsa County, and Oklahoma County have the highest peak reporting rates for the Mourning Warbler (counties with at least 200 checklists).