Blackburnian Warblers arrive in Indiana in mid August, peak in the second week of September (7.4% of checklists), and most are gone by early October.
When to look
First arrivalsAug 15-21mid August
Common byAug 15-21mid August
PeakSep 8-14the second week of September
Most gone byOct 1-7early October
Best: the second week of September. First arrivals mid August; most are gone by early October. Peak: on about 7.4% of Indiana checklists.
Jannot usually seen
Febnot usually seen
Marnot usually seen
Apruncommon
Maypeak season
Jununcommon
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 Indiana 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 Indiana, the Blackburnian Warbler is most often listed on checklists started between 6 and 8 am (3.9% 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%
0.1%
0.9%
May
4.9%
8.2%
9.4%
2.3%
June
0.2%
0.1%
0.1%
0%
July
0%
0%
0%
0%
August
0.1%
0.2%
1.5%
5.0%
September
7.9%
7.1%
7.1%
4.6%
October
2.3%
0.7%
0.1%
0.1%
November
0%
0%
0%
0%
December
0%
0%
0%
0%
Neighboring states
Illinois: arrives late April, 15 weeks earlier than Indiana
Kentucky: arrives mid August, in the same week than Indiana
Ohio: arrives late April, 15 weeks earlier than Indiana
Michigan: arrives late April, 15 weeks earlier than Indiana
Common questions
When do Blackburnian Warblers arrive in Indiana?
Blackburnian Warblers arrive in Indiana in mid August, peak in the second week of September (7.4% of checklists), and most are gone by early October.
When do Blackburnian Warblers leave Indiana?
Most Blackburnian Warblers have left Indiana by early October, when reports fall below half their usual rate. Stragglers are still reported until the second week of October.
When is the best time to see a Blackburnian Warbler in Indiana?
The Blackburnian Warbler is reported most often in the second week of September, on about 7.4% of Indiana checklists.
Where in Indiana are Blackburnian Warblers seen most often?
By county, Spencer County, Vermillion County, and Shelby County have the highest peak reporting rates for the Blackburnian Warbler (counties with at least 200 checklists).