Blackburnian Warblers mostly pass through North Dakota: they arrive in the second week of August, peak in late August (2.2% of checklists), and most are gone by the second week of September.
When to look
First arrivalsAug 8-14the second week of August
Common byAug 8-14the second week of August
PeakAug 22-31late August
Most gone bySep 8-14the second week of September
Best: late August. First arrivals the second week of August; most are gone by the second week of September. Peak: on about 2.2% of North Dakota checklists.
Jannot usually seen
Febnot usually seen
Marnot usually seen
Aprnot usually seen
Maypeak season
Juncommon
Julnot usually seen
Augpeak season
Seppeak season
Octnot usually seen
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 North Dakota 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.
Wells CountyBest mid August · 11 checklists that week, 416 in all20%
Renville CountyBest late August · 10 checklists that week, 415 in all11%
Ramsey CountyBest early May · 12 checklists that week, 722 in all9.6%
Sheridan CountyBest mid August · 18 checklists that week, 620 in all8.3%
Nelson CountyBest early September · 24 checklists that week, 470 in all7.0%
Benson CountyBest mid August · 16 checklists that week, 986 in all6.8%
Best spots
Share of checklists at the peak
Riverside ParkGrand Forks County, best late May · 21 checklists that week, 102 in all30%
Oak Grove ParkCass County, best late May · 53 checklists that week, 387 in all18%
Treefoil ParkCass County, best late May · 121 checklists that week, 1,125 in all13%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In North Dakota, the Blackburnian Warbler is most often listed on checklists started between 6 and 8 am (0.8% 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%
0.5%
3.0%
2.1%
June
0.1%
0.1%
0.1%
0%
July
0%
0%
0%
0%
August
0%
0.2%
2.2%
2.9%
September
1.2%
1.0%
0.2%
0.1%
October
0.1%
0.1%
0%
0%
November
0%
0%
0%
0%
December
0%
0%
0%
0%
Neighboring states
Minnesota: arrives early May, 13 weeks earlier than North Dakota
Nebraska: arrives the second week of May, 12 weeks earlier than North Dakota
Iowa: arrives mid August, 1 week later than North Dakota
Wisconsin: arrives early May, 13 weeks earlier than North Dakota
Common questions
When do Blackburnian Warblers arrive in North Dakota?
Blackburnian Warblers mostly pass through North Dakota: they arrive in the second week of August, peak in late August (2.2% of checklists), and most are gone by the second week of September.
When do Blackburnian Warblers leave North Dakota?
Most Blackburnian Warblers have left North Dakota by the second week of September, when reports fall below half their usual rate.
When is the best time to see a Blackburnian Warbler in North Dakota?
The Blackburnian Warbler is reported most often in late August, on about 2.2% of North Dakota checklists.
Where in North Dakota are Blackburnian Warblers seen most often?
By county, Wells County, Renville County, and Ramsey County have the highest peak reporting rates for the Blackburnian Warbler (counties with at least 200 checklists).