WhenToBird

Setophaga caerulescens · Parulidae

Black-throated Blue Warbler: When and Where to See It

Adult male Black-throated Blue Warbler
Photo: Dan Vickers, CC BY 4.0 via iNaturalist

The Black-throated Blue Warbler reaches North Carolina first, around the second week of April, and Wisconsin last, around late April.

JanFebMarAprMayJunJulAugSepOctNovDec
today
Second week of November

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.

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0%2%4%6%8%Jan 1-7: 0.1% of 1114036 checklistsJan 8-14: 0.1% of 824708 checklistsJan 15-21: 0.1% of 825978 checklistsJan 22-31: 0.1% of 1105853 checklistsFeb 1-7: 0.1% of 779772 checklistsFeb 8-14: 0.1% of 864504 checklistsFeb 15-21: 0.1% of 1127933 checklistsFeb 22-28: 0.1% of 840124 checklistsMar 1-7: 0.1% of 839610 checklistsMar 8-14: 0.1% of 870138 checklistsMar 15-21: 0.1% of 898456 checklistsMar 22-31: 0.1% of 1335637 checklistsApr 1-7: 0.1% of 1030617 checklistsApr 8-14: 0.2% of 1124024 checklistsApr 15-21: 0.5% of 1194575 checklistsApr 22-30: 1.6% of 1675723 checklistsMay 1-7: 4.9% of 1449080 checklistsMay 8-14: 6.1% of 1538353 checklistsMay 15-21: 4.6% of 1219898 checklistsMay 22-31: 1.6% of 1452282 checklistsJun 1-7: 1.2% of 900636 checklistsJun 8-14: 1.2% of 829907 checklistsJun 15-21: 1.2% of 773255 checklistsJun 22-30: 1.1% of 916255 checklistsJul 1-7: 1.0% of 717733 checklistsJul 8-14: 0.8% of 658223 checklistsJul 15-21: 0.7% of 638752 checklistsJul 22-31: 0.4% of 895727 checklistsAug 1-7: 0.3% of 655651 checklistsAug 8-14: 0.2% of 650038 checklistsAug 15-21: 0.3% of 654639 checklistsAug 22-31: 0.7% of 974928 checklistsSep 1-7: 1.4% of 765914 checklistsSep 8-14: 1.9% of 738674 checklistsSep 15-21: 2.4% of 750433 checklistsSep 22-30: 2.5% of 944196 checklistsOct 1-7: 2.8% of 760106 checklistsOct 8-14: 2.3% of 793131 checklistsOct 15-21: 1.5% of 728727 checklistsOct 22-31: 0.7% of 959954 checklistsNov 1-7: 0.3% of 709464 checklistsNov 8-14: 0.2% of 693424 checklistsNov 15-21: 0.1% of 653952 checklistsNov 22-30: 0.1% of 871137 checklistsDec 1-7: 0.1% of 627591 checklistsDec 8-14: 0.1% of 642427 checklistsDec 15-21: 0.1% of 775638 checklistsDec 22-31: 0.1% of 1132751 checklistsJanFebMarAprMayJunJulAugSepOctNovDec
Share of complete checklists reporting it, by week (4 per month). Grey bars: fewer than 10 checklists, not counted.

Pooled across every state in the data, so it leans toward states with the most birders.

States, in order of first arrivals

StatePatternFirst arrivalsPeakMost gone byPeak %
North CarolinaSummer visitorApr 8-14May 1-7Oct 22-3111%
South CarolinaPasses throughApr 8-14May 1-7May 22-315.3%
GeorgiaPasses throughApr 8-14May 1-7Jul 1-74.5%
District of ColumbiaPasses throughApr 15-21May 8-14May 22-3123%
MarylandPasses throughApr 15-21May 8-14Jun 1-711%
New JerseySummer visitorApr 15-21May 8-14Jul 15-2110%
VirginiaPasses throughApr 15-21May 8-14Jun 22-3011%
TennesseeSummer visitorApr 15-21May 1-7Jul 1-71.4%
New HampshireSummer visitorApr 22-30May 15-21Jul 15-2113%
New YorkSummer visitorApr 22-30May 8-14Jul 15-2114%
VermontSummer visitorApr 22-30May 22-31Sep 15-2115%
MaineSummer visitorApr 22-30May 15-21Jul 15-2111%
OhioPasses throughApr 22-30May 8-14Jun 1-712%
ConnecticutPasses throughApr 22-30May 8-14Jul 8-149.2%
DelawarePasses throughApr 22-30May 8-14May 15-218.1%
MassachusettsPasses throughApr 22-30May 8-14May 22-319.8%
PennsylvaniaSummer visitorApr 22-30May 8-14Jul 8-1410%
MichiganSummer visitorApr 22-30May 8-14Jun 22-305.4%
Rhode IslandPasses throughApr 22-30May 8-14Jun 8-145.5%
West VirginiaSummer visitorApr 22-30May 8-14Oct 8-146.3%
IndianaSummer visitorApr 22-30May 8-14May 22-312.2%
KentuckyPasses throughApr 22-30May 8-14May 15-211.1%
WisconsinSummer visitorApr 22-30May 8-14Jul 8-141.9%
IllinoisSummer visitorAug 22-31Sep 15-21Oct 8-143.4%
FloridaWinter visitorAug 15-21Oct 8-14Jan 8-1411%

Winter visitor in: Florida

Summer visitor in: Illinois