WhenToBird

Setophaga caerulescens · Parulidae

When Do Black-throated Blue Warblers Arrive in Vermont?

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

Black-throated Blue Warblers reach Vermont in late April, are common by early May, peak in late May (15% of checklists), and most are gone by mid September.

When to look

First arrivalsApr 22-30late April
Common byMay 1-7early May
PeakMay 22-31late May
Most gone bySep 15-21mid September

Best: late May. First arrivals late April; most are gone by mid September. Peak: on about 15% of Vermont checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Aprrare
  5. Maypeak season
  6. Junpeak season
  7. Julpeak season
  8. Auguncommon
  9. Sepuncommon
  10. Octrare
  11. Novnot usually seen
  12. Decnot usually seen

Darker months: more checklists report it. Outlined: peak month.

0%5%10%15%20%Jan 1-7: 0% of 12234 checklistsJan 8-14: 0% of 8293 checklistsJan 15-21: 0% of 7885 checklistsJan 22-31: 0% of 10534 checklistsFeb 1-7: 0% of 7212 checklistsFeb 8-14: 0% of 8144 checklistsFeb 15-21: 0% of 10480 checklistsFeb 22-28: 0% of 7932 checklistsMar 1-7: 0% of 8192 checklistsMar 8-14: 0% of 9383 checklistsMar 15-21: 0% of 10620 checklistsMar 22-31: 0% of 16257 checklistsApr 1-7: 0% of 12568 checklistsApr 8-14: 0% of 14677 checklistsApr 15-21: 0.1% of 14106 checklistsApr 22-30: 0.3% of 19617 checklistsMay 1-7: 4.9% of 18143 checklistsMay 8-14: 12% of 19626 checklistsMay 15-21: 16% of 17779 checklistsMay 22-31: 15% of 20310 checklistsJun 1-7: 13% of 11493 checklistsJun 8-14: 12% of 10215 checklistsJun 15-21: 13% of 9951 checklistsJun 22-30: 12% of 11050 checklistsJul 1-7: 11% of 8690 checklistsJul 8-14: 9.9% of 7679 checklistsJul 15-21: 9.0% of 7687 checklistsJul 22-31: 5.4% of 10712 checklistsAug 1-7: 3.2% of 7703 checklistsAug 8-14: 3.0% of 7743 checklistsAug 15-21: 2.7% of 8314 checklistsAug 22-31: 3.5% of 12428 checklistsSep 1-7: 4.8% of 9526 checklistsSep 8-14: 4.9% of 8493 checklistsSep 15-21: 4.2% of 8283 checklistsSep 22-30: 2.8% of 10352 checklistsOct 1-7: 1.1% of 8802 checklistsOct 8-14: 0.2% of 9088 checklistsOct 15-21: 0.1% of 7739 checklistsOct 22-31: 0.1% of 10907 checklistsNov 1-7: 0% of 7868 checklistsNov 8-14: 0.1% of 7223 checklistsNov 15-21: 0% of 7224 checklistsNov 22-30: 0% of 8375 checklistsDec 1-7: 0% of 6580 checklistsDec 8-14: 0% of 6800 checklistsDec 15-21: 0% of 8334 checklistsDec 22-31: 0% of 10579 checklistsJanFebMarAprMayJunJulAugSepOctNovDec
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 Vermont 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
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.

Embed this map on your site

Where in Vermont

Best counties

Share of checklists at the peak
  1. Essex CountyBest late May · 603 checklists that week, 9,416 in all50%
  2. Caledonia CountyBest late May · 449 checklists that week, 10,534 in all26%
  3. Orleans CountyBest early June · 305 checklists that week, 11,785 in all22%
  4. Washington CountyBest late May · 1445 checklists that week, 37,036 in all22%
  5. Lamoille CountyBest late May · 770 checklists that week, 16,426 in all22%
  6. Orange CountyBest late May · 981 checklists that week, 16,964 in all19%

Best spots

Share of checklists at the peak
  1. Camels Hump State ForestChittenden County, best late May · 21 checklists that week, 299 in all96%
  2. Hinesburg Town ForestChittenden County, best late May · 94 checklists that week, 482 in all94%
  3. Woodford State ParkBennington County, best late May · 24 checklists that week, 127 in all89%
  4. Marsh-Billings-Rockefeller National Historical ParkWindsor County, best late May · 34 checklists that week, 401 in all85%
  5. Laplatte Headwaters Town ForestChittenden County, best late May · 30 checklists that week, 722 in all80%
  6. Enosburg Town ForestFranklin County, best late May · 22 checklists that week, 136 in all80%

Busy spots report more of everything; compare the checklist counts before you drive anywhere.

Best time of day

In Vermont, the Black-throated Blue Warbler is most often listed on checklists started between 5 and 7 am (8.3% of those checklists).

0%5%10%12 am: too few checklists (384) to judge1 am: too few checklists (418) to judge2 am: too few checklists (568) to judge3 am: too few checklists (1183) to judge4 am: too few checklists (3460) to judge5 am: 9.8% of 10340 checklists6 am: 7.7% of 30951 checklists7 am: 5.6% of 64150 checklists8 am: 4.8% of 70252 checklists9 am: 4.5% of 55280 checklists10 am: 3.8% of 47111 checklists11 am: 3.1% of 37615 checklists12 pm: 2.7% of 32195 checklists1 pm: 2.4% of 30185 checklists2 pm: 2.2% of 29679 checklists3 pm: 1.9% of 26483 checklists4 pm: 2.4% of 20110 checklists5 pm: 2.7% of 15993 checklists6 pm: 2.1% of 12110 checklists7 pm: too few checklists (8203) to judge8 pm: too few checklists (4425) to judge9 pm: too few checklists (1829) to judge10 pm: too few checklists (597) to judge11 pm: too few checklists (309) to judge12a3a6a9a12p3p6p9p
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
MonthDays 1-78-1415-2122-end
January0%0%0%0%
February0%0%0%0%
March0%0%0%0%
April0%0%0.1%0.3%
May4.9%12%16%15%
June13%12%13%12%
July11%9.9%9.0%5.4%
August3.2%3.0%2.7%3.5%
September4.8%4.9%4.2%2.8%
October1.1%0.2%0.1%0.1%
November0%0.1%0%0%
December0%0%0%0%

Neighboring states

  • New Hampshire: arrives late April, in the same week than Vermont
  • Massachusetts: arrives late April, in the same week than Vermont
  • Connecticut: arrives late April, in the same week than Vermont
  • Rhode Island: arrives late April, in the same week than Vermont

Common questions

When do Black-throated Blue Warblers arrive in Vermont?
Black-throated Blue Warblers reach Vermont in late April, are common by early May, peak in late May (15% of checklists), and most are gone by mid September.
When do Black-throated Blue Warblers leave Vermont?
Most Black-throated Blue Warblers have left Vermont by mid September, when reports fall below half their usual rate. Stragglers are still reported until early October.
When is the best time to see a Black-throated Blue Warbler in Vermont?
The Black-throated Blue Warbler is reported most often in late May, on about 15% of Vermont checklists.
Where in Vermont are Black-throated Blue Warblers seen most often?
By county, Essex County, Caledonia County, and Orleans County have the highest peak reporting rates for the Black-throated Blue Warbler (counties with at least 200 checklists).