WhenToBird

Setophaga fusca · Parulidae

When Do Blackburnian Warblers Arrive in Connecticut?

Adult male Blackburnian Warbler
Photo: Matt Felperin, CC BY 4.0 via iNaturalist

Blackburnian Warblers arrive in Connecticut in early May, peak in mid May (4.2% of checklists), and most are gone by the second week of July.

When to look

First arrivalsMay 1-7early May
Common byMay 1-7early May
PeakMay 15-21mid May
Most gone byJul 8-14the second week of July

Best: mid May. First arrivals early May; most are gone by the second week of July. Peak: on about 4.2% of Connecticut checklists.

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

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

0%2%4%6%Jan 1-7: 0% of 18950 checklistsJan 8-14: 0% of 13676 checklistsJan 15-21: 0% of 13377 checklistsJan 22-31: 0% of 17004 checklistsFeb 1-7: 0% of 10218 checklistsFeb 8-14: 0% of 11568 checklistsFeb 15-21: 0% of 15916 checklistsFeb 22-28: 0% of 11413 checklistsMar 1-7: 0% of 10754 checklistsMar 8-14: 0% of 12051 checklistsMar 15-21: 0% of 12616 checklistsMar 22-31: 0% of 17801 checklistsApr 1-7: 0% of 13186 checklistsApr 8-14: 0% of 14428 checklistsApr 15-21: 0% of 14738 checklistsApr 22-30: 0.2% of 21753 checklistsMay 1-7: 2.1% of 22494 checklistsMay 8-14: 4.0% of 23363 checklistsMay 15-21: 5.4% of 20219 checklistsMay 22-31: 3.3% of 20778 checklistsJun 1-7: 2.6% of 12234 checklistsJun 8-14: 2.5% of 12491 checklistsJun 15-21: 3.0% of 10856 checklistsJun 22-30: 3.0% of 11964 checklistsJul 1-7: 1.6% of 9437 checklistsJul 8-14: 1.6% of 8599 checklistsJul 15-21: 1.0% of 8252 checklistsJul 22-31: 0.5% of 11329 checklistsAug 1-7: 0.3% of 8116 checklistsAug 8-14: 0.4% of 8051 checklistsAug 15-21: 0.4% of 8502 checklistsAug 22-31: 1.0% of 13673 checklistsSep 1-7: 1.0% of 9873 checklistsSep 8-14: 1.2% of 9735 checklistsSep 15-21: 1.1% of 10120 checklistsSep 22-30: 0.9% of 12543 checklistsOct 1-7: 0.3% of 10735 checklistsOct 8-14: 0.1% of 10869 checklistsOct 15-21: 0% of 10436 checklistsOct 22-31: 0.1% of 13808 checklistsNov 1-7: 0% of 10507 checklistsNov 8-14: 0% of 9827 checklistsNov 15-21: 0% of 9904 checklistsNov 22-30: 0% of 13396 checklistsDec 1-7: 0% of 8974 checklistsDec 8-14: 0% of 9468 checklistsDec 15-21: 0% of 11614 checklistsDec 22-31: 0% of 16616 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 Connecticut 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.

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Where in Connecticut

Best counties

Share of checklists at the peak
  1. Litchfield CountyBest mid June · 1742 checklists that week, 69,766 in all14%
  2. Windham CountyBest mid May · 1029 checklists that week, 19,034 in all5.4%
  3. New Haven CountyBest the second week of May · 5629 checklists that week, 139,721 in all4.3%
  4. Hartford CountyBest mid May · 3461 checklists that week, 105,735 in all3.6%
  5. Fairfield CountyBest the second week of May · 4844 checklists that week, 139,848 in all3.6%
  6. Tolland CountyBest mid May · 1241 checklists that week, 39,004 in all2.6%

Best spots

Share of checklists at the peak
  1. Yale ForestWindham County, best mid May · 40 checklists that week, 327 in all57%
  2. Appalachian National Scenic TrailLitchfield County, best the second week of May · 73 checklists that week, 308 in all20%
  3. Mclean Game RefugeHartford County, best late May · 21 checklists that week, 353 in all19%
  4. Penwood State ParkHartford County, best the second week of May · 26 checklists that week, 192 in all19%
  5. Bluff PointNew London County, best early September · 61 checklists that week, 770 in all18%

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

Best time of day

In Connecticut, the Blackburnian Warbler is most often listed on checklists started between 6 and 8 am (1.6% of those checklists).

0%1%2%3%12 am: too few checklists (325) to judge1 am: too few checklists (367) to judge2 am: too few checklists (488) to judge3 am: too few checklists (792) to judge4 am: too few checklists (2722) to judge5 am: too few checklists (9489) to judge6 am: 2.1% of 33657 checklists7 am: 1.3% of 62964 checklists8 am: 1.0% of 70645 checklists9 am: 0.8% of 64870 checklists10 am: 0.7% of 58827 checklists11 am: 0.7% of 51689 checklists12 pm: 0.7% of 45288 checklists1 pm: 0.7% of 44765 checklists2 pm: 0.7% of 44173 checklists3 pm: 0.7% of 41979 checklists4 pm: 0.9% of 33219 checklists5 pm: 0.9% of 24828 checklists6 pm: 0.7% of 15856 checklists7 pm: too few checklists (8126) to judge8 pm: too few checklists (1994) to judge9 pm: too few checklists (533) to judge10 pm: too few checklists (349) to judge11 pm: too few checklists (286) 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%0.2%
May2.1%4.0%5.4%3.3%
June2.6%2.5%3.0%3.0%
July1.6%1.6%1.0%0.5%
August0.3%0.4%0.4%1.0%
September1.0%1.2%1.1%0.9%
October0.3%0.1%0%0.1%
November0%0%0%0%
December0%0%0%0%

Neighboring states

  • Rhode Island: arrives early May, in the same week than Connecticut
  • Massachusetts: arrives early May, in the same week than Connecticut
  • New Jersey: arrives late April, 1 week earlier than Connecticut
  • New York: arrives late April, 1 week earlier than Connecticut

Common questions

When do Blackburnian Warblers arrive in Connecticut?
Blackburnian Warblers arrive in Connecticut in early May, peak in mid May (4.2% of checklists), and most are gone by the second week of July.
When do Blackburnian Warblers leave Connecticut?
Most Blackburnian Warblers have left Connecticut by the second week of July, when reports fall below half their usual rate.
When is the best time to see a Blackburnian Warbler in Connecticut?
The Blackburnian Warbler is reported most often in mid May, on about 4.2% of Connecticut checklists.
Where in Connecticut are Blackburnian Warblers seen most often?
By county, Litchfield County, Windham County, and New Haven County have the highest peak reporting rates for the Blackburnian Warbler (counties with at least 200 checklists).