WhenToBird

5 swallow species in Connecticut

When Do Swallows Arrive in Connecticut?

Adult Tree Swallow
Photo: Carter Dorscht, CC0 1.0 via iNaturalist

Tree Swallows, Barn Swallows, and Chimney Swifts are the swallows you are most likely to see in Connecticut. Tree Swallows reach Connecticut in mid March, are common by early April, peak in late May (33% of checklists), and most are gone by early September.

When to look

First arrivalsMar 15-21mid March
Common byApr 1-7early April
PeakMay 22-31late May
Most gone bySep 1-7early September

Best: late May. First arrivals mid March; most are gone by early September. Peak: on about 33% of Connecticut checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Maruncommon
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julcommon
  8. Augcommon
  9. Sepcommon
  10. Octuncommon
  11. Novrare
  12. Decnot usually seen

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

Swallows in Connecticut, species by species

SpeciesFirst arrivalsCommon byPeakMost gone byPeak %
Tree SwallowMar 15-21Apr 1-7May 22-31Sep 1-733%
Barn SwallowApr 8-14Apr 22-30Jul 22-31Sep 1-731%
Chimney SwiftApr 22-30May 1-7Jun 1-7Sep 1-723%
Purple MartinApr 8-14Apr 22-30Jul 22-31Aug 15-2111%
Bank SwallowMay 1-7May 1-7Jul 15-21Sep 1-73.5%
0%10%20%30%40%Tree SwallowBarn SwallowChimney SwiftPurple MartinJanFebMarAprMayJunJulAugSepOctNovDec
  • Tree Swallow
  • Barn Swallow
  • Chimney Swift
  • Purple Martin
Share of complete checklists reporting each species, by week (4 per month). Gaps: fewer than 10 checklists that week.

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.

Where in Connecticut

Best counties for Tree Swallow

Share of checklists at the peak
  1. Litchfield CountyBest mid May · 2417 checklists that week, 69,766 in all42%
  2. New Haven CountyBest late May · 4805 checklists that week, 139,721 in all39%
  3. Windham CountyBest early June · 391 checklists that week, 19,034 in all38%
  4. Tolland CountyBest the second week of May · 1577 checklists that week, 39,004 in all32%
  5. Middlesex CountyBest the second week of May · 1592 checklists that week, 39,919 in all32%
  6. New London CountyBest mid May · 1754 checklists that week, 65,205 in all30%

All swallows in Connecticut

5 species are reported regularly: 5 are summer visitors.

#SpeciesPatternThrough the yearFirst arrivalsPeakPeak %
1Tree SwallowSummer visitorMar 15-21May 22-3133%
2Barn SwallowSummer visitorApr 8-14Jul 22-3131%
3Northern Rough-winged SwallowSummer visitorMar 22-31May 1-712%
4Purple MartinSummer visitorApr 8-14Jul 22-3111%
5Bank SwallowSummer visitorMay 1-7Jul 15-213.5%

Common questions

When do swallows arrive in Connecticut?
Tree Swallows reach Connecticut in mid March, are common by early April, peak in late May (33% of checklists), and most are gone by early September.
When do swallows leave Connecticut?
Most Tree Swallows have left Connecticut by early September, when reports fall below half their usual rate. Stragglers are still reported until late October.
When is the best time to see swallows in Connecticut?
The Tree Swallow is reported most often in late May, on about 33% of Connecticut checklists.
Which swallows are in Connecticut?
Tree Swallow, Barn Swallow, Chimney Swift, Purple Martin, and Bank Swallow are reported regularly; the Tree Swallow is the most common.