WhenToBird

6 swallow species in Wisconsin

When Do Swallows Arrive in Wisconsin?

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 Wisconsin. Tree Swallows reach Wisconsin in late March, are common by early April, peak in the second week of May (36% of checklists), and most are gone by mid August.

When to look

First arrivalsMar 22-31late March
Common byApr 1-7early April
PeakMay 8-14the second week of May
Most gone byAug 15-21mid August

Best: the second week of May. First arrivals late March; most are gone by mid August. Peak: on about 36% of Wisconsin 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. Sepuncommon
  10. Octrare
  11. Novnot usually seen
  12. Decnot usually seen

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

Swallows in Wisconsin, species by species

SpeciesFirst arrivalsCommon byPeakMost gone byPeak %
Tree SwallowMar 22-31Apr 1-7May 8-14Aug 15-2136%
Barn SwallowApr 8-14Apr 22-30Aug 1-7Sep 1-733%
Chimney SwiftApr 22-30May 1-7Aug 1-7Sep 8-1411%
Purple MartinApr 8-14Apr 15-21Aug 1-7Aug 22-317.9%
Cliff SwallowApr 15-21May 1-7Jul 8-14Aug 15-217.0%
Bank SwallowApr 22-30Apr 22-30May 15-21Aug 22-313.8%
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 Wisconsin 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 Wisconsin

Best counties for Tree Swallow

Share of checklists at the peak
  1. Dodge CountyBest early June · 1223 checklists that week, 34,980 in all64%
  2. Taylor CountyBest the second week of May · 104 checklists that week, 4,326 in all60%
  3. Marquette CountyBest the second week of May · 178 checklists that week, 3,706 in all57%
  4. Calumet CountyBest the second week of May · 959 checklists that week, 12,359 in all56%
  5. Washburn CountyBest the second week of May · 355 checklists that week, 7,099 in all56%
  6. Green Lake CountyBest early May · 737 checklists that week, 15,345 in all51%

All swallows in Wisconsin

6 species are reported regularly: 6 are summer visitors.

#SpeciesPatternThrough the yearFirst arrivalsPeakPeak %
1Tree SwallowSummer visitorMar 22-31May 8-1436%
2Barn SwallowSummer visitorApr 8-14Aug 1-733%
3Northern Rough-winged SwallowSummer visitorApr 8-14May 8-1411%
4Purple MartinSummer visitorApr 8-14Aug 1-77.9%
5Cliff SwallowSummer visitorApr 15-21Jul 8-147.0%
6Bank SwallowSummer visitorApr 22-30May 15-213.8%

Common questions

When do swallows arrive in Wisconsin?
Tree Swallows reach Wisconsin in late March, are common by early April, peak in the second week of May (36% of checklists), and most are gone by mid August.
When do swallows leave Wisconsin?
Most Tree Swallows have left Wisconsin by mid August, when reports fall below half their usual rate. Stragglers are still reported until the second week of October.
When is the best time to see swallows in Wisconsin?
The Tree Swallow is reported most often in the second week of May, on about 36% of Wisconsin checklists.
Which swallows are in Wisconsin?
Tree Swallow, Barn Swallow, Chimney Swift, Purple Martin, Cliff Swallow, and Bank Swallow are reported regularly; the Tree Swallow is the most common.