WhenToBird

Purple Martin · Progne subis

When Do Purple Martins Arrive in Iowa?

Adult female Purple Martin
Photo: Ron Bondy, CC BY-SA 4.0 via iNaturalist

Purple Martins reach Iowa in early April, are common by mid April, peak in early August (11% of checklists), and most are gone by late August.

When to look

First arrivalsApr 1-7early April
Common byApr 15-21mid April
PeakAug 1-7early August
Most gone byAug 22-31late August

Best: early August. First arrivals early April; most are gone by late August. Peak: on about 11% of Iowa checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marrare
  4. Apruncommon
  5. Maycommon
  6. Juncommon
  7. Julpeak season
  8. Augpeak season
  9. Sepuncommon
  10. Octnot usually seen
  11. Novnot usually seen
  12. Decnot usually seen

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

Purple Martins in Iowa, species by species

SpeciesFirst arrivalsCommon byPeakMost gone byPeak %
Purple MartinApr 1-7Apr 15-21Aug 1-7Aug 22-3111%
0%5%10%15%Purple MartinJanFebMarAprMayJunJulAugSepOctNovDec
  • 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 Iowa 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 Iowa

Best counties for Purple Martin

Share of checklists at the peak
  1. Calhoun CountyBest the second week of August · 11 checklists that week, 446 in all48%
  2. Montgomery CountyBest mid July · 10 checklists that week, 213 in all38%
  3. Dickinson CountyBest late July · 97 checklists that week, 2,030 in all37%
  4. Clarke CountyBest late July · 10 checklists that week, 459 in all31%
  5. Decatur CountyBest early August · 49 checklists that week, 2,962 in all30%
  6. Story CountyBest mid July · 196 checklists that week, 20,857 in all25%

Common questions

When do purple martins arrive in Iowa?
Purple Martins reach Iowa in early April, are common by mid April, peak in early August (11% of checklists), and most are gone by late August.
When do purple martins leave Iowa?
Most Purple Martins have left Iowa by late August, when reports fall below half their usual rate. Stragglers are still reported until early September.
When is the best time to see purple martins in Iowa?
The Purple Martin is reported most often in early August, on about 11% of Iowa checklists.