WhenToBird

Common Loon · Gavia immer

When Do Loons Arrive in Iowa?

Adult Common Loon
Photo: Hungry-Sarracenia Photo, CC BY 4.0 via iNaturalist

Common Loons are winter birds in Iowa: they arrive in the second week of October, peak in the second week of November (7.4% of checklists), and most are gone by the second week of December. They are the only regular loons in Iowa.

When to look

First arrivalsOct 8-14the second week of October
Common byOct 8-14the second week of October
PeakNov 8-14the second week of November
Most gone byDec 8-14the second week of December

Best: the second week of November. First arrivals the second week of October; most are gone by the second week of December. Peak: on about 7.4% of Iowa checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marcommon
  4. Aprcommon
  5. Mayrare
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augrare
  9. Sepnot usually seen
  10. Octcommon
  11. Novpeak season
  12. Decuncommon

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

Loons in Iowa, species by species

SpeciesFirst arrivalsCommon byPeakMost gone byPeak %
Common LoonOct 8-14Oct 8-14Nov 8-14Dec 8-147.4%
0%5%10%Common LoonJanFebMarAprMayJunJulAugSepOctNovDec
  • Common Loon
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 Common Loon

Share of checklists at the peak
  1. Webster CountyBest the second week of August · 14 checklists that week, 635 in all70%
  2. Marion CountyBest the second week of November · 59 checklists that week, 3,389 in all42%
  3. Polk CountyBest the second week of November · 587 checklists that week, 37,521 in all24%
  4. Cerro Gordo CountyBest the second week of November · 23 checklists that week, 1,853 in all23%
  5. Appanoose CountyBest early April · 21 checklists that week, 820 in all20%
  6. Palo Alto CountyBest early April · 11 checklists that week, 460 in all20%

Common questions

When do loons arrive in Iowa?
Common Loons are winter birds in Iowa: they arrive in the second week of October, peak in the second week of November (7.4% of checklists), and most are gone by the second week of December. They are the only regular loons in Iowa.
When do loons leave Iowa?
Most Common Loons have left Iowa by the second week of December, when reports fall below half their usual rate.
When is the best time to see loons in Iowa?
The Common Loon is reported most often in the second week of November, on about 7.4% of Iowa checklists.