WhenToBird

Common Loon · Gavia immer

When Do Loons Arrive in Wyoming?

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

Common Loons are winter birds in Wyoming: they arrive in early October, peak in early November (6.6% of checklists), and most are gone by early December. They are the only regular loons in Wyoming.

When to look

First arrivalsOct 1-7early October
Common byOct 1-7early October
PeakNov 1-7early November
Most gone byDec 1-7early December

Best: early November. First arrivals early October; most are gone by early December. Peak: on about 6.6% of Wyoming checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marrare
  4. Aprcommon
  5. Mayuncommon
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Seprare
  10. Octpeak season
  11. Novpeak season
  12. Decuncommon

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

Loons in Wyoming, species by species

SpeciesFirst arrivalsCommon byPeakMost gone byPeak %
Common LoonOct 1-7Oct 1-7Nov 1-7Dec 1-76.6%
0%2%4%6%8%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 Wyoming 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 Wyoming

Best counties for Common Loon

Share of checklists at the peak
  1. Carbon CountyBest the second week of November · 42 checklists that week, 6,429 in all28%
  2. Johnson CountyBest late October · 159 checklists that week, 5,977 in all24%
  3. Natrona CountyBest mid April · 158 checklists that week, 5,810 in all17%
  4. Sweetwater CountyBest early November · 23 checklists that week, 5,064 in all15%
  5. Platte CountyBest early November · 12 checklists that week, 1,645 in all14%
  6. Uinta CountyBest mid April · 48 checklists that week, 1,881 in all14%

Common questions

When do loons arrive in Wyoming?
Common Loons are winter birds in Wyoming: they arrive in early October, peak in early November (6.6% of checklists), and most are gone by early December. They are the only regular loons in Wyoming.
When do loons leave Wyoming?
Most Common Loons have left Wyoming by early December, when reports fall below half their usual rate.
When is the best time to see loons in Wyoming?
The Common Loon is reported most often in early November, on about 6.6% of Wyoming checklists.