WhenToBird

Common Loon · Gavia immer

When Do Loons Arrive in Montana?

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

Common Loons are winter birds in Montana: they arrive in early April, peak in late October (8.5% of checklists), and most are gone by late November. They are the only regular loons in Montana.

When to look

First arrivalsApr 1-7early April
Common byApr 1-7early April
PeakOct 22-31late October
Most gone byNov 22-30late November

Best: late October. First arrivals early April; most are gone by late November. Peak: on about 8.5% of Montana checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marrare
  4. Aprcommon
  5. Maycommon
  6. Jununcommon
  7. Juluncommon
  8. Auguncommon
  9. Sepcommon
  10. Octpeak season
  11. Novpeak season
  12. Decrare

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

Loons in Montana, species by species

SpeciesFirst arrivalsCommon byPeakMost gone byPeak %
Common LoonApr 1-7Apr 1-7Oct 22-31Nov 22-308.5%
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 Montana 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 Montana

Best counties for Common Loon

Share of checklists at the peak
  1. Pondera CountyBest the second week of October · 12 checklists that week, 659 in all53%
  2. Madison CountyBest late October · 109 checklists that week, 7,008 in all50%
  3. Judith Basin CountyBest late October · 11 checklists that week, 650 in all39%
  4. Wheatland CountyBest early October · 10 checklists that week, 1,384 in all35%
  5. Lewis and Clark CountyBest late October · 648 checklists that week, 28,806 in all30%
  6. Rosebud CountyBest mid April · 11 checklists that week, 795 in all26%

Common questions

When do loons arrive in Montana?
Common Loons are winter birds in Montana: they arrive in early April, peak in late October (8.5% of checklists), and most are gone by late November. They are the only regular loons in Montana.
When do loons leave Montana?
Most Common Loons have left Montana by late November, when reports fall below half their usual rate.
When is the best time to see loons in Montana?
The Common Loon is reported most often in late October, on about 8.5% of Montana checklists.