WhenToBird

Haemorhous cassinii · Fringillidae

When Do Cassin's Finches Arrive in Montana?

Adult male Cassin's Finch
Photo: Craig Martin, CC0 1.0 via iNaturalist

Cassin's Finches reach Montana in late January, are common by mid March, peak in the second week of May (8.4% of checklists), and most are gone by the second week of October.

When to look

First arrivalsJan 22-31late January
Common byMar 15-21mid March
PeakMay 8-14the second week of May
Most gone byOct 8-14the second week of October

Best: the second week of May. First arrivals late January; most are gone by the second week of October. Peak: on about 8.4% of Montana checklists.

  1. Janrare
  2. Febuncommon
  3. Maruncommon
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julcommon
  8. Augcommon
  9. Sepcommon
  10. Octuncommon
  11. Novuncommon
  12. Decrare

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

0%5%10%Jan 1-7: 0.6% of 7987 checklistsJan 8-14: 0.6% of 5561 checklistsJan 15-21: 0.9% of 5613 checklistsJan 22-31: 1.1% of 7881 checklistsFeb 1-7: 1.6% of 5018 checklistsFeb 8-14: 2.6% of 5598 checklistsFeb 15-21: 1.7% of 7247 checklistsFeb 22-28: 1.5% of 5531 checklistsMar 1-7: 1.2% of 6110 checklistsMar 8-14: 1.3% of 6623 checklistsMar 15-21: 1.9% of 7687 checklistsMar 22-31: 2.9% of 11095 checklistsApr 1-7: 3.0% of 7774 checklistsApr 8-14: 3.7% of 8785 checklistsApr 15-21: 4.8% of 9684 checklistsApr 22-30: 6.6% of 13805 checklistsMay 1-7: 8.3% of 11847 checklistsMay 8-14: 8.2% of 13547 checklistsMay 15-21: 8.5% of 13019 checklistsMay 22-31: 7.0% of 20456 checklistsJun 1-7: 5.9% of 12993 checklistsJun 8-14: 6.0% of 11594 checklistsJun 15-21: 6.0% of 11159 checklistsJun 22-30: 5.5% of 13786 checklistsJul 1-7: 5.8% of 9584 checklistsJul 8-14: 4.5% of 9078 checklistsJul 15-21: 4.4% of 7905 checklistsJul 22-31: 4.4% of 10906 checklistsAug 1-7: 4.0% of 7335 checklistsAug 8-14: 3.9% of 6868 checklistsAug 15-21: 3.1% of 6866 checklistsAug 22-31: 3.3% of 10076 checklistsSep 1-7: 2.8% of 7670 checklistsSep 8-14: 2.3% of 7490 checklistsSep 15-21: 3.3% of 6804 checklistsSep 22-30: 3.8% of 8016 checklistsOct 1-7: 3.2% of 5996 checklistsOct 8-14: 2.2% of 6156 checklistsOct 15-21: 1.9% of 5742 checklistsOct 22-31: 1.9% of 7790 checklistsNov 1-7: 1.1% of 5353 checklistsNov 8-14: 1.3% of 5475 checklistsNov 15-21: 1.5% of 4603 checklistsNov 22-30: 0.9% of 6067 checklistsDec 1-7: 0.7% of 4362 checklistsDec 8-14: 0.7% of 4467 checklistsDec 15-21: 0.7% of 5328 checklistsDec 22-31: 0.6% of 6672 checklistsJanFebMarAprMayJunJulAugSepOctNovDec
Share of complete checklists reporting it, by week (4 per month). Grey bars: fewer than 10 checklists, not counted.

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.

JanFebMarAprMayJunJulAugSepOctNovDec
today
Second week of November

Each county is shaded by the share of complete checklists there that listed the bird, blended with the weeks either side. Darker is more often. It follows where people watch birds, not how many birds there are. How to read it.

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Where in Montana

Best counties

Share of checklists at the peak
  1. Jefferson CountyBest the second week of May · 393 checklists that week, 14,859 in all36%
  2. Sanders CountyBest early May · 83 checklists that week, 3,767 in all27%
  3. Mineral CountyBest the second week of May · 48 checklists that week, 2,163 in all26%
  4. Beaverhead CountyBest the second week of May · 290 checklists that week, 8,224 in all19%
  5. Meagher CountyBest early April · 10 checklists that week, 1,201 in all19%
  6. Carbon CountyBest the second week of May · 173 checklists that week, 8,743 in all19%

Best spots

Share of checklists at the peak
  1. Thompson Falls ReservoirSanders County, best late May · 23 checklists that week, 414 in all61%
  2. Greer GulchJefferson County, best late May · 24 checklists that week, 197 in all57%
  3. Bear CreekCarbon County, best mid May · 21 checklists that week, 207 in all55%
  4. Lewis and Clark Caverns State Park (Dolomite Knob)Jefferson County, best late May · 20 checklists that week, 308 in all52%
  5. Blue Mountain Nature National Recreation TrailMissoula County, best early June · 20 checklists that week, 177 in all49%

Busy spots report more of everything; compare the checklist counts before you drive anywhere.

Best time of day

In Montana, the Cassin's Finch is most often listed on checklists started between 6 and 8 am (8.0% of those checklists).

0%5%10%12 am: too few checklists (183) to judge1 am: too few checklists (169) to judge2 am: too few checklists (163) to judge3 am: too few checklists (212) to judge4 am: too few checklists (503) to judge5 am: too few checklists (4022) to judge6 am: 8.0% of 12719 checklists7 am: 8.1% of 31202 checklists8 am: 5.5% of 47646 checklists9 am: 4.1% of 44624 checklists10 am: 3.2% of 40704 checklists11 am: 2.9% of 33825 checklists12 pm: 2.8% of 29407 checklists1 pm: 2.6% of 27959 checklists2 pm: 2.4% of 26928 checklists3 pm: 2.4% of 25313 checklists4 pm: 2.7% of 22151 checklists5 pm: 4.1% of 16884 checklists6 pm: 3.8% of 13780 checklists7 pm: 3.3% of 9926 checklists8 pm: too few checklists (5765) to judge9 pm: too few checklists (2099) to judge10 pm: too few checklists (595) to judge11 pm: too few checklists (230) to judge12a3a6a9a12p3p6p9p
Share of checklists started in each local hour that reported it. It reflects when people go birding as well as when birds are active. Grey hours have too few checklists (under 2% of the state’s, or under 200) to judge.
Week-by-week table
MonthDays 1-78-1415-2122-end
January0.6%0.6%0.9%1.1%
February1.6%2.6%1.7%1.5%
March1.2%1.3%1.9%2.9%
April3.0%3.7%4.8%6.6%
May8.3%8.2%8.5%7.0%
June5.9%6.0%6.0%5.5%
July5.8%4.5%4.4%4.4%
August4.0%3.9%3.1%3.3%
September2.8%2.3%3.3%3.8%
October3.2%2.2%1.9%1.9%
November1.1%1.3%1.5%0.9%
December0.7%0.7%0.7%0.6%

Neighboring states

  • Idaho: arrives mid January, 1 week earlier than Montana
  • Wyoming: arrives the second week of January, 2 weeks earlier than Montana
  • Utah: arrives the second week of January, 2 weeks earlier than Montana
  • Washington: arrives the second week of April, 10 weeks later than Montana

Common questions

When do Cassin's Finches arrive in Montana?
Cassin's Finches reach Montana in late January, are common by mid March, peak in the second week of May (8.4% of checklists), and most are gone by the second week of October.
When do Cassin's Finches leave Montana?
Most Cassin's Finches have left Montana by the second week of October, when reports fall below half their usual rate. Stragglers are still reported until late November.
When is the best time to see a Cassin's Finch in Montana?
The Cassin's Finch is reported most often in the second week of May, on about 8.4% of Montana checklists.
Where in Montana are Cassin's Finches seen most often?
By county, Jefferson County, Sanders County, and Mineral County have the highest peak reporting rates for the Cassin's Finch (counties with at least 200 checklists).