WhenToBird

Sialia mexicana · Turdidae

When Do Western Bluebirds Arrive in Montana?

Adult male Western Bluebird
Photo: sprcrkwild, CC BY 4.0 via iNaturalist

Western Bluebirds arrive in Montana in early March, peak in the second week of April (3.1% of checklists), and most are gone by mid October.

When to look

First arrivalsMar 1-7early March
Common byMar 1-7early March
PeakApr 8-14the second week of April
Most gone byOct 15-21mid October

Best: the second week of April. First arrivals early March; most are gone by mid October. Peak: on about 3.1% of Montana checklists.

  1. Janrare
  2. Febrare
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Juncommon
  7. Juluncommon
  8. Auguncommon
  9. Sepuncommon
  10. Octuncommon
  11. Novrare
  12. Decrare

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

0%1%2%3%4%Jan 1-7: 0.2% of 7987 checklistsJan 8-14: 0.2% of 5561 checklistsJan 15-21: 0.2% of 5613 checklistsJan 22-31: 0.2% of 7881 checklistsFeb 1-7: 0.1% of 5018 checklistsFeb 8-14: 0.1% of 5598 checklistsFeb 15-21: 0% of 7247 checklistsFeb 22-28: 0.2% of 5531 checklistsMar 1-7: 0.8% of 6110 checklistsMar 8-14: 1.9% of 6623 checklistsMar 15-21: 2.5% of 7687 checklistsMar 22-31: 2.8% of 11095 checklistsApr 1-7: 3.1% of 7774 checklistsApr 8-14: 3.2% of 8785 checklistsApr 15-21: 2.9% of 9684 checklistsApr 22-30: 2.4% of 13805 checklistsMay 1-7: 2.3% of 11847 checklistsMay 8-14: 2.3% of 13547 checklistsMay 15-21: 2.0% of 13019 checklistsMay 22-31: 1.7% of 20456 checklistsJun 1-7: 1.5% of 12993 checklistsJun 8-14: 1.4% of 11594 checklistsJun 15-21: 1.5% of 11159 checklistsJun 22-30: 1.3% of 13786 checklistsJul 1-7: 1.2% of 9584 checklistsJul 8-14: 0.7% of 9078 checklistsJul 15-21: 1.0% of 7905 checklistsJul 22-31: 0.9% of 10906 checklistsAug 1-7: 0.7% of 7335 checklistsAug 8-14: 0.9% of 6868 checklistsAug 15-21: 0.7% of 6866 checklistsAug 22-31: 0.8% of 10076 checklistsSep 1-7: 0.6% of 7670 checklistsSep 8-14: 0.7% of 7490 checklistsSep 15-21: 0.9% of 6804 checklistsSep 22-30: 1.0% of 8016 checklistsOct 1-7: 1.1% of 5996 checklistsOct 8-14: 1.1% of 6156 checklistsOct 15-21: 0.8% of 5742 checklistsOct 22-31: 0.4% of 7790 checklistsNov 1-7: 0.1% of 5353 checklistsNov 8-14: 0.2% of 5475 checklistsNov 15-21: 0.1% of 4603 checklistsNov 22-30: 0.1% of 6067 checklistsDec 1-7: 0.3% of 4362 checklistsDec 8-14: 0.2% of 4467 checklistsDec 15-21: 0.2% of 5328 checklistsDec 22-31: 0.3% 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. Mineral CountyBest the second week of April · 48 checklists that week, 2,163 in all15%
  2. Sanders CountyBest the second week of April · 72 checklists that week, 3,767 in all12%
  3. Missoula CountyBest the second week of April · 1799 checklists that week, 64,368 in all8.2%
  4. Jefferson CountyBest mid April · 312 checklists that week, 14,859 in all7.4%
  5. Lincoln CountyBest early October · 56 checklists that week, 5,543 in all6.6%
  6. Ravalli CountyBest early May · 496 checklists that week, 16,671 in all5.0%

Best spots

Share of checklists at the peak
  1. Blue Mountain Nature National Recreation TrailMissoula County, best early June · 20 checklists that week, 177 in all67%
  2. Thompson Falls ReservoirSanders County, best late April · 24 checklists that week, 414 in all38%
  3. Lolo National ForestMissoula County, best the second week of May · 50 checklists that week, 2,195 in all30%

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

Best time of day

In Montana, the Western Bluebird is most often listed on checklists started between 6 and 8 am (1.8% of those checklists).

0%0.5%1%1.5%2%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: 1.8% of 12719 checklists7 am: 1.8% of 31202 checklists8 am: 1.5% of 47646 checklists9 am: 1.3% of 44624 checklists10 am: 1.3% of 40704 checklists11 am: 1.1% of 33825 checklists12 pm: 0.9% of 29407 checklists1 pm: 0.9% of 27959 checklists2 pm: 0.8% of 26928 checklists3 pm: 1.0% of 25313 checklists4 pm: 1.1% of 22151 checklists5 pm: 1.3% of 16884 checklists6 pm: 1.4% of 13780 checklists7 pm: 1.3% 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
January0.2%0.2%0.2%0.2%
February0.1%0.1%0%0.2%
March0.8%1.9%2.5%2.8%
April3.1%3.2%2.9%2.4%
May2.3%2.3%2.0%1.7%
June1.5%1.4%1.5%1.3%
July1.2%0.7%1.0%0.9%
August0.7%0.9%0.7%0.8%
September0.6%0.7%0.9%1.0%
October1.1%1.1%0.8%0.4%
November0.1%0.2%0.1%0.1%
December0.3%0.2%0.2%0.3%

Neighboring states

  • Idaho: arrives early March, in the same week than Montana
  • Utah: arrives mid January, 6 weeks earlier than Montana
  • Washington: arrives early March, in the same week than Montana
  • Oregon: year-round, peaks the second week of March

Common questions

When do Western Bluebirds arrive in Montana?
Western Bluebirds arrive in Montana in early March, peak in the second week of April (3.1% of checklists), and most are gone by mid October.
When do Western Bluebirds leave Montana?
Most Western Bluebirds have left Montana by mid October, when reports fall below half their usual rate.
When is the best time to see a Western Bluebird in Montana?
The Western Bluebird is reported most often in the second week of April, on about 3.1% of Montana checklists.
Where in Montana are Western Bluebirds seen most often?
By county, Mineral County, Sanders County, and Missoula County have the highest peak reporting rates for the Western Bluebird (counties with at least 200 checklists).