WhenToBird

Sialia mexicana · Turdidae

When Do Western Bluebirds Arrive in Arizona?

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

Western Bluebirds are in Arizona all year, but most are here in winter: numbers build from late October, peak in mid December (12% of checklists), and fall back by late February. In the quietest week (the second week of April) they are still on about 3.6% of checklists.

When to look

Numbers buildOct 22-31late October
PeakDec 15-21mid December
Fall back byFeb 22-28late February
FewestApr 8-14the second week of April

Best: mid December. Here all year; numbers build from late October and fall back by late February. Peak: on about 12% of Arizona checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marcommon
  4. Apruncommon
  5. Maycommon
  6. Juncommon
  7. Julcommon
  8. Augcommon
  9. Sepcommon
  10. Octcommon
  11. Novpeak season
  12. Decpeak season

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

0%5%10%15%Jan 1-7: 11% of 34758 checklistsJan 8-14: 9.7% of 29835 checklistsJan 15-21: 9.5% of 29279 checklistsJan 22-31: 9.5% of 39716 checklistsFeb 1-7: 9.2% of 27299 checklistsFeb 8-14: 8.8% of 28703 checklistsFeb 15-21: 7.7% of 35357 checklistsFeb 22-28: 8.4% of 29889 checklistsMar 1-7: 7.4% of 29932 checklistsMar 8-14: 6.1% of 32982 checklistsMar 15-21: 4.7% of 34731 checklistsMar 22-31: 3.7% of 50213 checklistsApr 1-7: 3.6% of 35788 checklistsApr 8-14: 3.6% of 38087 checklistsApr 15-21: 3.7% of 41520 checklistsApr 22-30: 3.6% of 55218 checklistsMay 1-7: 3.8% of 39688 checklistsMay 8-14: 4.1% of 39398 checklistsMay 15-21: 4.2% of 29562 checklistsMay 22-31: 4.6% of 36774 checklistsJun 1-7: 5.5% of 21313 checklistsJun 8-14: 6.3% of 19129 checklistsJun 15-21: 5.8% of 17922 checklistsJun 22-30: 6.0% of 21188 checklistsJul 1-7: 5.7% of 17325 checklistsJul 8-14: 5.8% of 16463 checklistsJul 15-21: 4.9% of 18642 checklistsJul 22-31: 4.5% of 31215 checklistsAug 1-7: 4.2% of 28163 checklistsAug 8-14: 4.5% of 31329 checklistsAug 15-21: 5.2% of 23878 checklistsAug 22-31: 5.4% of 28508 checklistsSep 1-7: 5.4% of 20878 checklistsSep 8-14: 5.9% of 19671 checklistsSep 15-21: 6.4% of 19859 checklistsSep 22-30: 6.5% of 25179 checklistsOct 1-7: 6.2% of 19420 checklistsOct 8-14: 6.4% of 21925 checklistsOct 15-21: 6.5% of 20995 checklistsOct 22-31: 8.1% of 29258 checklistsNov 1-7: 10% of 21269 checklistsNov 8-14: 10% of 22753 checklistsNov 15-21: 11% of 21982 checklistsNov 22-30: 10% of 29475 checklistsDec 1-7: 10% of 20810 checklistsDec 8-14: 11% of 22229 checklistsDec 15-21: 13% of 25148 checklistsDec 22-31: 11% of 39567 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 Arizona 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 Arizona

Best counties

Share of checklists at the peak
  1. Coconino CountyBest early October · 1959 checklists that week, 90,870 in all39%
  2. Yavapai CountyBest the second week of November · 1308 checklists that week, 83,606 in all37%
  3. Greenlee CountyBest mid November · 12 checklists that week, 2,745 in all33%
  4. Apache CountyBest the second week of January · 113 checklists that week, 12,931 in all26%
  5. Gila CountyBest late November · 261 checklists that week, 14,834 in all25%
  6. Navajo CountyBest late October · 297 checklists that week, 18,838 in all24%

Best spots

Share of checklists at the peak
  1. Bottomless PitCoconino County, best early September · 38 checklists that week, 2,433 in all85%
  2. Grand Canyon National ParkCoconino County, best the second week of October · 46 checklists that week, 1,669 in all83%
  3. Domingo TankCoconino County, best late May · 21 checklists that week, 144 in all83%

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

Best time of day

In Arizona, the Western Bluebird is most often listed on checklists started between 8 and 10 am (8.3% of those checklists).

0%5%10%12 am: too few checklists (488) to judge1 am: too few checklists (503) to judge2 am: too few checklists (489) to judge3 am: too few checklists (735) to judge4 am: too few checklists (4115) to judge5 am: 3.4% of 38350 checklists6 am: 4.7% of 118786 checklists7 am: 7.2% of 183415 checklists8 am: 8.5% of 187346 checklists9 am: 8.1% of 151342 checklists10 am: 7.3% of 124522 checklists11 am: 6.9% of 97088 checklists12 pm: 6.7% of 78110 checklists1 pm: 6.5% of 73059 checklists2 pm: 6.8% of 68912 checklists3 pm: 6.9% of 68060 checklists4 pm: 6.1% of 69387 checklists5 pm: 3.9% of 52951 checklists6 pm: 2.6% of 31061 checklists7 pm: too few checklists (16076) to judge8 pm: too few checklists (5352) to judge9 pm: too few checklists (2369) to judge10 pm: too few checklists (1100) to judge11 pm: too few checklists (604) 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
January11%9.7%9.5%9.5%
February9.2%8.8%7.7%8.4%
March7.4%6.1%4.7%3.7%
April3.6%3.6%3.7%3.6%
May3.8%4.1%4.2%4.6%
June5.5%6.3%5.8%6.0%
July5.7%5.8%4.9%4.5%
August4.2%4.5%5.2%5.4%
September5.4%5.9%6.4%6.5%
October6.2%6.4%6.5%8.1%
November10%10%11%10%
December10%11%13%11%

Neighboring states

  • New Mexico: year-round, peaks late October
  • Nevada: year-round, peaks early March
  • Utah: arrives mid January, 11 weeks later than Arizona
  • California: year-round, peaks late March

Common questions

When do Western Bluebirds arrive in Arizona?
Western Bluebirds are in Arizona all year, but most are here in winter: numbers build from late October, peak in mid December (12% of checklists), and fall back by late February. In the quietest week (the second week of April) they are still on about 3.6% of checklists.
When do Western Bluebirds leave Arizona?
Western Bluebirds never fully leave Arizona: numbers fall back below half their usual rate by late February, but some are still reported in every week, about 3.6% of checklists at the low.
When is the best time to see a Western Bluebird in Arizona?
The Western Bluebird is reported most often in mid December, on about 12% of Arizona checklists.
Where in Arizona are Western Bluebirds seen most often?
By county, Coconino County, Yavapai County, and Greenlee County have the highest peak reporting rates for the Western Bluebird (counties with at least 200 checklists).