WhenToBird

Peucaea cassinii · Passerellidae

When Do Cassin's Sparrows Arrive in Arizona?

Adult Cassin's Sparrow
Photo: Dan Vickers, CC BY 4.0 via iNaturalist

Cassin's Sparrows mostly pass through Arizona: they arrive in the second week of July, peak in early August (3.2% of checklists), and most are gone by late August.

When to look

First arrivalsJul 8-14the second week of July
Common byJul 8-14the second week of July
PeakAug 1-7early August
Most gone byAug 22-31late August

Best: early August. First arrivals the second week of July; most are gone by late August. Peak: on about 3.2% of Arizona checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marrare
  4. Aprrare
  5. Maynot usually seen
  6. Junrare
  7. Julpeak season
  8. Augpeak season
  9. Sepuncommon
  10. Octrare
  11. Novnot usually seen
  12. Decnot usually seen

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

0%1%2%3%4%Jan 1-7: 0.1% of 34758 checklistsJan 8-14: 0.1% of 29835 checklistsJan 15-21: 0.1% of 29279 checklistsJan 22-31: 0.1% of 39716 checklistsFeb 1-7: 0.1% of 27299 checklistsFeb 8-14: 0.1% of 28703 checklistsFeb 15-21: 0.1% of 35357 checklistsFeb 22-28: 0.1% of 29889 checklistsMar 1-7: 0.1% of 29932 checklistsMar 8-14: 0.2% of 32982 checklistsMar 15-21: 0.3% of 34731 checklistsMar 22-31: 0.3% of 50213 checklistsApr 1-7: 0.2% of 35788 checklistsApr 8-14: 0.1% of 38087 checklistsApr 15-21: 0.2% of 41520 checklistsApr 22-30: 0.1% of 55218 checklistsMay 1-7: 0.1% of 39688 checklistsMay 8-14: 0.1% of 39398 checklistsMay 15-21: 0.1% of 29562 checklistsMay 22-31: 0.1% of 36774 checklistsJun 1-7: 0.2% of 21313 checklistsJun 8-14: 0.1% of 19129 checklistsJun 15-21: 0.1% of 17922 checklistsJun 22-30: 0.3% of 21188 checklistsJul 1-7: 0.7% of 17325 checklistsJul 8-14: 1.3% of 16463 checklistsJul 15-21: 1.8% of 18642 checklistsJul 22-31: 2.7% of 31215 checklistsAug 1-7: 3.4% of 28163 checklistsAug 8-14: 3.5% of 31329 checklistsAug 15-21: 2.4% of 23878 checklistsAug 22-31: 1.7% of 28508 checklistsSep 1-7: 1.1% of 20878 checklistsSep 8-14: 0.5% of 19671 checklistsSep 15-21: 0.4% of 19859 checklistsSep 22-30: 0.2% of 25179 checklistsOct 1-7: 0.2% of 19420 checklistsOct 8-14: 0.1% of 21925 checklistsOct 15-21: 0.1% of 20995 checklistsOct 22-31: 0.1% of 29258 checklistsNov 1-7: 0.1% of 21269 checklistsNov 8-14: 0.1% of 22753 checklistsNov 15-21: 0.1% of 21982 checklistsNov 22-30: 0.1% of 29475 checklistsDec 1-7: 0.1% of 20810 checklistsDec 8-14: 0.1% of 22229 checklistsDec 15-21: 0.1% of 25148 checklistsDec 22-31: 0.1% 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. Cochise CountyBest late July · 6551 checklists that week, 190,093 in all5.1%
  2. Greenlee CountyBest late September · 49 checklists that week, 2,745 in all4.9%
  3. Pima CountyBest the second week of August · 11199 checklists that week, 437,722 in all4.1%
  4. Santa Cruz CountyBest late July · 4081 checklists that week, 162,726 in all3.8%
  5. Pinal CountyBest mid August · 548 checklists that week, 40,036 in all3.0%
  6. Yavapai CountyBest the second week of August · 979 checklists that week, 83,606 in all1.8%

Best spots

Share of checklists at the peak
  1. Smith CanyonSanta Cruz County, best early August · 101 checklists that week, 900 in all76%
  2. Empire-Cienega Area of Critical Environmental Concern (southwest)Pima County, best early August · 44 checklists that week, 835 in all69%
  3. Empire-Cienega Area of Critical Environmental Concern (Los Posos Gulch)Pima County, best early August · 22 checklists that week, 399 in all62%
  4. Santa Rita Experimental Range (south)Pima County, best mid August · 23 checklists that week, 777 in all54%
  5. Santa Rita Experimental RangePima County, best mid August · 44 checklists that week, 1,025 in all53%

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

Best time of day

In Arizona, the Cassin's Sparrow is most often listed on checklists started between 5 and 7 am (1.2% of those checklists).

0%0.5%1%1.5%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: 1.3% of 38350 checklists6 am: 1.1% of 118786 checklists7 am: 0.6% of 183415 checklists8 am: 0.4% of 187346 checklists9 am: 0.3% of 151342 checklists10 am: 0.3% of 124522 checklists11 am: 0.3% of 97088 checklists12 pm: 0.3% of 78110 checklists1 pm: 0.3% of 73059 checklists2 pm: 0.3% of 68912 checklists3 pm: 0.3% of 68060 checklists4 pm: 0.3% of 69387 checklists5 pm: 0.3% of 52951 checklists6 pm: 0.5% 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
January0.1%0.1%0.1%0.1%
February0.1%0.1%0.1%0.1%
March0.1%0.2%0.3%0.3%
April0.2%0.1%0.2%0.1%
May0.1%0.1%0.1%0.1%
June0.2%0.1%0.1%0.3%
July0.7%1.3%1.8%2.7%
August3.4%3.5%2.4%1.7%
September1.1%0.5%0.4%0.2%
October0.2%0.1%0.1%0.1%
November0.1%0.1%0.1%0.1%
December0.1%0.1%0.1%0.1%

Neighboring states

  • New Mexico: arrives mid April, 11 weeks earlier than Arizona
  • Colorado: arrives early May, 9 weeks earlier than Arizona
  • Texas: arrives the second week of March, 16 weeks earlier than Arizona
  • Oklahoma: arrives late April, 10 weeks earlier than Arizona

Common questions

When do Cassin's Sparrows arrive in Arizona?
Cassin's Sparrows mostly pass through Arizona: they arrive in the second week of July, peak in early August (3.2% of checklists), and most are gone by late August.
When do Cassin's Sparrows leave Arizona?
Most Cassin's Sparrows have left Arizona by late August, when reports fall below half their usual rate. Stragglers are still reported until early September.
When is the best time to see a Cassin's Sparrow in Arizona?
The Cassin's Sparrow is reported most often in early August, on about 3.2% of Arizona checklists.
Where in Arizona are Cassin's Sparrows seen most often?
By county, Cochise County, Greenlee County, and Pima County have the highest peak reporting rates for the Cassin's Sparrow (counties with at least 200 checklists).