WhenToBird

Zonotrichia albicollis · Passerellidae

When Do White-throated Sparrows Arrive in Colorado?

Adult White-throated Sparrow
Photo: northerly, CC BY 4.0 via iNaturalist

White-throated Sparrows are winter birds in Colorado: they arrive in late September, peak in mid October (1.8% of checklists), and most are gone by the second week of May.

When to look

First arrivalsSep 22-30late September
Common bySep 22-30late September
PeakOct 15-21mid October
Most gone byMay 8-14the second week of May

Best: mid October. First arrivals late September; most are gone by the second week of May. Peak: on about 1.8% of Colorado checklists.

  1. Jancommon
  2. Febuncommon
  3. Maruncommon
  4. Apruncommon
  5. Mayuncommon
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepuncommon
  10. Octpeak season
  11. Novpeak season
  12. Deccommon

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

0%0.5%1%1.5%2%Jan 1-7: 0.8% of 32254 checklistsJan 8-14: 0.7% of 23278 checklistsJan 15-21: 0.7% of 22933 checklistsJan 22-31: 0.8% of 30856 checklistsFeb 1-7: 0.7% of 21464 checklistsFeb 8-14: 0.6% of 22910 checklistsFeb 15-21: 0.4% of 28739 checklistsFeb 22-28: 0.5% of 21833 checklistsMar 1-7: 0.4% of 23066 checklistsMar 8-14: 0.5% of 23783 checklistsMar 15-21: 0.5% of 24797 checklistsMar 22-31: 0.4% of 38439 checklistsApr 1-7: 0.4% of 31676 checklistsApr 8-14: 0.3% of 35092 checklistsApr 15-21: 0.4% of 36778 checklistsApr 22-30: 0.5% of 50885 checklistsMay 1-7: 0.5% of 44186 checklistsMay 8-14: 0.4% of 49011 checklistsMay 15-21: 0.2% of 40784 checklistsMay 22-31: 0.1% of 53073 checklistsJun 1-7: 0.1% of 32432 checklistsJun 8-14: 0.1% of 29978 checklistsJun 15-21: 0% of 29457 checklistsJun 22-30: 0% of 36072 checklistsJul 1-7: 0% of 28857 checklistsJul 8-14: 0% of 27224 checklistsJul 15-21: 0% of 27629 checklistsJul 22-31: 0% of 37318 checklistsAug 1-7: 0% of 25893 checklistsAug 8-14: 0% of 24870 checklistsAug 15-21: 0% of 24035 checklistsAug 22-31: 0.1% of 35691 checklistsSep 1-7: 0.1% of 27068 checklistsSep 8-14: 0.1% of 26709 checklistsSep 15-21: 0.2% of 26098 checklistsSep 22-30: 0.6% of 31550 checklistsOct 1-7: 1.2% of 24110 checklistsOct 8-14: 1.6% of 23352 checklistsOct 15-21: 1.9% of 21895 checklistsOct 22-31: 1.8% of 28319 checklistsNov 1-7: 1.3% of 21698 checklistsNov 8-14: 0.9% of 21061 checklistsNov 15-21: 0.9% of 19855 checklistsNov 22-30: 0.9% of 25798 checklistsDec 1-7: 0.7% of 18626 checklistsDec 8-14: 0.8% of 19004 checklistsDec 15-21: 0.7% of 23103 checklistsDec 22-31: 0.7% of 30802 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 Colorado 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 Colorado

Best counties

Share of checklists at the peak
  1. Baca CountyBest late October · 26 checklists that week, 3,209 in all23%
  2. San Miguel CountyBest early November · 88 checklists that week, 8,094 in all16%
  3. Prowers CountyBest mid October · 143 checklists that week, 11,307 in all14%
  4. Sedgwick CountyBest the second week of October · 17 checklists that week, 1,168 in all8.8%
  5. Crowley CountyBest early October · 62 checklists that week, 1,883 in all8.2%
  6. Yuma CountyBest early October · 139 checklists that week, 3,844 in all7.6%

Best spots

Share of checklists at the peak
  1. NorwoodSan Miguel County, best late October · 36 checklists that week, 1,247 in all44%
  2. Heron Pond/Heller Open SpaceDenver County, best late September · 32 checklists that week, 924 in all39%
  3. Waneka Lake ParkBoulder County, best early February · 142 checklists that week, 6,926 in all26%
  4. Greenlee Wildlife Preserve Open SpaceBoulder County, best early February · 25 checklists that week, 800 in all26%
  5. Spring Canyon Community ParkLarimer County, best late October · 24 checklists that week, 799 in all22%

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

Best time of day

In Colorado, the White-throated Sparrow is most often listed on checklists started between 7 and 9 am (0.6% of those checklists).

0%0.5%1%12 am: too few checklists (512) to judge1 am: too few checklists (468) to judge2 am: too few checklists (513) to judge3 am: too few checklists (656) to judge4 am: too few checklists (1918) to judge5 am: too few checklists (16045) to judge6 am: 0.4% of 71991 checklists7 am: 0.7% of 159189 checklists8 am: 0.6% of 177206 checklists9 am: 0.5% of 165269 checklists10 am: 0.5% of 141029 checklists11 am: 0.4% of 115283 checklists12 pm: 0.4% of 96068 checklists1 pm: 0.4% of 89512 checklists2 pm: 0.4% of 86319 checklists3 pm: 0.4% of 82496 checklists4 pm: 0.4% of 71648 checklists5 pm: 0.3% of 52445 checklists6 pm: 0.1% of 40199 checklists7 pm: too few checklists (24246) to judge8 pm: too few checklists (7986) to judge9 pm: too few checklists (2004) to judge10 pm: too few checklists (888) to judge11 pm: too few checklists (450) 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
January0.8%0.7%0.7%0.8%
February0.7%0.6%0.4%0.5%
March0.4%0.5%0.5%0.4%
April0.4%0.3%0.4%0.5%
May0.5%0.4%0.2%0.1%
June0.1%0.1%0%0%
July0%0%0%0%
August0%0%0%0.1%
September0.1%0.1%0.2%0.6%
October1.2%1.6%1.9%1.8%
November1.3%0.9%0.9%0.9%
December0.7%0.8%0.7%0.7%

Neighboring states

  • Wyoming: arrives the second week of September, 2 weeks earlier than Colorado
  • New Mexico: arrives the second week of October, 2 weeks later than Colorado
  • Utah: arrives late September, in the same week than Colorado
  • Nebraska: arrives mid September, 1 week earlier than Colorado

Common questions

When do White-throated Sparrows arrive in Colorado?
White-throated Sparrows are winter birds in Colorado: they arrive in late September, peak in mid October (1.8% of checklists), and most are gone by the second week of May.
When do White-throated Sparrows leave Colorado?
Most White-throated Sparrows have left Colorado by the second week of May, when reports fall below half their usual rate.
When is the best time to see a White-throated Sparrow in Colorado?
The White-throated Sparrow is reported most often in mid October, on about 1.8% of Colorado checklists.
Where in Colorado are White-throated Sparrows seen most often?
By county, Baca County, San Miguel County, and Prowers County have the highest peak reporting rates for the White-throated Sparrow (counties with at least 200 checklists).