WhenToBird

Passer domesticus · Passeridae

When Do House Sparrows Arrive in Colorado?

Adult male House Sparrow
Photo: Esteban Poveda, CC BY 4.0 via iNaturalist

The House Sparrow is in Colorado all year. It turns up on about 18% of checklists at its peak (the second week of May) and on 10% in its quietest week (the second week of September).

When to look

PresentAll year
Peak weekMay 8-14the second week of May
Quietest weekSep 8-14the second week of September

Best: the second week of May. Here all year. Peak: on about 18% of Colorado checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julpeak season
  8. Augpeak season
  9. Sepcommon
  10. Octcommon
  11. Novpeak season
  12. Decpeak season

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

0%5%10%15%20%Jan 1-7: 14% of 32254 checklistsJan 8-14: 14% of 23278 checklistsJan 15-21: 15% of 22933 checklistsJan 22-31: 15% of 30856 checklistsFeb 1-7: 15% of 21464 checklistsFeb 8-14: 16% of 22910 checklistsFeb 15-21: 17% of 28739 checklistsFeb 22-28: 16% of 21833 checklistsMar 1-7: 17% of 23066 checklistsMar 8-14: 16% of 23783 checklistsMar 15-21: 16% of 24797 checklistsMar 22-31: 15% of 38439 checklistsApr 1-7: 15% of 31676 checklistsApr 8-14: 15% of 35092 checklistsApr 15-21: 14% of 36778 checklistsApr 22-30: 16% of 50885 checklistsMay 1-7: 18% of 44186 checklistsMay 8-14: 18% of 49011 checklistsMay 15-21: 18% of 40784 checklistsMay 22-31: 17% of 53073 checklistsJun 1-7: 16% of 32432 checklistsJun 8-14: 15% of 29978 checklistsJun 15-21: 15% of 29457 checklistsJun 22-30: 15% of 36072 checklistsJul 1-7: 15% of 28857 checklistsJul 8-14: 15% of 27224 checklistsJul 15-21: 15% of 27629 checklistsJul 22-31: 16% of 37318 checklistsAug 1-7: 16% of 25893 checklistsAug 8-14: 14% of 24870 checklistsAug 15-21: 13% of 24035 checklistsAug 22-31: 12% of 35691 checklistsSep 1-7: 10% of 27068 checklistsSep 8-14: 9.7% of 26709 checklistsSep 15-21: 10% of 26098 checklistsSep 22-30: 11% of 31550 checklistsOct 1-7: 12% of 24110 checklistsOct 8-14: 12% of 23352 checklistsOct 15-21: 13% of 21895 checklistsOct 22-31: 13% of 28319 checklistsNov 1-7: 13% of 21698 checklistsNov 8-14: 13% of 21061 checklistsNov 15-21: 14% of 19855 checklistsNov 22-30: 14% of 25798 checklistsDec 1-7: 14% of 18626 checklistsDec 8-14: 15% of 19004 checklistsDec 15-21: 16% of 23103 checklistsDec 22-31: 15% 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. San Juan CountyBest mid March · 13 checklists that week, 2,012 in all76%
  2. Prowers CountyBest early August · 113 checklists that week, 11,307 in all70%
  3. Sedgwick CountyBest the second week of July · 14 checklists that week, 1,168 in all66%
  4. Moffat CountyBest late December · 64 checklists that week, 5,700 in all62%
  5. Dolores CountyBest the second week of December · 21 checklists that week, 2,000 in all61%
  6. San Miguel CountyBest early February · 121 checklists that week, 8,094 in all57%

Best spots

Share of checklists at the peak
  1. NorwoodSan Miguel County, best late November · 29 checklists that week, 1,247 in all100%
  2. EadsKiowa County, best the second week of May · 26 checklists that week, 225 in all93%
  3. Last ChanceWashington County, best early May · 42 checklists that week, 368 in all91%
  4. Denny Lake ParkMontezuma County, best mid May · 33 checklists that week, 834 in all89%

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

Best time of day

In Colorado, the House Sparrow is most often listed on checklists started between 6 and 8 am (19% of those checklists).

0%5%10%15%20%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: 19% of 71991 checklists7 am: 19% of 159189 checklists8 am: 18% of 177206 checklists9 am: 16% of 165269 checklists10 am: 14% of 141029 checklists11 am: 13% of 115283 checklists12 pm: 12% of 96068 checklists1 pm: 12% of 89512 checklists2 pm: 12% of 86319 checklists3 pm: 13% of 82496 checklists4 pm: 13% of 71648 checklists5 pm: 13% of 52445 checklists6 pm: 13% 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
January14%14%15%15%
February15%16%17%16%
March17%16%16%15%
April15%15%14%16%
May18%18%18%17%
June16%15%15%15%
July15%15%15%16%
August16%14%13%12%
September10%9.7%10%11%
October12%12%13%13%
November13%13%14%14%
December14%15%16%15%

Neighboring states

  • Wyoming: all year, most in winter, peaks mid February
  • New Mexico: year-round, peaks the second week of May
  • Utah: year-round, peaks mid February
  • Nebraska: year-round, peaks mid February

Common questions

When do House Sparrows arrive in Colorado?
The House Sparrow is in Colorado all year. It turns up on about 18% of checklists at its peak (the second week of May) and on 10% in its quietest week (the second week of September).
When do House Sparrows leave Colorado?
The House Sparrow does not leave Colorado: it is reported all year, from 10% of checklists in the second week of September to 18% in the second week of May.
When is the best time to see a House Sparrow in Colorado?
The House Sparrow is reported most often in the second week of May, on about 18% of Colorado checklists.
Where in Colorado are House Sparrows seen most often?
By county, San Juan County, Prowers County, and Sedgwick County have the highest peak reporting rates for the House Sparrow (counties with at least 200 checklists).