WhenToBird

Turdus migratorius · Turdidae

When Do American Robins Arrive in Colorado?

Adult male American Robin
Photo: northerly, CC BY 4.0 via iNaturalist

American Robins are in Colorado all year, but most are here in spring: numbers build from mid March, peak in mid May (62% of checklists), and fall back by mid July. In the quietest week (the second week of February) they are still on about 23% of checklists.

When to look

Numbers buildMar 15-21mid March
PeakMay 15-21mid May
Fall back byJul 15-21mid July
FewestFeb 8-14the second week of February

Best: mid May. Here all year; numbers build from mid March and fall back by mid July. Peak: on about 62% of Colorado checklists.

  1. Jancommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julpeak season
  8. Augcommon
  9. Sepcommon
  10. Octcommon
  11. Novcommon
  12. Deccommon

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

0%20%40%60%80%Jan 1-7: 24% of 32254 checklistsJan 8-14: 25% of 23278 checklistsJan 15-21: 25% of 22933 checklistsJan 22-31: 24% of 30856 checklistsFeb 1-7: 24% of 21464 checklistsFeb 8-14: 22% of 22910 checklistsFeb 15-21: 23% of 28739 checklistsFeb 22-28: 27% of 21833 checklistsMar 1-7: 34% of 23066 checklistsMar 8-14: 40% of 23783 checklistsMar 15-21: 47% of 24797 checklistsMar 22-31: 52% of 38439 checklistsApr 1-7: 52% of 31676 checklistsApr 8-14: 53% of 35092 checklistsApr 15-21: 54% of 36778 checklistsApr 22-30: 59% of 50885 checklistsMay 1-7: 61% of 44186 checklistsMay 8-14: 62% of 49011 checklistsMay 15-21: 62% of 40784 checklistsMay 22-31: 62% of 53073 checklistsJun 1-7: 62% of 32432 checklistsJun 8-14: 61% of 29978 checklistsJun 15-21: 61% of 29457 checklistsJun 22-30: 60% of 36072 checklistsJul 1-7: 58% of 28857 checklistsJul 8-14: 53% of 27224 checklistsJul 15-21: 47% of 27629 checklistsJul 22-31: 41% of 37318 checklistsAug 1-7: 35% of 25893 checklistsAug 8-14: 30% of 24870 checklistsAug 15-21: 26% of 24035 checklistsAug 22-31: 24% of 35691 checklistsSep 1-7: 26% of 27068 checklistsSep 8-14: 29% of 26709 checklistsSep 15-21: 32% of 26098 checklistsSep 22-30: 36% of 31550 checklistsOct 1-7: 37% of 24110 checklistsOct 8-14: 35% of 23352 checklistsOct 15-21: 34% of 21895 checklistsOct 22-31: 31% of 28319 checklistsNov 1-7: 27% of 21698 checklistsNov 8-14: 26% of 21061 checklistsNov 15-21: 28% of 19855 checklistsNov 22-30: 26% of 25798 checklistsDec 1-7: 26% of 18626 checklistsDec 8-14: 27% of 19004 checklistsDec 15-21: 29% of 23103 checklistsDec 22-31: 26% 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. Broomfield CountyBest early June · 212 checklists that week, 16,139 in all79%
  2. San Miguel CountyBest late June · 215 checklists that week, 8,094 in all75%
  3. Sedgwick CountyBest early July · 26 checklists that week, 1,168 in all75%
  4. Phillips CountyBest early June · 21 checklists that week, 1,052 in all73%
  5. Mineral CountyBest mid June · 105 checklists that week, 1,750 in all73%
  6. Eagle CountyBest late May · 670 checklists that week, 15,893 in all71%

Best spots

Share of checklists at the peak
  1. Elaine T Valente Open SpaceAdams County, best late April · 22 checklists that week, 388 in all100%
  2. Sheldon LakeLarimer County, best the second week of June · 26 checklists that week, 2,868 in all99%
  3. Prospect Lake (south)El Paso County, best mid May · 34 checklists that week, 472 in all99%
  4. Chatfield Lake (Fairview Reservoir Number 2)Jefferson County, best mid June · 28 checklists that week, 1,041 in all99%

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

Best time of day

In Colorado, the American Robin is most often listed on checklists started between 6 and 8 am (54% of those checklists).

0%20%40%60%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: 59% of 71991 checklists7 am: 52% of 159189 checklists8 am: 48% of 177206 checklists9 am: 43% of 165269 checklists10 am: 37% of 141029 checklists11 am: 32% of 115283 checklists12 pm: 30% of 96068 checklists1 pm: 31% of 89512 checklists2 pm: 32% of 86319 checklists3 pm: 36% of 82496 checklists4 pm: 39% of 71648 checklists5 pm: 45% of 52445 checklists6 pm: 48% 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
January24%25%25%24%
February24%22%23%27%
March34%40%47%52%
April52%53%54%59%
May61%62%62%62%
June62%61%61%60%
July58%53%47%41%
August35%30%26%24%
September26%29%32%36%
October37%35%34%31%
November27%26%28%26%
December26%27%29%26%

Neighboring states

  • Wyoming: arrives late March, 1 week later than Colorado
  • New Mexico: year-round, peaks late October
  • Utah: arrives mid March, in the same week than Colorado
  • Nebraska: arrives early March, 2 weeks earlier than Colorado

Common questions

When do American Robins arrive in Colorado?
American Robins are in Colorado all year, but most are here in spring: numbers build from mid March, peak in mid May (62% of checklists), and fall back by mid July. In the quietest week (the second week of February) they are still on about 23% of checklists.
When do American Robins leave Colorado?
American Robins never fully leave Colorado: numbers fall back below half their usual rate by mid July, but some are still reported in every week, about 23% of checklists at the low.
When is the best time to see a American Robin in Colorado?
The American Robin is reported most often in mid May, on about 62% of Colorado checklists.
Where in Colorado are American Robins seen most often?
By county, Broomfield County, San Miguel County, and Sedgwick County have the highest peak reporting rates for the American Robin (counties with at least 200 checklists).