WhenToBird

Setophaga coronata · Parulidae

When Do Yellow-rumped Warblers Arrive in Colorado?

Adult Yellow-rumped Warbler
Photo: Jonathan Eisen, CC BY 4.0 via iNaturalist

Yellow-rumped Warblers reach Colorado in mid March, are common by the second week of April, peak in early May (32% of checklists), and most are gone by late October.

When to look

First arrivalsMar 15-21mid March
Common byApr 8-14the second week of April
PeakMay 1-7early May
Most gone byOct 22-31late October

Best: early May. First arrivals mid March; most are gone by late October. Peak: on about 32% of Colorado checklists.

  1. Janrare
  2. Febrare
  3. Marrare
  4. Aprpeak season
  5. Maypeak season
  6. Jununcommon
  7. Juluncommon
  8. Auguncommon
  9. Sepcommon
  10. Octcommon
  11. Novrare
  12. Decrare

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

0%10%20%30%40%Jan 1-7: 1.5% of 32254 checklistsJan 8-14: 1.5% of 23278 checklistsJan 15-21: 1.4% of 22933 checklistsJan 22-31: 1.4% of 30856 checklistsFeb 1-7: 1.2% of 21464 checklistsFeb 8-14: 1.2% of 22910 checklistsFeb 15-21: 0.8% of 28739 checklistsFeb 22-28: 1.1% of 21833 checklistsMar 1-7: 1.1% of 23066 checklistsMar 8-14: 1.1% of 23783 checklistsMar 15-21: 1.0% of 24797 checklistsMar 22-31: 1.2% of 38439 checklistsApr 1-7: 2.0% of 31676 checklistsApr 8-14: 4.6% of 35092 checklistsApr 15-21: 13% of 36778 checklistsApr 22-30: 27% of 50885 checklistsMay 1-7: 37% of 44186 checklistsMay 8-14: 32% of 49011 checklistsMay 15-21: 22% of 40784 checklistsMay 22-31: 13% of 53073 checklistsJun 1-7: 9.4% of 32432 checklistsJun 8-14: 9.3% of 29978 checklistsJun 15-21: 9.9% of 29457 checklistsJun 22-30: 10% of 36072 checklistsJul 1-7: 10% of 28857 checklistsJul 8-14: 10% of 27224 checklistsJul 15-21: 7.6% of 27629 checklistsJul 22-31: 6.5% of 37318 checklistsAug 1-7: 6.2% of 25893 checklistsAug 8-14: 6.8% of 24870 checklistsAug 15-21: 7.1% of 24035 checklistsAug 22-31: 9.1% of 35691 checklistsSep 1-7: 11% of 27068 checklistsSep 8-14: 14% of 26709 checklistsSep 15-21: 18% of 26098 checklistsSep 22-30: 24% of 31550 checklistsOct 1-7: 23% of 24110 checklistsOct 8-14: 20% of 23352 checklistsOct 15-21: 13% of 21895 checklistsOct 22-31: 6.6% of 28319 checklistsNov 1-7: 2.6% of 21698 checklistsNov 8-14: 1.7% of 21061 checklistsNov 15-21: 1.8% of 19855 checklistsNov 22-30: 1.6% of 25798 checklistsDec 1-7: 1.5% of 18626 checklistsDec 8-14: 1.5% of 19004 checklistsDec 15-21: 1.6% of 23103 checklistsDec 22-31: 1.1% 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. Pueblo CountyBest early May · 779 checklists that week, 26,547 in all55%
  2. La Plata CountyBest late September · 573 checklists that week, 21,744 in all54%
  3. Prowers CountyBest the second week of October · 177 checklists that week, 11,307 in all54%
  4. San Juan CountyBest late May · 103 checklists that week, 2,012 in all50%
  5. Washington CountyBest late September · 117 checklists that week, 2,511 in all49%
  6. Moffat CountyBest early October · 115 checklists that week, 5,700 in all48%

Best spots

Share of checklists at the peak
  1. Huck Finn PondLa Plata County, best late September · 52 checklists that week, 2,708 in all98%
  2. Pastorius Reservoir State Wildlife AreaLa Plata County, best early October · 65 checklists that week, 3,014 in all91%
  3. Skunk Creek (Bear Canyon Creek)Boulder County, best early May · 109 checklists that week, 627 in all91%
  4. San Juan National ForestMontezuma County, best late September · 28 checklists that week, 583 in all91%
  5. Long Lake Ranch Regional ParkJefferson County, best early May · 55 checklists that week, 867 in all90%
  6. Chico BasinPueblo County, best early May · 64 checklists that week, 963 in all88%

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

Best time of day

In Colorado, the Yellow-rumped Warbler is most often listed on checklists started between 6 and 8 am (12% of those checklists).

0%5%10%15%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: 13% of 71991 checklists7 am: 12% of 159189 checklists8 am: 12% of 177206 checklists9 am: 11% of 165269 checklists10 am: 9.8% of 141029 checklists11 am: 9.0% of 115283 checklists12 pm: 8.1% of 96068 checklists1 pm: 8.0% of 89512 checklists2 pm: 7.7% of 86319 checklists3 pm: 7.5% of 82496 checklists4 pm: 8.7% of 71648 checklists5 pm: 10% of 52445 checklists6 pm: 9.1% 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
January1.5%1.5%1.4%1.4%
February1.2%1.2%0.8%1.1%
March1.1%1.1%1.0%1.2%
April2.0%4.6%13%27%
May37%32%22%13%
June9.4%9.3%9.9%10%
July10%10%7.6%6.5%
August6.2%6.8%7.1%9.1%
September11%14%18%24%
October23%20%13%6.6%
November2.6%1.7%1.8%1.6%
December1.5%1.5%1.6%1.1%

Neighboring states

  • Wyoming: arrives the second week of April, 3 weeks later than Colorado
  • New Mexico: arrives the second week of September, 23 weeks later than Colorado
  • Utah: arrives mid September, 24 weeks earlier than Colorado
  • Nebraska: arrives early September, 22 weeks later than Colorado

Common questions

When do Yellow-rumped Warblers arrive in Colorado?
Yellow-rumped Warblers reach Colorado in mid March, are common by the second week of April, peak in early May (32% of checklists), and most are gone by late October.
When do Yellow-rumped Warblers leave Colorado?
Most Yellow-rumped Warblers have left Colorado by late October, when reports fall below half their usual rate. Stragglers are still reported until early February.
When is the best time to see a Yellow-rumped Warbler in Colorado?
The Yellow-rumped Warbler is reported most often in early May, on about 32% of Colorado checklists.
Where in Colorado are Yellow-rumped Warblers seen most often?
By county, Pueblo County, La Plata County, and Prowers County have the highest peak reporting rates for the Yellow-rumped Warbler (counties with at least 200 checklists).