WhenToBird

Setophaga coronata · Parulidae

When Do Yellow-rumped Warblers Arrive in Idaho?

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

Yellow-rumped Warblers are in Idaho all year, but most are here in fall: numbers build from the second week of September, peak in late September (31% of checklists), and fall back by the second week of October. In the quietest week (late March) they are still on about 5.0% of checklists.

When to look

Numbers buildSep 8-14the second week of September
PeakSep 22-30late September
Fall back byOct 8-14the second week of October
FewestMar 22-31late March

Best: late September. Here all year; numbers build from the second week of September and fall back by the second week of October. Peak: on about 31% of Idaho checklists.

  1. Januncommon
  2. Febuncommon
  3. Maruncommon
  4. Aprcommon
  5. Maycommon
  6. Juncommon
  7. Julcommon
  8. Augcommon
  9. Seppeak season
  10. Octpeak season
  11. Novuncommon
  12. Decuncommon

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

0%10%20%30%40%Jan 1-7: 7.3% of 9357 checklistsJan 8-14: 7.1% of 6408 checklistsJan 15-21: 6.4% of 6358 checklistsJan 22-31: 6.3% of 8601 checklistsFeb 1-7: 6.2% of 5611 checklistsFeb 8-14: 5.9% of 6090 checklistsFeb 15-21: 5.2% of 7973 checklistsFeb 22-28: 6.5% of 5866 checklistsMar 1-7: 6.3% of 6144 checklistsMar 8-14: 5.3% of 6456 checklistsMar 15-21: 5.1% of 6786 checklistsMar 22-31: 4.9% of 9539 checklistsApr 1-7: 5.0% of 7202 checklistsApr 8-14: 6.1% of 7608 checklistsApr 15-21: 9.9% of 8069 checklistsApr 22-30: 15% of 10973 checklistsMay 1-7: 20% of 9481 checklistsMay 8-14: 21% of 11318 checklistsMay 15-21: 20% of 9141 checklistsMay 22-31: 19% of 13984 checklistsJun 1-7: 15% of 8897 checklistsJun 8-14: 14% of 8504 checklistsJun 15-21: 14% of 8078 checklistsJun 22-30: 15% of 9665 checklistsJul 1-7: 14% of 7144 checklistsJul 8-14: 13% of 6557 checklistsJul 15-21: 11% of 6430 checklistsJul 22-31: 9.8% of 8696 checklistsAug 1-7: 7.2% of 5896 checklistsAug 8-14: 9.5% of 5643 checklistsAug 15-21: 11% of 6151 checklistsAug 22-31: 12% of 7863 checklistsSep 1-7: 17% of 5769 checklistsSep 8-14: 23% of 5646 checklistsSep 15-21: 28% of 5460 checklistsSep 22-30: 32% of 6363 checklistsOct 1-7: 33% of 4980 checklistsOct 8-14: 24% of 5096 checklistsOct 15-21: 17% of 4878 checklistsOct 22-31: 12% of 6426 checklistsNov 1-7: 9.4% of 4822 checklistsNov 8-14: 10% of 4999 checklistsNov 15-21: 11% of 4601 checklistsNov 22-30: 11% of 6027 checklistsDec 1-7: 11% of 4180 checklistsDec 8-14: 11% of 4775 checklistsDec 15-21: 10% of 6522 checklistsDec 22-31: 9.7% of 7792 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 Idaho 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 Idaho

Best counties

Share of checklists at the peak
  1. Jefferson CountyBest late September · 106 checklists that week, 5,319 in all58%
  2. Minidoka CountyBest early May · 46 checklists that week, 1,365 in all46%
  3. Bonner CountyBest the second week of May · 304 checklists that week, 10,972 in all46%
  4. Teton CountyBest mid May · 166 checklists that week, 6,406 in all45%
  5. Custer CountyBest mid May · 92 checklists that week, 3,853 in all45%
  6. Cassia CountyBest mid September · 205 checklists that week, 9,223 in all45%

Best spots

Share of checklists at the peak
  1. Wilson Springs Access SiteCanyon County, best late November · 29 checklists that week, 1,000 in all84%
  2. Sawtooth National ForestCassia County, best late May · 47 checklists that week, 885 in all83%
  3. Kathryn Albertson ParkAda County, best the second week of April · 75 checklists that week, 3,927 in all80%
  4. Arboretum & Botanical GardenLatah County, best late September · 58 checklists that week, 2,190 in all80%
  5. Aldape SummitAda County, best late May · 30 checklists that week, 210 in all77%

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

Best time of day

In Idaho, the Yellow-rumped Warbler is most often listed on checklists started between 6 and 8 am (18% of those checklists).

0%5%10%15%20%12 am: too few checklists (180) to judge1 am: too few checklists (176) to judge2 am: too few checklists (169) to judge3 am: too few checklists (164) to judge4 am: too few checklists (450) to judge5 am: too few checklists (2270) to judge6 am: 19% of 9122 checklists7 am: 17% of 22204 checklists8 am: 17% of 38672 checklists9 am: 15% of 38930 checklists10 am: 14% of 37338 checklists11 am: 12% of 33508 checklists12 pm: 11% of 28544 checklists1 pm: 11% of 25774 checklists2 pm: 9.8% of 24296 checklists3 pm: 9.2% of 21784 checklists4 pm: 9.4% of 19051 checklists5 pm: 9.7% of 14150 checklists6 pm: 10% of 10014 checklists7 pm: 9.2% of 7495 checklists8 pm: too few checklists (4352) to judge9 pm: too few checklists (1449) to judge10 pm: too few checklists (525) to judge11 pm: too few checklists (208) 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
January7.3%7.1%6.4%6.3%
February6.2%5.9%5.2%6.5%
March6.3%5.3%5.1%4.9%
April5.0%6.1%9.9%15%
May20%21%20%19%
June15%14%14%15%
July14%13%11%9.8%
August7.2%9.5%11%12%
September17%23%28%32%
October33%24%17%12%
November9.4%10%11%11%
December11%11%10%9.7%

Neighboring states

  • Montana: arrives mid April, 19 weeks earlier than Idaho
  • Utah: arrives mid September, 1 week later than Idaho
  • Oregon: arrives late March, 22 weeks earlier than Idaho
  • Washington: arrives the second week of April, 20 weeks earlier than Idaho

Common questions

When do Yellow-rumped Warblers arrive in Idaho?
Yellow-rumped Warblers are in Idaho all year, but most are here in fall: numbers build from the second week of September, peak in late September (31% of checklists), and fall back by the second week of October. In the quietest week (late March) they are still on about 5.0% of checklists.
When do Yellow-rumped Warblers leave Idaho?
Yellow-rumped Warblers never fully leave Idaho: numbers fall back below half their usual rate by the second week of October, but some are still reported in every week, about 5.0% of checklists at the low.
When is the best time to see a Yellow-rumped Warbler in Idaho?
The Yellow-rumped Warbler is reported most often in late September, on about 31% of Idaho checklists.
Where in Idaho are Yellow-rumped Warblers seen most often?
By county, Jefferson County, Minidoka County, and Bonner County have the highest peak reporting rates for the Yellow-rumped Warbler (counties with at least 200 checklists).