WhenToBird

Catharus guttatus · Turdidae

When Do Hermit Thrushes Arrive in Iowa?

Adult Hermit Thrush
Photo: Amber M. King, CC BY 4.0 via iNaturalist

Hermit Thrushes mostly pass through Iowa: they arrive in mid March, peak in the second week of April (6.2% of checklists), and most are gone by early May.

When to look

First arrivalsMar 15-21mid March
Common byMar 15-21mid March
PeakApr 8-14the second week of April
Most gone byMay 1-7early May

Best: the second week of April. First arrivals mid March; most are gone by early May. Peak: on about 6.2% of Iowa checklists.

  1. Janrare
  2. Febnot usually seen
  3. Maruncommon
  4. Aprpeak season
  5. Mayuncommon
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepuncommon
  10. Octpeak season
  11. Novuncommon
  12. Decrare

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

0%2%4%6%8%Jan 1-7: 0.2% of 5551 checklistsJan 8-14: 0.3% of 3498 checklistsJan 15-21: 0.2% of 3803 checklistsJan 22-31: 0.2% of 4807 checklistsFeb 1-7: 0.2% of 3613 checklistsFeb 8-14: 0.3% of 4173 checklistsFeb 15-21: 0.1% of 5796 checklistsFeb 22-28: 0.2% of 4394 checklistsMar 1-7: 0.1% of 5295 checklistsMar 8-14: 0.1% of 5679 checklistsMar 15-21: 0.2% of 5418 checklistsMar 22-31: 0.9% of 8613 checklistsApr 1-7: 4.0% of 6970 checklistsApr 8-14: 6.3% of 7511 checklistsApr 15-21: 7.9% of 8321 checklistsApr 22-30: 3.9% of 11976 checklistsMay 1-7: 0.4% of 11725 checklistsMay 8-14: 0.1% of 12626 checklistsMay 15-21: 0.1% of 9372 checklistsMay 22-31: 0% of 10330 checklistsJun 1-7: 0% of 5472 checklistsJun 8-14: 0% of 4568 checklistsJun 15-21: 0% of 3870 checklistsJun 22-30: 0% of 4780 checklistsJul 1-7: 0% of 4201 checklistsJul 8-14: 0% of 3605 checklistsJul 15-21: 0% of 3621 checklistsJul 22-31: 0% of 5093 checklistsAug 1-7: 0% of 3931 checklistsAug 8-14: 0% of 3488 checklistsAug 15-21: 0% of 3802 checklistsAug 22-31: 0% of 6293 checklistsSep 1-7: 0.1% of 5328 checklistsSep 8-14: 0.1% of 4622 checklistsSep 15-21: 0.1% of 4367 checklistsSep 22-30: 0.3% of 6086 checklistsOct 1-7: 3.2% of 4708 checklistsOct 8-14: 6.7% of 4791 checklistsOct 15-21: 6.8% of 4429 checklistsOct 22-31: 3.7% of 5633 checklistsNov 1-7: 1.3% of 4090 checklistsNov 8-14: 0.6% of 3416 checklistsNov 15-21: 0.3% of 3398 checklistsNov 22-30: 0.3% of 4679 checklistsDec 1-7: 0.1% of 3442 checklistsDec 8-14: 0.8% of 3322 checklistsDec 15-21: 0.7% of 4619 checklistsDec 22-31: 0.4% of 5113 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 Iowa 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 Iowa

Best counties

Share of checklists at the peak
  1. Montgomery CountyBest mid October · 13 checklists that week, 213 in all29%
  2. Howard CountyBest the second week of April · 15 checklists that week, 334 in all25%
  3. Mitchell CountyBest the second week of October · 11 checklists that week, 660 in all22%
  4. Bremer CountyBest mid October · 53 checklists that week, 3,421 in all19%
  5. Clay CountyBest the second week of October · 13 checklists that week, 844 in all18%
  6. Cedar CountyBest late October · 10 checklists that week, 765 in all18%

Best spots

Share of checklists at the peak
  1. Hartman Reserve Nature CenterBlack Hawk County, best the second week of April · 30 checklists that week, 711 in all48%
  2. Carr ParkStory County, best mid October · 21 checklists that week, 1,200 in all45%
  3. Hickory Hill ParkJohnson County, best the second week of April · 76 checklists that week, 2,281 in all38%
  4. Martin LakeBlack Hawk County, best the second week of April · 31 checklists that week, 523 in all35%
  5. Laverne Lake (southwest)Story County, best the second week of April · 26 checklists that week, 329 in all31%
  6. Greenwood ParkPolk County, best the second week of April · 28 checklists that week, 730 in all31%

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

Best time of day

In Iowa, the Hermit Thrush is most often listed on checklists started between 8 and 10 am (1.5% of those checklists).

0%0.5%1%1.5%2%12 am: too few checklists (96) to judge1 am: too few checklists (99) to judge2 am: too few checklists (67) to judge3 am: too few checklists (82) to judge4 am: too few checklists (201) to judge5 am: too few checklists (1888) to judge6 am: 1.0% of 11313 checklists7 am: 1.3% of 25717 checklists8 am: 1.5% of 29755 checklists9 am: 1.4% of 28897 checklists10 am: 1.3% of 26343 checklists11 am: 1.1% of 21210 checklists12 pm: 1.3% of 17662 checklists1 pm: 1.3% of 16595 checklists2 pm: 1.3% of 16405 checklists3 pm: 1.2% of 17030 checklists4 pm: 1.3% of 17378 checklists5 pm: 1.3% of 14251 checklists6 pm: 0.8% of 10349 checklists7 pm: 0.5% of 6233 checklists8 pm: too few checklists (2002) to judge9 pm: too few checklists (392) to judge10 pm: too few checklists (186) to judge11 pm: too few checklists (87) 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
January0.2%0.3%0.2%0.2%
February0.2%0.3%0.1%0.2%
March0.1%0.1%0.2%0.9%
April4.0%6.3%7.9%3.9%
May0.4%0.1%0.1%0%
June0%0%0%0%
July0%0%0%0%
August0%0%0%0%
September0.1%0.1%0.1%0.3%
October3.2%6.7%6.8%3.7%
November1.3%0.6%0.3%0.3%
December0.1%0.8%0.7%0.4%

Neighboring states

  • Missouri: arrives early October, 22 weeks earlier than Iowa
  • Wisconsin: arrives the second week of September, 23 weeks later than Iowa
  • Minnesota: arrives mid September, 24 weeks earlier than Iowa
  • Illinois: arrives mid September, 24 weeks earlier than Iowa

Common questions

When do Hermit Thrushes arrive in Iowa?
Hermit Thrushes mostly pass through Iowa: they arrive in mid March, peak in the second week of April (6.2% of checklists), and most are gone by early May.
When do Hermit Thrushes leave Iowa?
Most Hermit Thrushes have left Iowa by early May, when reports fall below half their usual rate.
When is the best time to see a Hermit Thrush in Iowa?
The Hermit Thrush is reported most often in the second week of April, on about 6.2% of Iowa checklists.
Where in Iowa are Hermit Thrushes seen most often?
By county, Montgomery County, Howard County, and Mitchell County have the highest peak reporting rates for the Hermit Thrush (counties with at least 200 checklists).