WhenToBird

Passerella iliaca · Passerellidae

When Do Fox Sparrows Arrive in Iowa?

Adult Fox Sparrow
Photo: Kevin Krebs, CC BY 4.0 via iNaturalist

Fox Sparrows are winter birds in Iowa: they arrive in early October, peak in late October (11% of checklists), and most are gone by mid December.

When to look

First arrivalsOct 1-7early October
Common byOct 1-7early October
PeakOct 22-31late October
Most gone byDec 15-21mid December

Best: late October. First arrivals early October; most are gone by mid December. Peak: on about 11% of Iowa checklists.

  1. Janrare
  2. Febrare
  3. Marpeak season
  4. Aprpeak season
  5. Maynot usually seen
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Seprare
  10. Octpeak season
  11. Novpeak season
  12. Decrare

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

0%5%10%15%Jan 1-7: 0.8% of 5551 checklistsJan 8-14: 0.5% of 3498 checklistsJan 15-21: 0.9% of 3803 checklistsJan 22-31: 0.7% of 4807 checklistsFeb 1-7: 0.5% of 3613 checklistsFeb 8-14: 0.5% of 4173 checklistsFeb 15-21: 0.7% of 5796 checklistsFeb 22-28: 0.6% of 4394 checklistsMar 1-7: 0.9% of 5295 checklistsMar 8-14: 3.0% of 5679 checklistsMar 15-21: 5.1% of 5418 checklistsMar 22-31: 9.2% of 8613 checklistsApr 1-7: 12% of 6970 checklistsApr 8-14: 5.5% of 7511 checklistsApr 15-21: 3.8% of 8321 checklistsApr 22-30: 0.4% of 11976 checklistsMay 1-7: 0.1% of 11725 checklistsMay 8-14: 0% of 12626 checklistsMay 15-21: 0% 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% of 5328 checklistsSep 8-14: 0% of 4622 checklistsSep 15-21: 0.1% of 4367 checklistsSep 22-30: 0.5% of 6086 checklistsOct 1-7: 2.5% of 4708 checklistsOct 8-14: 5.7% of 4791 checklistsOct 15-21: 10% of 4429 checklistsOct 22-31: 11% of 5633 checklistsNov 1-7: 11% of 4090 checklistsNov 8-14: 6.1% of 3416 checklistsNov 15-21: 3.8% of 3398 checklistsNov 22-30: 1.7% of 4679 checklistsDec 1-7: 0.6% of 3442 checklistsDec 8-14: 1.1% of 3322 checklistsDec 15-21: 1.2% of 4619 checklistsDec 22-31: 1.0% 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 all63%
  2. Sioux CountyBest mid October · 19 checklists that week, 1,159 in all36%
  3. Franklin CountyBest late October · 13 checklists that week, 331 in all35%
  4. Mitchell CountyBest mid October · 12 checklists that week, 660 in all34%
  5. Jones CountyBest late March · 10 checklists that week, 541 in all28%
  6. Lyon CountyBest early April · 15 checklists that week, 498 in all25%

Best spots

Share of checklists at the peak
  1. Tedesco Environmental Learning Corridor (TELC)Story County, best late October · 31 checklists that week, 969 in all59%
  2. Laverne Lake (southwest)Story County, best late March · 37 checklists that week, 329 in all56%
  3. Hartman Reserve Nature CenterBlack Hawk County, best early April · 23 checklists that week, 711 in all44%
  4. Cedar River Crossing AdditionJohnson County, best mid October · 34 checklists that week, 564 in all42%
  5. Carr ParkStory County, best mid October · 21 checklists that week, 1,200 in all41%
  6. Saylorville Recreation Area (Camp Dodge)Polk County, best mid October · 38 checklists that week, 690 in all37%

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

Best time of day

In Iowa, the Fox Sparrow is most often listed on checklists started between 8 and 10 am (2.6% of those checklists).

0%1%2%3%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: 1.4% of 11313 checklists7 am: 2.3% of 25717 checklists8 am: 2.6% of 29755 checklists9 am: 2.6% of 28897 checklists10 am: 2.2% of 26343 checklists11 am: 2.2% of 21210 checklists12 pm: 2.1% of 17662 checklists1 pm: 2.0% of 16595 checklists2 pm: 2.0% of 16405 checklists3 pm: 2.2% of 17030 checklists4 pm: 2.1% of 17378 checklists5 pm: 2.6% of 14251 checklists6 pm: 1.8% of 10349 checklists7 pm: 0.7% 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
January0.8%0.5%0.9%0.7%
February0.5%0.5%0.7%0.6%
March0.9%3.0%5.1%9.2%
April12%5.5%3.8%0.4%
May0.1%0%0%0%
June0%0%0%0%
July0%0%0%0%
August0%0%0%0%
September0%0%0.1%0.5%
October2.5%5.7%10%11%
November11%6.1%3.8%1.7%
December0.6%1.1%1.2%1.0%

Neighboring states

  • Missouri: arrives mid October, 2 weeks later than Iowa
  • Wisconsin: arrives early March, 20 weeks later than Iowa
  • Minnesota: arrives the second week of March, 21 weeks later than Iowa
  • Illinois: arrives early October, in the same week than Iowa

Common questions

When do Fox Sparrows arrive in Iowa?
Fox Sparrows are winter birds in Iowa: they arrive in early October, peak in late October (11% of checklists), and most are gone by mid December.
When do Fox Sparrows leave Iowa?
Most Fox Sparrows have left Iowa by mid December, when reports fall below half their usual rate.
When is the best time to see a Fox Sparrow in Iowa?
The Fox Sparrow is reported most often in late October, on about 11% of Iowa checklists.
Where in Iowa are Fox Sparrows seen most often?
By county, Montgomery County, Sioux County, and Franklin County have the highest peak reporting rates for the Fox Sparrow (counties with at least 200 checklists).