WhenToBird

Anas platyrhynchos · Anatidae

When Do Mallards Arrive in Iowa?

Adult male Mallard
Photo: euqirneto, CC BY 4.0 via iNaturalist

Mallards are in Iowa all year, but most are here in spring: numbers build from late February, peak in the second week of March (41% of checklists), and fall back by late April. In the quietest week (early July) they are still on about 12% of checklists.

When to look

Numbers buildFeb 22-28late February
PeakMar 8-14the second week of March
Fall back byApr 22-30late April
FewestJul 1-7early July

Best: the second week of March. Here all year; numbers build from late February and fall back by late April. Peak: on about 41% of Iowa checklists.

  1. Jancommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Maycommon
  6. Juncommon
  7. Juluncommon
  8. Augcommon
  9. Sepcommon
  10. Octcommon
  11. Novpeak season
  12. Decpeak season

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

0%20%40%60%Jan 1-7: 22% of 5551 checklistsJan 8-14: 19% of 3498 checklistsJan 15-21: 15% of 3803 checklistsJan 22-31: 18% of 4807 checklistsFeb 1-7: 19% of 3613 checklistsFeb 8-14: 16% of 4173 checklistsFeb 15-21: 18% of 5796 checklistsFeb 22-28: 31% of 4394 checklistsMar 1-7: 39% of 5295 checklistsMar 8-14: 41% of 5679 checklistsMar 15-21: 42% of 5418 checklistsMar 22-31: 39% of 8613 checklistsApr 1-7: 36% of 6970 checklistsApr 8-14: 33% of 7511 checklistsApr 15-21: 33% of 8321 checklistsApr 22-30: 30% of 11976 checklistsMay 1-7: 25% of 11725 checklistsMay 8-14: 22% of 12626 checklistsMay 15-21: 22% of 9372 checklistsMay 22-31: 20% of 10330 checklistsJun 1-7: 17% of 5472 checklistsJun 8-14: 15% of 4568 checklistsJun 15-21: 14% of 3870 checklistsJun 22-30: 12% of 4780 checklistsJul 1-7: 11% of 4201 checklistsJul 8-14: 12% of 3605 checklistsJul 15-21: 13% of 3621 checklistsJul 22-31: 16% of 5093 checklistsAug 1-7: 16% of 3931 checklistsAug 8-14: 18% of 3488 checklistsAug 15-21: 17% of 3802 checklistsAug 22-31: 15% of 6293 checklistsSep 1-7: 14% of 5328 checklistsSep 8-14: 15% of 4622 checklistsSep 15-21: 17% of 4367 checklistsSep 22-30: 18% of 6086 checklistsOct 1-7: 18% of 4708 checklistsOct 8-14: 19% of 4791 checklistsOct 15-21: 22% of 4429 checklistsOct 22-31: 27% of 5633 checklistsNov 1-7: 30% of 4090 checklistsNov 8-14: 32% of 3416 checklistsNov 15-21: 30% of 3398 checklistsNov 22-30: 33% of 4679 checklistsDec 1-7: 33% of 3442 checklistsDec 8-14: 27% of 3322 checklistsDec 15-21: 23% of 4619 checklistsDec 22-31: 23% 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. Hancock CountyBest mid March · 11 checklists that week, 449 in all74%
  2. Louisa CountyBest the second week of March · 73 checklists that week, 1,639 in all74%
  3. Harrison CountyBest mid November · 24 checklists that week, 1,977 in all72%
  4. Sac CountyBest the second week of March · 23 checklists that week, 1,085 in all72%
  5. Kossuth CountyBest the second week of March · 16 checklists that week, 628 in all71%
  6. Buena Vista CountyBest late March · 91 checklists that week, 2,846 in all71%

Best spots

Share of checklists at the peak
  1. Cedar Lake ParkLinn County, best late July · 20 checklists that week, 1,387 in all100%
  2. Saylorville Recreation AreaPolk County, best late January · 92 checklists that week, 1,723 in all98%
  3. Credit Isand ParkScott County, best mid February · 27 checklists that week, 777 in all98%
  4. West LakeJohnson County, best late October · 29 checklists that week, 307 in all98%
  5. Polk City RefugePolk County, best mid November · 29 checklists that week, 705 in all98%
  6. Central ParkJohnson County, best early February · 39 checklists that week, 700 in all97%

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

Best time of day

In Iowa, the Mallard is most often listed on checklists started between 5 and 7 pm (27% of those checklists).

0%10%20%30%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: 24% of 11313 checklists7 am: 22% of 25717 checklists8 am: 23% of 29755 checklists9 am: 23% of 28897 checklists10 am: 23% of 26343 checklists11 am: 23% of 21210 checklists12 pm: 24% of 17662 checklists1 pm: 23% of 16595 checklists2 pm: 24% of 16405 checklists3 pm: 25% of 17030 checklists4 pm: 26% of 17378 checklists5 pm: 27% of 14251 checklists6 pm: 27% of 10349 checklists7 pm: 22% 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
January22%19%15%18%
February19%16%18%31%
March39%41%42%39%
April36%33%33%30%
May25%22%22%20%
June17%15%14%12%
July11%12%13%16%
August16%18%17%15%
September14%15%17%18%
October18%19%22%27%
November30%32%30%33%
December33%27%23%23%

Neighboring states

  • Missouri: year-round, peaks early March
  • Wisconsin: arrives early March, 1 week later than Iowa
  • Minnesota: arrives the second week of March, 2 weeks later than Iowa
  • Illinois: year-round, peaks late March

Common questions

When do Mallards arrive in Iowa?
Mallards are in Iowa all year, but most are here in spring: numbers build from late February, peak in the second week of March (41% of checklists), and fall back by late April. In the quietest week (early July) they are still on about 12% of checklists.
When do Mallards leave Iowa?
Mallards never fully leave Iowa: numbers fall back below half their usual rate by late April, but some are still reported in every week, about 12% of checklists at the low.
When is the best time to see a Mallard in Iowa?
The Mallard is reported most often in the second week of March, on about 41% of Iowa checklists.
Where in Iowa are Mallards seen most often?
By county, Hancock County, Louisa County, and Harrison County have the highest peak reporting rates for the Mallard (counties with at least 200 checklists).