Iowa / IA-04
Iowa District 4
Score
Irregularity score 35 CompactLess compact than 30% of other congressional districts.
301st least compact of 429 nationally, 2nd of 4 in Iowa.
A score describes shape, not intent. Coastlines, rivers and the Voting Rights Act can all make a district irregular. How scores work
The three measures
- Polsby-Popper
- 0.29at least as compact as 64% of districts on this measure
Area compared with perimeter. Low for jagged or snaking edges.
- Reock
- 0.66at least as compact as 87% of districts on this measure
Area compared with the smallest circle around the district, counting only land. Low for stretched shapes.
- Convex hull
- 0.76at least as compact as 45% of districts on this measure
Area compared with a rubber band stretched around the district, counting only land. Low for bites and tentacles.
Each measure runs from 0 to 1, where 1 is a perfect circle or a shape with no dents.
The state's edge
51% of this district's border is the state's edge: a coastline, a national border or a state line. Mapmakers don't choose those lines. A ragged one, like a coastline or a river, lowers Polsby-Popper. Reock and convex hull count only the state's own land, so water and neighboring states don't count against them. More on the state's edge
Cities and towns
The largest places with people in this district, from the 2020 Census. A place split between districts shows how many of its residents live in this one.
- Sioux City cityall 85,797 residents
- Ames cityall 66,427 residents
- Council Bluffs cityall 62,799 residents
- Marshalltown cityall 27,591 residents
- Fort Dodge cityall 24,871 residents
- Boone cityall 12,460 residents
- Spencer cityall 11,325 residents
- Storm Lake cityall 11,269 residents
- Le Mars cityall 10,571 residents
- Carroll cityall 10,321 residents
And 368 smaller places. 21% of this district's people live outside any city, town or named community. How places are counted
ZIP codes
392 ZIP codes have residents in this district. 67 of them are split with other districts. A percentage is the share of that ZIP code's 2020 residents who live here.
Show all 392 ZIP codes
- 50002 (1%)
- 50005
- 50006 (12%)
- 50010
- 50012
- 50013
- 50014
- 50020 (2%)
- 50022 (1%)
- 50025 (99%)
- 50028 (1%)
- 50031
- 50034
- 50036
- 50039 (5%)
- 50040
- 50041
- 50042
- 50046 (82%)
- 50050 (1%)
- 50051
- 50055 (78%)
- 50056
- 50058 (86%)
- 50064 (15%)
- 50071
- 50075
- 50076
- 50078
- 50101
- 50105
- 50106 (84%)
- 50107 (4%)
- 50110
- 50117
- 50120
- 50124 (99%)
- 50126 (3%)
- 50130
- 50132
- 50134
- 50141 (83%)
- 50142
- 50148
- 50152
- 50154 (96%)
- 50156 (87%)
- 50158 (99%)
- 50161 (75%)
- 50162 (99%)
- 50201
- 50206 (14%)
- 50212
- 50217 (12%)
- 50220 (5%)
- 50223
- 50226 (1%)
- 50227
- 50230 (20%)
- 50231
- 50234 (91%)
- 50235 (5%)
- 50236
- 50239
- 50243 (52%)
- 50244 (91%)
- 50246
- 50247
- 50248
- 50249
- 50258 (8%)
- 50271
- 50276 (35%)
- 50278
- 50420
- 50421
- 50423
- 50424
- 50427
- 50430
- 50431
- 50432
- 50433 (10%)
- 50436
- 50438
- 50439
- 50441
- 50446 (8%)
- 50447
- 50449 (99%)
- 50450 (94%)
- 50451
- 50452
- 50453
- 50457 (27%)
- 50459 (1%)
- 50465
- 50470
- 50473
- 50475 (92%)
- 50478
- 50479 (10%)
- 50480
- 50482 (8%)
- 50483
- 50484
- 50501
- 50510
- 50511
- 50514
- 50515
- 50516
- 50517
- 50518
- 50519
- 50520
- 50521
- 50522
- 50523
- 50524
- 50525
- 50527
- 50528
- 50529
- 50530
- 50531
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- 50533
- 50535
- 50536
- 50538
- 50539
- 50540
- 50541
- 50542
- 50543
- 50544
- 50545
- 50546
- 50548
- 50551
- 50552
- 50554
- 50556
- 50557
- 50558
- 50559
- 50560
- 50561
- 50562
- 50563
- 50565
- 50566
- 50567
- 50568
- 50569
- 50570
- 50571
- 50573
- 50574
- 50575
- 50576
- 50577
- 50578
- 50579
- 50581
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- 50583
- 50585
- 50586
- 50588
- 50590
- 50591
- 50592
- 50593
- 50594
- 50595
- 50597
- 50598
- 50599
- 50601 (13%)
- 50605 (37%)
- 50609 (21%)
- 50621 (4%)
- 50625 (5%)
- 50632 (10%)
- 50633
- 50635 (2%)
- 51001 (86%)
- 51002
- 51003
- 51004
- 51005
- 51006
- 51007
- 51008
- 51009
- 51010
- 51011
- 51012
- 51014
- 51015
- 51016
- 51018
- 51019
- 51020
- 51022
- 51023 (94%)
- 51024
- 51025
- 51026
- 51027
- 51028
- 51029
- 51030
- 51031
- 51033
- 51034
- 51035
- 51036
- 51037
- 51038
- 51039
- 51040
- 51041
- 51044
- 51045
- 51046
- 51047
- 51048
- 51049
- 51050
- 51051
- 51052
- 51053
- 51054
- 51055
- 51056
- 51058
- 51060
- 51061
- 51062
- 51063
- 51101
- 51103
- 51104
- 51105
- 51106
- 51108
- 51109
- 51111
- 51201
- 51230
- 51231
- 51232
- 51234
- 51235
- 51237
- 51238
- 51239
- 51240
- 51241
- 51242
- 51243
- 51244
- 51245
- 51246
- 51247
- 51248
- 51249
- 51250
- 51301
- 51331
- 51333
- 51334
- 51338
- 51340
- 51341
- 51342
- 51343
- 51345
- 51346
- 51347
- 51350
- 51351
- 51354
- 51355
- 51357
- 51358
- 51360 (99%)
- 51363
- 51364
- 51365
- 51366
- 51401
- 51430
- 51431
- 51432
- 51433
- 51436
- 51439
- 51440
- 51441
- 51442
- 51443
- 51444
- 51445
- 51446
- 51447
- 51448
- 51449
- 51450
- 51451
- 51452
- 51453
- 51454
- 51455
- 51458
- 51459
- 51460
- 51461
- 51462 (1%)
- 51463
- 51465
- 51466
- 51467
- 51501
- 51503
- 51510
- 51520
- 51521
- 51523
- 51525
- 51526
- 51527
- 51528
- 51529
- 51530
- 51531
- 51532 (3%)
- 51533 (74%)
- 51534
- 51535 (16%)
- 51536
- 51537
- 51540
- 51541 (91%)
- 51542
- 51543
- 51544 (10%)
- 51545
- 51546
- 51548
- 51549
- 51550
- 51551
- 51552 (25%)
- 51553
- 51554
- 51555
- 51556
- 51557 (96%)
- 51558
- 51559
- 51560
- 51561
- 51562
- 51563
- 51564
- 51565
- 51566 (1%)
- 51570
- 51571
- 51572
- 51575
- 51576
- 51577 (99%)
- 51578
- 51579
- 51601 (3%)
- 51639
- 51640
- 51645 (98%)
- 51647 (21%)
- 51648
- 51649
- 51650
- 51652
- 51653
- 51654
- 56027 (2%)
- 57034 (4%)
These are the Census Bureau's ZIP code areas, which match residential ZIP codes closely. ZIP codes used only for PO boxes or a single organization aren't included. How ZIP codes are matched
2024 presidential vote
Shares of the votes for the two of them; other candidates are left out. Iowa used the same lines in 2024, so this is added up from precinct results. A precinct split between districts is divided by its House votes, so the figures are close estimates. Where the votes come from
U.S. House
Chris McGowan, Republican
Elected November 3, 2026, takes office January 3, 2027.
Unofficial results from the Iowa Secretary of State, checked November 6, 2026. A race shows a winner once news decision desks have called it. Results become official when the state certifies them. Where this comes from
Iowa's senators
- Joni Ernst, RepublicanSeat on the November 3, 2026 ballot: Josh Turek, Democrat, won and takes office January 3, 2027.
- Chuck Grassley, Republican
Senators are elected by the whole state, so district lines don't change who they are. Senators serving as of November 6, 2026. Senators elected in November 2026 take office January 3, 2027. Where this comes from
Where it sits in Iowa
- Very compact (0 to 19)
- Compact (20 to 39)
- Middle (40 to 59)
- Irregular (60 to 79)
- Very irregular (80 to 100)
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