51040 ZIP Code — Onawa, IA

Monona County, Iowa

ZIP code 51040 is located in Onawa, Iowa, within Monona County. It covers approximately 129.51 square miles and serves a population of 3,422 residents. This is a standard ZIP code in the Central (CT) timezone, served by area code 712.

About ZIP code 51040

The housing stock consists of predominantly single-family detached homes. Most homes were built in the pre-1940, giving the area an established character. Median home value is $112,600. Owner-occupancy is high at 78%, well above the national average.

Median household income is $55,559. 43% of households receive Social Security income, suggesting a notable retiree or disability population.

The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. The average commute of 20 minutes is near the national average.

College attainment at 11% is below the national average, consistent with a trades and production-oriented local economy.

Health indicators show elevated rates of smoking (20%) compared to national benchmarks.

Overall, ZIP code 51040 reflects a community defined by a trades-oriented workforce, high homeownership, and a significant Social Security-dependent population.

3,422

population

129.51

sq mi land

Standard

ZIP type

Central (CT)

timezone

51040 ZIP code map

Cities in ZIP code 51040

Below are the cities the US Postal Service accepts for ZIP code 51040. Using any city not on this list may result in mail delivery delays.

City	Status
Onawa	Acceptable
Onawa	Preferred

Nearby ZIP codes

51523 Blencoe (5.7 mi) 68020 Decatur (8 mi) 51063 Whiting (11 mi) 51010 Castana (11.3 mi) 51558 Moorhead (14.2 mi) 68061 Tekamah (14.6 mi) 68039 Macy (14.7 mi) 51051 Rodney (15.3 mi) 51572 Soldier (16.1 mi) 51055 Sloan (16.7 mi) 51564 Pisgah (17.2 mi) 51026 Hornick (18 mi)

Demographics updated 05/2026

Population
Total population	3,422
Population density	26 / sq mi
State FIPS	19
County FIPS	133

Geography
Land area	129.51 sq mi
Water area	1.61 sq mi
Latitude	41.9959
Longitude	-96.1025
Timezone	Central (CT)
Area code	712

Total population by age

Gender

Race & ethnicity

Economics updated 05/2026

Household income

Income range	This ZIP	County avg	State avg
Under $50k	50.4%	47.2%	40.1%
$50k – $100k	31.9%	33.9%	33.4%
$100k – $200k	14.3%	16.1%	21.5%
Over $200k	3.3%	2.8%	5.0%

Demographics & statistics

3,422

Population

People per sq mi

38.0

Median age

$55,559

Median household income

$30,035

Per capita income

$112,600

Median home value

$782

Median monthly rent

78.2%

Home ownership

16.7%

Poverty rate

2.9%

Unemployment

1,389

Housing units

10.7%

Bachelor's or higher

Age distribution

Male Female

Under 5

5–9

102

10–14

107

139

15–19

146

20–24

217

25–34

227

211

35–44

220

182

45–54

190

55–59

100

60–64

100

134

65–74

140

142

75–84

149

85+

← Male

Female →

Age summary

Group	Count	%
Under 18	759	22.2%
18 and over	2,663	77.8%
65 and over	727	21.2%
Median age	38.0 years

Race & ethnicity

White 95.5%

Two or more races 3%

Hispanic or Latino 0.6%

Native Hawaiian / Pacific Islander 0.6%

Black or African American 0.3%

Group	Count	%
White	3,290	95.5%
Two or more races	103	3%
Hispanic or Latino	22	0.6%
Native Hawaiian / Pacific Islander	20	0.6%
Black or African American	9	0.3%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	50.4%	47.2%	40.1%
$50k – $100k	31.9%	33.9%	33.4%
$100k – $200k	14.3%	16.1%	21.5%
Over $200k	3.3%	2.8%	5.0%

Under $10k 5.6%

$10k–$15k 4.5%

$15k–$25k 11.6%

$25k–$35k 6.9%

$35k–$50k 16.9%

$50k–$75k 19.6%

$75k–$100k 13.4%

$100k–$150k 15.6%

$150k–$200k 2.2%

$200k+ 3.7%

Range	% of households
Under $10k	5.6%
$10k–$15k	4.5%
$15k–$25k	11.6%
$25k–$35k	6.9%
$35k–$50k	16.9%
$50k–$75k	19.6%
$75k–$100k	13.4%
$100k–$150k	15.6%
$150k–$200k	2.2%
$200k+	3.7%
Median income	$55,559

Housing

Home values

Under $50k 20.4%

$50k–$100k 23.8%

$100k–$150k 17.6%

$150k–$200k 13.9%

$200k–$300k 15.7%

$300k–$500k 5.8%

$500k–$1M 2.6%

$1M+ 0.3%

Housing overview

Metric	Value
Median home value	$112,600
Median rent / month	$782
Owner occupied	78.2%
Renter occupied	21.8%
Vacant	13.3%
Single-family detached	86.7%
Large apartment buildings	7.4%
Mobile homes	2.7%
Median rooms	6.1
Avg household size (owned)	2.37

Year built

Era	%
2020 or later	0.2%
2010–2019	5.3%
2000–2009	4.3%
1990–1999	6.9%
1980–1989	5.0%
1970–1979	11.3%
1960–1969	13.1%
1950–1959	5.4%
1940–1949	9.9%
1939 or earlier	38.8%

Bedrooms

Size	% of units
No bedroom (studio)	3.1%
1 bedroom	8.6%
2 bedrooms	24.5%
3 bedrooms	45.2%
4 bedrooms	13.4%
5+ bedrooms	5.2%

Vehicles per household

Vehicles	% of households
No vehicle	2.8%
1 vehicle	35.9%
2 vehicles	34.6%
3 or more	26.7%

Heating fuel

Fuel type	%
Utility gas	60.7%
Electricity	27.5%
Propane / LP gas	7.1%
Fuel oil	0.7%
Wood	0.5%

Households & families

Household type	Count	%
Married-couple family	609	41.0%
Cohabiting couple	137	9.2%
Male householder, no spouse	330	22.2%
Female householder, no spouse	409	27.5%
Households with children under 18	360	24.2%
Households with seniors (65+)	540	36.4%
Average household size	2.25

Marital status

Status	Male	Female
Never married	34.4%	21.1%
Married	44.8%	48.0%
Separated	3.6%	3.5%
Widowed	6.2%	15.4%
Divorced	11.0%	12.0%

Education

Less than 9th grade 2.1%

Some HS, no diploma 6.5%

HS graduate 40.9%

Some college, no degree 30.7%

Associate's degree 9.1%

Bachelor's degree 8.8%

Graduate / professional 1.9%

Metric	%
HS diploma or higher	91.4%
Bachelor's or higher	10.7%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	33	4.7%
Kindergarten	21	3.0%
Elementary school	331	47.4%
High school	201	28.8%
College / grad school	113	16.2%

Employment

Industry of employment

Education & healthcare 25.4%

Arts, food & hospitality 11.4%

Transportation & utilities 9.0%

Retail trade 8.7%

Manufacturing 8.6%

Construction 8.1%

Agriculture & mining 7.2%

Other services 6.1%

Finance & real estate 5.9%

Professional & management 4.0%

Wholesale trade 2.8%

Public administration 2.2%

Information 0.6%

Occupation

Category	%
Management, business & arts	29.7%
Service	20.8%
Sales & office	23.1%
Natural resources & construction	13.7%
Production & transportation	12.7%

Employment type

Type	%
Private sector	78.6%
Government	11.0%
Self-employed	10.4%
Unpaid family workers	0.0%

Commute

Method	%
Drive alone	81.2%
Carpool	7.4%
Public transit	0.9%
Walk	1.4%
Work from home	8.8%
Other means	0.4%
Avg commute (minutes)	20.3

Poverty

All people 16.7%

Under 18 years 16.8%

18 and over 16.7%

Married-couple families 6.9%

Female-led households 27.3%

Income support

Source	% of households
Social Security	42.6%
Retirement income	21.5%
Supplemental Security	6.2%
Cash public assistance	2.4%
Food stamps / SNAP	11.6%

Health indicators

Condition	%
Obesity	36.9%
High blood pressure	40.5%
High cholesterol	37.3%
Diabetes	13.3%
Heart disease	9.3%
Stroke	4.4%
Asthma	9.7%
Arthritis	30.8%
Kidney disease	4.0%
Pulmonary disease	9.7%
Cancer	8.7%

Behavior / access	%
Smoking	20.2%
Binge drinking	19.1%
No physical activity	29.3%
Less than 7 hrs sleep	31.1%
Depression	17.9%
Fair or poor health	17.2%
Poor mental health	13.8%
Poor physical health	12.4%
No health insurance	10.3%
Visited doctor (checkup)	76.9%
Visited dentist	60.0%
Cholesterol screening	88.8%
Teeth loss	17.7%

Veterans & disability

Veterans	Count	%
Civilian veterans	213	8.0%

Disability	%
Any disability	18.9%
Under 18	5.4%
18–64 years	18.9%
65 and over	34.0%

Health insurance coverage

Type	%
Private insurance	59.2%
Public insurance	55.0%
No insurance	5.8%
Uninsured under 19	0.9%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	3,237	94.6%
Spanish	0	0.0%
Other Indo-European	0	0.0%
Asian & Pacific Islander	0	0.0%
Other languages	0	0.0%

Place of birth & citizenship

Origin	Count	%
Native born (US)	3,422	100.0%
Born in same state	3,399	99.3%
Born in different state	2,658	77.7%
Foreign born	23	0.7%
Naturalized citizen	0	0.0%
Not a US citizen	0	0.0%

Ancestry

Ancestry	Count	%
Italian	693	20.3%
Arab	292	8.5%
Dutch	217	6.3%
French	192	5.6%

Ancestry	Count	%
German	67	2%
Polish	67	2%
English	52	1.5%
Irish	15	0.4%

Technology access

Metric	% of households
Computer access	43.4%
Internet access	88.6%

Source: U.S. Census Bureau, American Community Survey 2025 estimates.

Frequently asked questions about ZIP code 51040

What city is ZIP code 51040 in?

ZIP code 51040 is primarily assigned to Onawa, Iowa.

What county is ZIP code 51040 in?

ZIP code 51040 falls within Monona County, Iowa.

How educated is the population of ZIP code 51040?

11% of residents hold a bachelor's degree or higher — below the national average of ~33%, consistent with a trades-oriented local economy.

Does ZIP code 51040 have a large retiree population?

43% of households in ZIP code 51040 receive Social Security income, suggesting a significant retiree or disability population.

What is the poverty rate in ZIP code 51040?

17% of residents in ZIP code 51040 live below the poverty line, above the national average.

What is the typical home value in ZIP code 51040?

The median home value in ZIP code 51040 is $112,600.

What timezone is ZIP code 51040 in?

ZIP code 51040 observes the CST timezone.