51040 Property Tax Rate
Onawa, Iowa · Part of Monona County
Effective Tax Rate
1.28%
13.2% below state avgMedian Annual Tax
$1,793
$149/mo escrow
Estimate Your Tax
Annual Tax
$1,793
Monthly
$149
Eff. Rate
1.28%
Buyer decision brief
What ZIP 51040 means for your housing budget
Use this ZIP page to compare recurring tax burden before you compare listing prices. The numbers below are Census ZCTA estimates, so they are strongest for neighborhood comparison and weakest for parcel-specific tax planning.
Monthly escrow signal
$149/mo
Based on median annual tax paid
State context
Near the Iowa average
Iowa average: 1.28%
Data confidence
High confidenceThe Census margin of error is $182, about 10% of the median tax estimate.
Verify before you offer
- Confirm parcel assessed value with Monona County assessor.
- Check homestead, senior, veteran, and disability exemptions.
- Ask whether purchase triggers reassessment or value-cap reset.
- Review school district and special assessment boundaries.
Lower-rate similar ZIPs
This is informational content, not tax, legal, or mortgage advice. Local assessor records remain the source of truth for a specific property.
Data confidence ledger
Can you trust ZIP 51040 for comparison?
ACS vintage
2019-2023 ACS 5-Year Estimates
Five-year Census ZCTA estimates.
ZCTA caveat
Census area, not parcel boundary
USPS ZIP routes and taxing districts can differ inside the same area.
Field completeness
3/3 required fields
Median tax, home value, and derived rate are present.
MOE status
Strong ACS confidence
$182 tax MOE, 10% of the median tax estimate.
Last site refresh
March 10, 2026
Dataset and page-quality audit run locally before publication.
County fallback
County context only
Monona County is used for assessor verification and broader context.
Tax bill anatomy
What can change your actual bill in ZIP 51040
Use the ZIP estimate to compare neighborhoods, then verify these parcel-level inputs before relying on a payment estimate.
Assessed value
The ZCTA median home value is $140,400, but your bill starts with the local assessed value for a specific parcel.
Effective rate
The displayed rate is 1.28%, derived from median tax paid divided by median home value.
Exemptions
Homestead, senior, veteran, disability, and local exemptions can reduce taxable value. Confirm eligibility before estimating escrow.
Reassessment
A purchase can change assessed value depending on Iowa and county rules. Ask how sale price affects the next assessment cycle.
Escrow impact
The median tax paid in this ZCTA equals about $149 per month before insurance, HOA dues, or special assessments.
Assessor verification
Monona County assessor or tax collector records are the source of truth for parcel taxes, appeal windows, and exemptions.
How ZIP 51040 Compares
Median Annual Property Tax
ZIP 51040
1.28%
Effective rate
Iowa Avg
1.28%
Effective rate
National Avg
1.10%
Effective rate
State Ranking
Property Tax Rank in Iowa
Higher than 52% of ZIP codes in Iowa(52th percentile, 908 ZIPs compared)
Property Tax Analysis
Property Tax Insights for ZIP 51040
Property owners in ZIP code 51040 (Onawa, Iowa) pay a median of $1,793/year in property taxes on homes valued at $140,400. This translates to an effective tax rate of 1.28%, which is near the Iowa state average of 1.28%.
The monthly property tax burden for a median-valued home in 51040 is approximately $149, which factors into escrow payments on mortgages. This ZIP code is located within Monona County. This is $272 less than the Iowa average of $2,065/year.
Compared to similar ZIP codes in Iowa, 51040 has higher property taxes. ZIP codes with similar effective rates include 52338 (1.28%) and 50157 (1.28%).
In Onawa, property taxes represent approximately 3.0% of the median household income of $60,642, providing context for the relative tax burden on homeowners in this area.
If you're considering purchasing a home in 51040, keep in mind that property taxes are based on the assessed value assigned by the local assessor, which may differ from the purchase price. In some states, properties are reassessed at or near the sale price upon transfer of ownership. For the most current tax information for a specific property, consult Monona County's tax assessor directly.
Frequently Asked Questions
What is the property tax rate in ZIP code 51040?
How much are property taxes in Onawa, IA (51040)?
How does ZIP 51040 compare to the Iowa average?
What is the median home value in ZIP 51040?
What county is ZIP code 51040 in?
Margin of Error
The median property tax estimate for this ZIP code has a margin of error of ±$182. ZCTA-level data has wider margins than county-level estimates due to smaller sample sizes.
County-Level Data
ZIP code 51040 is part of Monona County, Iowa. View the full county profile for broader context and more data.
View Monona County on TaxByCounty →Why compare these ZIPs?
Better comparison set for ZIP 51040
Each ZIP highlights a homebuyer tradeoff: lower rate, stronger value context, shared county rules, city boundary changes, or nearby missing data.
51051
Rodney, IA
0.96 percentage points lower than ZIP 51040.
Rate
0.32%
Tax
$513
Quality
71
51572
Soldier, IA
0.37 percentage points lower than ZIP 51040.
Rate
0.90%
Tax
$1,130
Quality
71
51060
Ute, IA
0.25 percentage points lower than ZIP 51040.
Rate
1.03%
Tax
$1,074
Quality
77
51523
Blencoe, IA
0.21 percentage points lower than ZIP 51040.
Rate
1.06%
Tax
$1,250
Quality
82
51063
Whiting, IA
0.17 percentage points lower than ZIP 51040.
Rate
1.10%
Tax
$1,284
Quality
82
51010
Castana, IA
0.17 percentage points lower than ZIP 51040.
Rate
1.10%
Tax
$1,192
Quality
82
51034
Mapleton, IA
0.13 percentage points lower than ZIP 51040.
Rate
1.14%
Tax
$1,362
Quality
77
50061
Cumming, IA
$376,200 higher median home value than ZIP 51040.
Rate
1.39%
Tax
$7,155
Quality
80
Data from U.S. Census Bureau, American Community Survey 2019-2023 5-Year Estimates (ZCTA level). ZIP Code Tabulation Areas (ZCTAs) are Census approximations of USPS ZIP codes.
Estimates are informational only and should not be used as financial or legal advice.