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Single Family ResidenceResidential
$70,295$76 / ft²
TopHap EstimateOur estimate of what this home would sell for today, based on nearby sales, the home's size and features, and local price trends. It is a starting point, not an appraisal.· confidence 70How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Aug 30, 2026
Last sold for $65,000 on Aug 1, 2025

331 20TH ST SE

MASON CITY, IA 50401
2
Beds
1
Baths
930 ft²
Living AreaTotal finished area of the structures, from county records. Some counties include shared space like hallways or a building gym, so it may not match a listing.
0.17 ac
Lot SizeThe size of the land the home sits on, from county records.
1920
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.
4
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.
1
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$70K
$49K low$91K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$65,000 · Aug 1, 2025

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$956 (2025)
Assessed ValueThe value the county assigns to this home to calculate property tax. It is often lower than what the home would sell for.$66,860 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$13,790
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$53,070
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$59,660
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$66,860

Climate Risk

Overall riskThe average of the five hazard scores below, on a 0 to 100 scale. Higher means greater projected risk over the coming decades.31
25
FloodProjected flooding risk from rivers, heavy rain, and storm surge, scored 0 to 100. Higher is riskier.
6
WildfireProjected wildfire risk, scored 0 to 100, based on how much land burns in a typical year. Higher is riskier.
61
HeatProjected heat risk, scored 0 to 100, based on how many extremely hot days a year are expected. Higher is riskier.
51
StormProjected risk from heavy rainstorms, scored 0 to 100, based on how often extreme rainfall is expected. Higher is riskier.
12
DroughtProjected water shortage risk, scored 0 to 100. Higher means more strain on the local water supply.
Projected Flood DepthHow deep a serious flood is expected to get here at some point in the next 30 years. Shown in inches.8 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.6%
FEMA Flood ZoneFEMA's flood zone for this address. Zones starting with A or V are high risk, and lenders usually require flood insurance there.0.2 percent flood zone

Scores 0–100; higher = greater projected risk.

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
StyleThe architectural style of the home, such as ranch or colonial.Conventional
CountyCERRO GORDO
Lot (acres)The size of the land the home sits on, from county records.0.17
ConstructionThe main material the home's frame and walls are built from.Steel Frame
RoofThe main material covering the roof, such as asphalt shingle or tile.Asphalt
HeatingThe type of heating system in the home.Forced Air With Air Conditioning
CoolingThe type of cooling or air conditioning in the home.Yes
GarageWhether the property has a garage, and details like whether it is attached to the home.Garage, Detached
PoolWhether the property has a pool, and what kind, such as in-ground.No
FeaturesExtra features found in county records. Records are not complete everywhere, so a missing feature does not always mean the home lacks it.Patio · 165 ft²Porch · 241 ft²

Transaction History(2)

Sales and refinances filed with the county for this home. Not every transfer is a normal sale, so check the type before comparing prices.

Assigned SchoolsThe public schools this address is zoned for. Boundaries change, so confirm with the district before you count on it.

E
Roosevelt Elementary SchoolC
Elementary · Grades PK–4 · 0.3 mi
M
John Adams Middle SchoolB-
Middle · Grades 7–8 · 1.8 mi
H
Mason City High SchoolC
High · Grades 9–12 · 1.8 mi

District: Mason City Community School District

Neighborhood · ZIP 50401These are comparison scores, not percentages. 100 equals the national average, so 150 means about 50% above average.

CrimeLocal crime compared with the rest of the country, where 100 is average. It reflects things like population density, income, and how crime gets reported.95
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.84
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.15

Index scale: 100 = US average (tick). Lower is better.

Homes occupiedThe share of homes here that someone lives in. The rest sit empty, including vacation and for-sale homes.89%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.14%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.8.5%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.0.9%
PopulationHow many people live in this area.29,055
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.202 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$65,986
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$80,217
Average tempThe average temperature here across a full year.46°F
Annual precipHow much rain and melted snow falls here in a typical year.34 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.61%

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Data by ATTOM. Valuations are automated estimates, not appraisals. Photos from Google Street View and may not depict the current property state.

How this home compares

331 20th St Se measured against every home in its neighborhood, its ZIP code and its county, using county assessor records refreshed nightly. A home can stand out in one of those areas and look ordinary in another, because each one holds a different mix of homes.

  • Worth less than 93% of homes in Cerro Gordo County
  • Costs less per square foot than 91% of homes in Cerro Gordo County
  • Smaller than 81% of homes in Cerro Gordo County
  • Older than 77% of homes in Mason City 50401

What homes are worth in Mason City 50401

Each bar is how many homes fall in that price range. The marker is this home.

This home
$42K$574K

This home is worth more than 10% of homes in Mason City 50401.

How it measures up in Mason City 50401

The dot is this home. The mark in the middle is the typical home in Mason City 50401.

Estimated value$70,295
CheaperTypical $154,956Pricier

Pricier than 10% of homes nearby

Price per ft²$76
CheaperTypical $135Pricier

Pricier than 12% of homes nearby

Living area930 ft²
SmallerTypical 1,216 ft²Bigger

Bigger than 22% of homes nearby

Lot size0.17 ac
SmallerTypical 0.17 acBigger

Bigger than 47% of homes nearby

Year built1920
OlderTypical 1950Newer

Newer than 23% of homes nearby

How 331 20th St Se ranks against every home in each area.
MeasureThis homeMason City 50401Cerro Gordo County
Estimated valuepricier than$70,29510% of homes7% of homes
Price per ft²pricier than$7612% of homes9% of homes
Living areabigger than930 ft²22% of homes19% of homes
Lot sizebigger than0.17 ac47% of homes40% of homes
Year builtnewer than192023% of homes23% of homes

About 331 20th St Se

How much is 331 20th St Se, Mason City, IA worth?

The TopHap Estimate for 331 20th St Se, Mason City, IA is $70,295 as of Aug 30, 2026. The likely range is $49,451 to $91,139. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 331 20th St Se, Mason City, IA last sell?

331 20th St Se, Mason City, IA last sold on Aug 1, 2025 for $65,000, according to the county's recorded deed.

How big is 331 20th St Se, Mason City, IA?

331 20th St Se, Mason City, IA has 2 bedrooms, 1 bathrooms, 930 square feet of living space and a 0.17-acre lot.

When was 331 20th St Se, Mason City, IA built?

331 20th St Se, Mason City, IA was built in 1920, making it 106 years old. It is a conventional home. The building has 1 story.

What schools serve 331 20th St Se, Mason City, IA?

331 20th St Se, Mason City, IA is assigned to Roosevelt Elementary School (elementary), rated C; John Adams Middle School (middle), rated B-; Mason City High School (high), rated C. All sit in Mason City Community School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 331 20th St Se, Mason City, IA compare to other homes in Mason City 50401?

Among the 11,561 homes in Mason City 50401, it is worth more than 10% of them ($70,295 against a typical $154,956), its price per square foot is higher than 12% of them ($76 against a typical $135), it is bigger than 22% of them (930 ft² against a typical 1,216 ft²), its lot is bigger than 47% of them (0.17 ac against a typical 0.17 ac) and it is newer than 23% of them (1920 against a typical 1950). Measured against all of Cerro Gordo County, it is worth more than 7% of homes there. These shares are recounted nightly from the full county assessor record for each area, not from active listings.

What are the property taxes on 331 20th St Se, Mason City, IA?

The 2025 property tax bill for 331 20th St Se, Mason City, IA was $956. The county assessed it at $66,860.

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