Johnston, IA GIS Map
Johnston is a city in Polk County, Iowa, with a population of about 22,582. The map below shows its location, boundary and surrounding roads, with federal GIS layers you can turn on for the area.
- County
- Polk County
- Population
- 22,582
- Elevation
- 831 ft
- Coordinates
- 41.6731, -93.6975
- ZIP code
- 50131
- Land area
- 19.5 sq mi
- Time zone
- America/Chicago
About Johnston, IA
Johnston is a city in Polk County, Iowa, United States. The population was 24,064 in the 2020 census, a large increase from the 8,649 population in 2000. It is part of the Des Moines–West Des Moines Metropolitan Statistical Area.
Source: Wikipedia (CC BY-SA 4.0)
Cities Near Johnston
- Urbandale, IA3 mi
- Clive, IA5 mi
- Ankeny, IA6 mi
- Des Moines, IA7 mi
- West Des Moines, IA8 mi
- Waukee, IA10 mi
- Norwalk, IA14 mi
- Indianola, IA23 mi
Other Cities in Polk County
GIS Data for Johnston, IA
The Johnston map loads live federal GIS layers in your browser, so you can check flood zones, terrain, land cover and district boundaries for any address in Johnston without a separate GIS login. Everything below is drawn from public U.S. government data.
Layers you can turn on
FEMA flood zones
National Flood Hazard Layer — flood insurance rate map zones.
Elevation contours and hillshade
USGS 3DEP terrain, so you can read slope and relief.
Land cover
NLCD land cover classes — forest, developed, wetland, water.
School districts
Census TIGER unified and elementary school district boundaries.
ZIP code and county boundaries
Census TIGER ZCTA and county boundary lines.
Map tools
Measure distance and area
Draw a line or polygon to get length in miles or area in acres.
Sketch and annotate
Add points, lines and shapes on top of the map.
Inspect any point
Click the map to read coordinates, elevation and the layers under your cursor.
Download the map
Save the current view as a PNG image.
Johnston Demographics
Source: U.S. Census Bureau, American Community Survey 2020-2024 5-year estimates.
Population
24,384
Households
9,259
Median household income
$106,551
Median age
37.4 years
Median home value
$369,100
Median gross rent
$1,338/mo
Owner-occupied homes
70.8%
Bachelor's degree or higher
57.8%
Below poverty level
10.2%
Land area
19.5 sq mi
Population density
1,251 / sq mi
County
ZIP codes in Johnston
Johnston Population Growth
Source: U.S. Census Bureau, 2010 Census and Population Estimates Program (Vintage 2024: April 2020 estimates base and July 1, 2024 estimate).
2010 Census
17,278
April 2020 (estimates base)
23,937
July 2024 estimate
25,022
Change 2010-2020
+38.5%
Change 2020-2024
+4.5%
Photos of Johnston
Hover over a photo to see it larger. Tap on mobile.
Photos from Wikimedia Commons, taken in or near Johnston. Credits and licenses are shown in the larger view.
Soils of Johnston
General soil map unit at the city center: Wadena-Coland-Clarion
Soil Properties
- Drainage class
- Poorly drained
- Hydrologic soil group
- B (moderate infiltration)
- Available water storage (0–150 cm)
- 24.6 cm
- Typical slope
- 1%
Soil Components
- Coland14%
Mollisols · Cumulic Endoaquolls
- Clarion10%
Mollisols · Typic Hapludolls
- Wadena9%
Mollisols · Typic Hapludolls
- Biscay7%
Mollisols · Typic Endoaquolls
- Cylinder7%
Mollisols · Aquic Hapludolls
- Canisteo6%
Mollisols · Typic Endoaquolls
Source: USDA NRCS U.S. General Soil Map (STATSGO2). General soil map data (1:250,000 scale) is not suitable for site-specific decisions.
Climate of Johnston
30-year averages (1991–2020) from the Des Moines Wsfo-Johnston, Ia weather station, elevation 959 ft, 4.6 miles from the city center.
Warmest month
Jul · avg high 85°F
Coldest month
Jan · avg low 13°F
Annual precipitation
36.2 in
Annual snowfall
38.0 in
Average Monthly Temperatures (°F)
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 30 | 35 | 49 | 62 | 72 | 81 | 85 | 83 | 76 | 63 | 48 | 35 |
| Avg low °F | 13 | 17 | 29 | 40 | 52 | 62 | 66 | 64 | 55 | 42 | 30 | 19 |
| Precip. in | 1.01 | 1.25 | 2.15 | 4.00 | 4.84 | 5.35 | 4.27 | 3.97 | 3.40 | 2.51 | 1.95 | 1.46 |
| Snow in | 9.7 | 10.5 | 5.0 | 1.6 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.5 | 2.2 | 8.3 |
Source: NOAA NCEI U.S. Climate Normals, 1991–2020. Conditions at the station may differ from other parts of the city.
Natural Hazard Risk in Johnston
FEMA National Risk Index ratings for Polk County, compared with all U.S. counties.
Overall risk
Score 92 of 100
Expected annual loss
Buildings, population & agriculture
Social vulnerability
Susceptibility to hazard impacts
Community resilience
Ability to prepare & recover
Risk by Hazard
- Strong WindVery High
- TornadoRelatively High
- HailRelatively High
- Heat WaveRelatively High
- DroughtRelatively High
- Inland FloodingRelatively Moderate
- Ice StormRelatively High
- Cold WaveRelatively High
- Winter WeatherRelatively High
- LightningRelatively Moderate
- LandslideRelatively Low
- EarthquakeRelatively Low
- WildfireVery Low
- HurricaneVery Low
Source: FEMA National Risk Index (December 2025 release). County-level ratings are relative to other U.S. counties and are not a property-specific assessment.
Johnston FAQ
What county is Johnston in?
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Johnston, Iowa is located in Polk County.
What is the population of Johnston?
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Johnston has a population of about 22,582, making it the number 24 of the 44 Iowa cities listed on GIS Map.
What is the elevation of Johnston?
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The elevation of Johnston is approximately 831 feet (253 meters) above sea level at the city center.
What ZIP codes are in Johnston?
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The ZIP code for Johnston is 50131.
What time zone is Johnston in?
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Johnston is in the Central Time zone (America/Chicago).
How far is Johnston from Des Moines?
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Johnston is about 7 miles from Des Moines, the capital of Iowa, in a straight line.
What cities are near Johnston?
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Cities near Johnston include Urbandale, IA (3 miles); Clive, IA (5 miles); Ankeny, IA (6 miles); Des Moines, IA (7 miles); West Des Moines, IA (8 miles).
Local notes for Johnston, IA
Questions and local knowledge from people who know the area. Every note is read before it appears here.