Arnold is a city in northeastern Jefferson County, Missouri, situated near the confluence of the Meramec and Mississippi rivers. A suburb of St. Louis, the city lies within the Greater St. Louis metropolitan statistical area. The population was 20,858 at the 2020 United States census, which makes it the most populous community in the county.

Official town website ↗

From Wikipedia, licensed CC BY-SA 4.0 · facts via Wikidata (CC0)

How Arnold ranks

All →

#11Most conserved land in MO #51Lowest depression in MO #20Rent easiest to afford in MO All MO rankings →

Town numbers

ZIP code63010

Area code636

Living in Arnold

Housing in Arnold

$276K▲ 3.7% in a year Typical home value · Zillow

The typical Arnold home is worth about $276,000, up 3.7% in a year, close to the Missouri typical home.

A strong seller's market

Buyer’sBalancedSeller’s

Days on market15

Sale-to-list102.8%

Sold in May18

Zillow Home Value Index · Redfin Data CenterHousing market →

Safety in Arnold

—

Not graded

A grade needs all of the FBI's latest years (2023–2025). Arnold's police department reported only 2023 and 2025, so we don't grade it yet. The figures below are still real.

Violent crime per 1,000

Arnold 0.7

Missouri 4.3

U.S. 3.3

Property crime per 1,000

Arnold 8

Missouri 16.9

U.S. 15.5

FBI crime data, 2025 · crimes reported to policeCrime & safety →

Work & commute in Arnold

Full picture →

Most working residents leave Arnold for work: only 7% work in town. The top destinations are St. Louis (16%), Fenton (4%) and Maryland Heights (4%). Half commute less than 15 miles.

St. Louis

16%

Fenton

Maryland Heights

Creve Coeur

7%Work in townlive and work in Arnold 15 miWhere do people commute?the commute map 10,015Jobs based herebalanced

Census LEHD 2023 · ACSWork & commute in Arnold →

Health in Arnold

B⁻

Health Grade B−

Healthier than 46% of U.S. towns on seven CDC estimates.

Compared with Missouri

5better than MO

of 32 measures CDC estimates. The other 27 are too close to call.

Conditions 1▲ 11 close Habits all close Care all close Mind all close Everyday needs 4▲ 0 close

BetterToo close to callWorse

What stands out

11.1%Fewer older adults who have lost all their teethMO 15.8% · better 10.8%Fewer adults facing food insecurityMO 13.7% · better

Care nearby

Mercy Hospital SouthSaint Louis · 5.9 mi · ER

Compass HealthArnold · 0.5 mi · sliding-scale fees

Primary careShortage · county-wide

DentalNo shortage

Mental healthNo shortage

CDC PLACES 2025 · modeled estimates for adults · CDC's estimate for Arnold · CMS · HRSAHealth in Arnold →

Natural hazards in Arnold

High

Expected storm and flood damage is higher than in 70% of U.S. communities.

🌊 Inland flooding🏚️ Earthquakes🌪️ Tornadoes

982Does Arnold flood?paid flood claims since 1978 9Disasters that paid out herefederal disasters sent FEMA money to Arnold

FEMA National Risk Index December 2025 · OpenFEMANatural hazards in Arnold →

Climate in Arnold

Full climate →

Arnold has chilly winters and warm summers. A typical July afternoon reaches 89°, a January night drops to 23°, and about 10 inches of snow falls in a normal winter.

44° / 26°Winter

67° / 46°Spring

87° / 67°Summer

69° / 47°Fall

How much snow does Arnold get?About 10 inches a winter.Rain & snow →When is the first frost?Around Oct 26, with the last in spring around Apr 9.Frost dates →Is it warmer than it used to be?+1.1° vs. the 20th century.Then & now →

NOAA U.S. Climate Normals, 1991–2020Climate in Arnold →

Schools in Arnold

All Arnold schools →

School Grade B

The public schools Arnold’s kids attend, from kindergarten through graduation, outperform 61% of Missouri’s districts on state tests and graduation. Among towns with similar incomes, they sit near the middle.

See how Arnold’s schools compare in MO →

DistrictFOX C-6Schools8

Rockport Heights Elem. BElementary · Grades K–5 · 386 students Fox Elem. C+Elementary · Grades K–5 · 355 students Sherwood Elem. B+Elementary · Grades K–5 · 347 students St. Johns Lutheran SchoolElementary · Grades PK–8 · 255 students Holy Child Catholic SchoolElementary · Grades PK–8 · 238 students Fox Middle C+Middle · Grades 6–8 · 570 students

School data from the U.S. Department of Education (NCES, EDFacts). The School Grade is our own summary of state test results and graduation rates, graded within MO. Ratings are from neighbors.