Arnold, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Arnold, a city in Jefferson County, Missouri.
Today
90°F
Patchy Fog then Sunny
Patchy fog before 8am. Sunny, with a high near 90. Southeast wind around 3 mph.
7-day forecast for Arnold
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 90°F | Patchy Fog then Sunny | 3 mph SE | 0% |
| Tonight | 68°F | Mostly Clear | 3 mph SE | 0% |
| Wednesday | 91°F | Sunny | 5 mph S | 7% |
| Wednesday Night | 71°F | Slight Chance Showers And Thunderstorms | 6 mph S | 60% |
| Thursday | 88°F | Showers And Thunderstorms Likely | 3 mph S | 67% |
| Thursday Night | 70°F | Chance Showers And Thunderstorms | 2 mph S | 42% |
| Friday | 89°F | Chance Showers And Thunderstorms | 3 mph SW | 42% |
| Friday Night | 70°F | Chance Showers And Thunderstorms | 2 mph S | 34% |
| Saturday | 91°F | Chance Showers And Thunderstorms | 3 mph SW | 34% |
| Saturday Night | 72°F | Mostly Clear | 5 mph S | 7% |
| Sunday | 93°F | Sunny | 6 mph SW | 7% |
| Sunday Night | 74°F | Mostly Clear | 6 mph S | 6% |
| Monday | 95°F | Sunny | 6 mph SW | 6% |
| Monday Night | 75°F | Slight Chance Showers And Thunderstorms | 7 mph SW | 15% |
Forecast source: National Weather Service (api.weather.gov) for Arnold (38.426, -90.369). Updated through the day.
Growing snapshot for Arnold
Last spring frost
Apr 9
First fall frost
Oct 26
Growing season
197 days
Hardiness zone
7a
More local growing data for Arnold: nearby ZIP 63010 weather · frost dates · planting calendar · Missouri frost dates
Nearby towns & communities
Barnhart
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Byrnes Mill
Cedar Hill
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Crystal City
De Soto
Fenton
Festus
Herculaneum
High Ridge
Hillsboro
Horine
Imperial
Kimmswick
Murphy
Olympian Village
Parkdale
Peaceful Village
Pevely
Raintree Plantation
Scotsdale
Summer Set
Climate data from the nearest NOAA station, Festus, Mo (13.7 mi from Arnold). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.