Arnold, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Arnold, a city in Jefferson County, Missouri.
Overnight
74°F
Clear
Clear, with a low around 74. South wind around 2 mph.
7-day forecast for Arnold
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 74°F | Clear | 2 mph S | 2% |
| Saturday | 99°F | Mostly Sunny | 2 to 6 mph SW | 4% |
| Saturday Night | 73°F | Partly Cloudy | 5 mph SW | 4% |
| Sunday | 94°F | Chance Rain Showers then Slight Chance Showers And Thunderstorms | 5 mph W | 28% |
| Sunday Night | 67°F | Showers And Thunderstorms Likely | 3 to 7 mph N | 65% |
| Monday | 80°F | Showers And Thunderstorms Likely | 7 mph N | 65% |
| Monday Night | 59°F | Showers And Thunderstorms Likely | 5 to 8 mph N | 61% |
| Tuesday | 72°F | Slight Chance Rain Showers then Partly Sunny | 9 mph N | 22% |
| Tuesday Night | 54°F | Mostly Cloudy | 3 to 9 mph N | 4% |
| Wednesday | 74°F | Mostly Sunny | 7 mph N | 1% |
| Wednesday Night | 55°F | Partly Cloudy | 2 to 6 mph N | 0% |
| Thursday | 77°F | Mostly Sunny | 2 to 6 mph N | 1% |
| Thursday Night | 57°F | Mostly Cloudy | 5 mph NE | 4% |
| Friday | 77°F | Partly Sunny | 2 to 6 mph NE | 7% |
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
Briarwood Estates
Byrnes Mill
Cedar Hill
Cedar Hill Lakes
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 Sep 19, 2026.