Union, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Union, a city in Franklin County, Missouri.
Today
89°F
Sunny
Sunny, with a high near 89. South wind around 5 mph.
7-day forecast for Union
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 89°F | Sunny | 5 mph S | 0% |
| Tonight | 67°F | Mostly Clear | 1 to 5 mph S | 0% |
| Wednesday | 91°F | Sunny | 2 mph S | 12% |
| Wednesday Night | 70°F | Slight Chance Showers And Thunderstorms | 2 mph S | 65% |
| Thursday | 88°F | Showers And Thunderstorms Likely | 2 mph S | 69% |
| Thursday Night | 68°F | Partly Cloudy then Chance Showers And Thunderstorms | 1 mph S | 32% |
| Friday | 88°F | Chance Showers And Thunderstorms | 1 mph SW | 32% |
| Friday Night | 69°F | Chance Showers And Thunderstorms | 0 mph | 27% |
| Saturday | 91°F | Chance Showers And Thunderstorms | 2 mph SW | 27% |
| Saturday Night | 71°F | Mostly Clear | 2 mph S | 7% |
| Sunday | 93°F | Sunny | 5 mph SW | 3% |
| Sunday Night | 73°F | Mostly Clear | 3 mph S | 5% |
| Monday | 95°F | Sunny | 5 mph SW | 4% |
| Monday Night | 74°F | Mostly Clear | 5 mph S | 10% |
Forecast source: National Weather Service (api.weather.gov) for Union (38.438, -90.996). Updated through the day.
Growing snapshot for Union
Last spring frost
Apr 11
First fall frost
Oct 23
Growing season
194 days
Hardiness zone
6b
More local growing data for Union: nearby ZIP 63084 weather · frost dates · planting calendar · Missouri frost dates
Nearby towns & communities
Berger
Charmwood
Gerald
Gray Summit
LaBarque Creek
Lake St. Clair
Lake Tekakwitha
Leslie
Miramiguoa Park
New Haven
Oak Grove Village
Pacific
Parkway
St. Clair
Stanton
Sullivan
Three Creeks
Villa Ridge
Washington
Climate data from the nearest NOAA station, Union, Mo (1.8 mi from Union). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.