Union Valley, TX Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Union Valley, a city in Rockwall County, Texas.
Tonight
49°F
Mostly Clear
Mostly clear. Low around 49, with temperatures rising to around 51 overnight. Northwest wind 5 to 10 mph.
7-day forecast for Union Valley
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 49°F | Mostly Clear | 5 to 10 mph NW | 0% |
| Wednesday | 72°F | Mostly Sunny | 0 to 5 mph NW | 0% |
| Wednesday Night | 46°F | Patchy Fog | 0 mph | 0% |
| Thursday | 77°F | Patchy Fog then Mostly Sunny | 0 to 10 mph S | 10% |
| Thursday Night | 49°F | Partly Cloudy | 5 to 10 mph NW | 13% |
| Friday | 71°F | Sunny | 5 to 10 mph N | 0% |
| Friday Night | 43°F | Partly Cloudy | 5 mph N | 0% |
| Saturday | 68°F | Partly Sunny | 5 mph N | 1% |
| Saturday Night | 43°F | Partly Cloudy | 0 to 5 mph N | 6% |
| Sunday | 69°F | Sunny | 0 to 5 mph NNW | 2% |
| Sunday Night | 42°F | Clear | 0 to 5 mph N | 1% |
| Monday | 72°F | Sunny | 0 to 5 mph S | 1% |
| Monday Night | 43°F | Mostly Clear | 0 to 5 mph S | 0% |
| Tuesday | 75°F | Sunny | 0 to 5 mph S | 1% |
Forecast source: National Weather Service (api.weather.gov) for Union Valley (32.929, -96.249). Updated through the day.
Growing snapshot for Union Valley
Last spring frost
Mar 10
First fall frost
Nov 19
Growing season
254 days
Hardiness zone
8b
More local growing data for Union Valley: nearby ZIP 75189 weather · frost dates · planting calendar · Texas frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Lavon Dam, Tx (12 mi from Union Valley). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.