Union Valley, TX Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Union Valley, a city in Rockwall County, Texas.
Overnight
73°F
Mostly Clear
Mostly clear. Low around 73, with temperatures rising to around 75 overnight. South wind around 5 mph.
7-day forecast for Union Valley
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 73°F | Mostly Clear | 5 mph S | 0% |
| Saturday | 99°F | Sunny | 5 to 10 mph SSW | 0% |
| Saturday Night | 74°F | Mostly Clear | 5 to 10 mph S | 0% |
| Sunday | 100°F | Mostly Sunny | 5 to 10 mph S | 6% |
| Sunday Night | 74°F | Mostly Cloudy then Chance Showers And Thunderstorms | 5 mph SSE | 37% |
| Monday | 98°F | Chance Showers And Thunderstorms | 5 mph WSW | 37% |
| Monday Night | 72°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 5 mph NNE | 20% |
| Tuesday | 95°F | Mostly Sunny | 5 to 10 mph NNE | 11% |
| Tuesday Night | 69°F | Partly Cloudy | 5 to 10 mph NE | 11% |
| Wednesday | 93°F | Mostly Sunny | 5 to 10 mph ENE | 9% |
| Wednesday Night | 69°F | Partly Cloudy | 5 mph ENE | 3% |
| Thursday | 93°F | Mostly Sunny | 5 mph E | 2% |
| Thursday Night | 69°F | Partly Cloudy | 5 mph E | 1% |
| Friday | 93°F | Mostly Sunny | 5 mph E | 3% |
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 Sep 19, 2026.