Newcastle, UT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Newcastle, a community in Iron County, Utah.
This Afternoon
80°F
Sunny
Sunny, with a high near 80. South southwest wind around 14 mph.
7-day forecast for Newcastle
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 80°F | Sunny | 14 mph SSW | 4% |
| Tonight | 46°F | Mostly Clear | 3 to 12 mph S | 4% |
| Saturday | 81°F | Sunny | 6 mph N | 0% |
| Saturday Night | 46°F | Mostly Clear | 6 mph E | 0% |
| Sunday | 81°F | Sunny | 3 to 7 mph NNE | 0% |
| Sunday Night | 48°F | Partly Cloudy | 2 mph S | 0% |
| Monday | 82°F | Mostly Sunny | 1 to 6 mph NE | 3% |
| Monday Night | 47°F | Chance Showers And Thunderstorms | 1 to 6 mph S | 44% |
| Tuesday | 77°F | Chance Rain Showers then Chance Showers And Thunderstorms | 0 to 5 mph E | 44% |
| Tuesday Night | 45°F | Slight Chance Showers And Thunderstorms then Mostly Clear | 0 to 3 mph NE | 12% |
| Wednesday | 81°F | Sunny | 0 to 5 mph NNE | 8% |
| Wednesday Night | 47°F | Mostly Clear | 0 to 3 mph E | 3% |
| Thursday | 82°F | Mostly Sunny | 0 to 5 mph NW | 6% |
| Thursday Night | 49°F | Partly Cloudy | 1 to 5 mph SSE | 11% |
Forecast source: National Weather Service (api.weather.gov) for Newcastle (37.663, -113.564). Updated through the day.
Growing snapshot for Newcastle
Last spring frost
May 31
First fall frost
Sep 20
Growing season
110 days
Hardiness zone
5b
More local growing data for Newcastle: nearby ZIP 84756 weather · frost dates · planting calendar · Utah frost dates
Nearby towns & communities
Beryl Junction
Brian Head
Cedar City
Cedar Highlands
Enoch
Kanarraville
Modena
Paragonah
Parowan
Summit
Climate data from the nearest NOAA station, Enterprise Beryl Jct, Ut (6.2 mi from Newcastle). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 18, 2026.