Newcastle, UT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Newcastle, a community in Iron County, Utah.
Today
97°F
Patchy Smoke then Sunny
Patchy smoke before noon. Sunny, with a high near 97. West southwest wind 5 to 12 mph.
7-day forecast for Newcastle
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 97°F | Patchy Smoke then Sunny | 5 to 12 mph WSW | 0% |
| Tonight | 63°F | Mostly Clear | 2 to 12 mph S | 0% |
| Wednesday | 96°F | Sunny | 2 to 9 mph SW | 0% |
| Wednesday Night | 64°F | Clear | 5 to 10 mph SSW | 0% |
| Thursday | 97°F | Sunny | 2 to 7 mph SSW | 3% |
| Thursday Night | 65°F | Mostly Clear | 3 to 8 mph SSW | 2% |
| Friday | 97°F | Sunny | 1 to 5 mph SW | 4% |
| Friday Night | 65°F | Partly Cloudy | 6 mph SW | 1% |
| Saturday | 97°F | Sunny then Slight Chance Showers And Thunderstorms | 2 to 7 mph SSW | 15% |
| Saturday Night | 66°F | Partly Cloudy | 5 to 8 mph SSW | 7% |
| Sunday | 95°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 to 12 mph SSW | 15% |
| Sunday Night | 64°F | Partly Cloudy | 10 mph SSW | 7% |
| Monday | 92°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 6 to 13 mph SSW | 15% |
| Monday Night | 61°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 7 to 13 mph S | 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 Aug 4, 2026.