Newcastle, SD Weather & Growing Conditions
This Afternoon
55°F
Partly Sunny
Partly sunny. High near 55, with temperatures falling to around 50 in the afternoon. North wind around 12 mph, with gusts as high as 22 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 55°F | Partly Sunny | 12 mph N | 0% |
| Tonight | 28°F | Partly Cloudy | 5 to 9 mph NW | 0% |
| Thursday | 56°F | Mostly Sunny | 1 to 7 mph SW | 0% |
| Thursday Night | 29°F | Mostly Cloudy | 1 to 7 mph S | 0% |
| Friday | 53°F | Mostly Sunny | 3 to 7 mph NW | 0% |
| Friday Night | 29°F | Mostly Clear | 3 mph SW | 0% |
| Saturday | 58°F | Sunny | 2 to 9 mph NW | 0% |
| Saturday Night | 30°F | Mostly Clear | 3 mph SW | 0% |
| Sunday | 62°F | Sunny | 2 to 7 mph S | 0% |
| Sunday Night | 35°F | Mostly Clear | 2 to 6 mph W | 0% |
| Monday | 59°F | Sunny | 6 mph W | 0% |
| Monday Night | 34°F | Partly Cloudy | 6 mph SE | 0% |
| Tuesday | 58°F | Mostly Sunny | 3 mph SE | 0% |
| Tuesday Night | 34°F | Partly Cloudy | 3 mph N | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Newcastle, SD
Last spring frost
May 13
First fall frost
Oct 3
Growing season
143 days
Hardiness zone
4b
Explore more for Newcastle, SD: full frost dates · planting calendar · South Dakota frost dates
Climate data from the nearest NOAA station, Newcastle, Wy (17.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 5, 2026.