Newcastle, WY Weather Forecast
Weston County, Wyoming
Seven-day outlook
33–60°F across the weekThe week runs between 36° and 60°, with Saturday the warmest day of it. The second half leans cooling, and Wednesday is the coolest day in it. Monday is the wettest day, peaking near 71%. 5 of the 7 days stay dry.
Forecasts come from the National Weather Service's own computer models, and current conditions from the nearest reporting weather station. Both are served through the weather API. A forecast is guidance, not a warning, and anything the Weather Service has actually issued is on the live map.
The written summaries on this page are generated from the forecast data above, not by a meteorologist. Each sentence is a reading of the same numbers you can see, and no forecaster has reviewed them.
About the Newcastle forecast
Newcastle sits at 43.8503°N, 104.1965°W in Weston County, Wyoming. The forecast above is drawn for that point from the National Weather Service's own computer models: a seven-day outlook, and a finer-grained one covering the next eighteen hours where it reaches, and the radar and alert panels show what the Weather Service has out over the area right now.
- County
- Weston County
- Coordinates
- 43.8503°N, 104.1965°W
- Population
- 3,326 · 2023 estimate
- Land area
- 2.561 sq mi
Place data from the US Census Bureau. Coordinates are the Census internal point for Newcastle, and the forecast is for that location, not for every address inside the city limits, and a large city can have real weather differences from one side to the other.
How well can the network see Newcastle?
The nearest Doppler radar is KUDX (Rapid City, SD), 71 miles to the ENE. A WSR-88D's lowest routine scan sits half a degree above horizontal, and the earth curves away beneath it, so by the time that beam reaches Newcastle its center is about 5,700 ft above ground. That is far enough out that the beam has climbed above the lowest few thousand feet. Storm structure aloft is visible; a shallow circulation near the ground may not be, and a warning here can arrive before anything looks dramatic on the radar picture.
The closest instrument actually measuring the air is KECS · Newcastle/Mondell Arpt on the ASOS/AWOS network, 6.2 miles away. Near enough to be representative on most days, though a summer thunderstorm can soak one and miss the other entirely.
Beam height is the standard 4/3-earth approximation for the 0.5° scan and assumes normal refraction; it is where the center of the beam is, not its edges, and unusual temperature profiles bend it. Radar siting from the NWS WSR-88D network, station positions from the Wyoming observing network as of this build.
Forecasts near Newcastle
- Lead, SD41 mi
- Hot Springs, SD47 mi
- Spearfish, SD48 mi
- Summerset, SD49 mi
- Rapid City, SD51 mi
- Sturgis, SD52 mi
- Box Elder, SD58 mi
- Belle Fourche, SD59 mi
Elsewhere in Wyoming
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