Thornton, CO Weather Forecast
Adams County, Colorado
Seven-day outlook
39–64°F across the weekThe week runs between 40° and 64°, with tomorrow the warmest day of it. The second half leans cooling, and Monday is the coolest day in it. Monday is the wettest day, peaking near 55%. 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 Thornton forecast
Thornton sits at 39.9204°N, 104.9414°W in Adams County, Colorado. 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
- Adams County
- Coordinates
- 39.9204°N, 104.9414°W
- Population
- 144,922 · 2023 estimate
- Land area
- 36.504 sq mi
Place data from the US Census Bureau. Coordinates are the Census internal point for Thornton, 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 Thornton?
The nearest Doppler radar is KFTG (Denver, CO), 23 miles to the ESE. 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 Thornton its center is about 1,300 ft above ground. That is about as close as radar coverage gets in the United States: the lowest scan is still near the ground when it reaches Thornton, so low-level rotation and the leading edge of a gust front show up on it. Thornton is closer to its radar than 81% of US cities.
The closest instrument actually measuring the air is KEIK · Erie Muni on the ASOS/AWOS network, 8.5 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 Colorado observing network as of this build.
Forecasts near Thornton
- Northglenn, CO2 mi
- Federal Heights, CO5 mi
- Broomfield, CO6 mi
- Westminster, CO7 mi
- Commerce City, CO8 mi
- Brighton, CO8 mi
- Erie, CO10 mi
- Lafayette, CO10 mi
Elsewhere in Colorado
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