Darby, PA Weather Forecast
Delaware County, Pennsylvania
Seven-day outlook
46–72°F across the weekThe week runs between 46° and 72°, with tomorrow the warmest day of it. There is no real trend across it: one day looks much like the next. Every day in the outlook stays 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 Darby forecast
Darby sits at 39.9210°N, 75.2611°W in Delaware County, Pennsylvania. 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
- Delaware County
- Coordinates
- 39.9210°N, 75.2611°W
- Population
- 10,614 · 2023 estimate
- Land area
- 0.842 sq mi
Place data from the US Census Bureau. Coordinates are the Census internal point for Darby, 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 Darby?
The nearest Doppler radar is KDIX (Philadelphia, PA), 45 miles to the E. 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 Darby its center is about 3,100 ft above ground. That is comfortably inside the useful range. The lowest scan passes low enough over Darby to show rotation in the part of a storm where tornadoes actually form.
The closest instrument actually measuring the air is KPHL · Philadelphia Intl on the ASOS/AWOS network, 3.8 miles away. Close enough that its readings are, for practical purposes, the conditions in town.
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 Pennsylvania observing network as of this build.
Forecasts near Darby
- Yeadon, PA1 mi
- Collingdale, PA1 mi
- Sharon Hill, PA1 mi
- Aldan, PA1 mi
- Lansdowne, PA2 mi
- East Lansdowne, PA2 mi
- Clifton Heights, PA2 mi
- Glenolden, PA2 mi
Elsewhere in Pennsylvania
PhiladelphiaPittsburghAllentownReadingErieUpper DarbyAll Pennsylvania forecasts →