Hallam, PA Weather Forecast
York County, Pennsylvania
Seven-day outlook
41–70°F across the weekThe week runs between 42° and 70°, with today 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 Hallam forecast
Hallam sits at 40.0024°N, 76.6042°W in York 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
- York County
- Coordinates
- 40.0024°N, 76.6042°W
- Population
- 2,774 · 2023 estimate
- Land area
- 0.666 sq mi
Place data from the US Census Bureau. Coordinates are the Census internal point for Hallam, 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 Hallam?
The nearest Doppler radar is KLWX (Sterling, VA), 85 miles to the SSW. 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 Hallam its center is about 7,500 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 KTHV · York Arpt on the ASOS/AWOS network, 16 miles away. Far enough that "current conditions" for Hallam is an educated reading of somewhere else, worth knowing before you plan around a single temperature.
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 Hallam
- Hellam, PA2 mi
- Springettsbury, PA4 mi
- Lower Windsor, PA5 mi
- Marietta, PA5 mi
- East Donegal, PA6 mi
- Columbia, PA6 mi
- East Manchester, PA6 mi
- Red Lion, PA7 mi
Elsewhere in Pennsylvania
PhiladelphiaPittsburghAllentownReadingErieUpper DarbyAll Pennsylvania forecasts →