Allentown’s Halloween forecast calls for partly cloudy skies and a high near 61, after a clear, upper-30s morning. Temperatures are expected to fall quickly after sunset, reaching around 34 overnight. Northwest winds near 5 mph and no expected rain should leave daytime plans largely dry; skies are forecast to turn partly cloudy overnight as winds ease.
A chilly night, then a milder start to the week
The evening cooldown is the main consideration for trick-or-treaters and anyone staying outside after dark. A jacket should help as temperatures drop, with the coldest conditions expected before sunrise Sunday.
Sunday’s forecast is partly sunny with a high near 64 and a low around 37. Mostly sunny skies and a high near 66 are expected Monday, followed by a partly sunny Tuesday with a high near 68, according to the National Weather Service.
Forecasts and climate normals answer different questions
The chilly overnight forecast describes a specific stretch of weather, not what is typical for Halloween. NOAA’s National Centers for Environmental Information says U.S. Climate Normals are calculated over 30 years and provide climate context rather than a prediction for an individual day. The available context does not give Allentown’s normal temperatures for this date, so it cannot establish how unusual the forecast high or low is.
