WWUS71 KPHI 181810 NPWPHI URGENT - WEATHER MESSAGE National Weather Service Mount Holly NJ 210 PM EDT Mon May 18 2026 DEZ001-PAZ102-190900- /O.EXB.KPHI.HT.Y.0001.000000T0000Z-260521T0000Z/ New Castle-Eastern Chester- Including the cities of Wilmington, Kennett Square, and West Chester 210 PM EDT Mon May 18 2026 ...HEAT ADVISORY IN EFFECT UNTIL 8 PM EDT WEDNESDAY... * WHAT...Heat index values up to 98. * WHERE...In Delaware, New Castle County. In Pennsylvania, Eastern Chester County. * WHEN...Until 8 PM EDT Wednesday. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS...Record setting high temperatures are quite possible through Wednesday, with maximum heat indices nearing 100 degrees during peak heating each afternoon. Given the intensity of this early season stretch of heat and humidity, we are not acclimated to it yet and therefore impacts could be greater if precautions are not taken. Showers and some thunderstorms arrive later Wednesday afternoon and evening which will break this early season heat. PRECAUTIONARY/PREPAREDNESS ACTIONS... Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. && $$ NJZ012-013-020-027-190900- /O.EXB.KPHI.HT.Y.0001.000000T0000Z-260521T0000Z/ Middlesex-Western Monmouth-Ocean-Southeastern Burlington- Including the cities of Freehold, Wharton State Forest, Jackson, and New Brunswick 210 PM EDT Mon May 18 2026 ...HEAT ADVISORY IN EFFECT UNTIL 8 PM EDT WEDNESDAY... * WHAT...Heat index values up to 98 expected. * WHERE...Western Monmouth, Middlesex, Ocean, and Southeastern Burlington Counties. * WHEN...Until 8 PM EDT Wednesday. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS...Record setting high temperatures are quite possible through Wednesday, with maximum heat indices nearing 100 degrees during peak heating each afternoon. Given the intensity of this early season stretch of heat and humidity, we are not acclimated to it yet and therefore impacts could be greater if precautions are not taken. Showers and some thunderstorms arrive later Wednesday afternoon and evening which will break this early season heat. PRECAUTIONARY/PREPAREDNESS ACTIONS... Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. && $$ NJZ007>010-PAZ060>062-101-103-105-190900- /O.EXA.KPHI.HT.Y.0001.000000T0000Z-260520T0000Z/ Warren-Morris-Hunterdon-Somerset-Berks-Lehigh-Northampton-Western Chester-Western Montgomery-Upper Bucks- Including the cities of Washington, Oxford, Morristown, Collegeville, Bethlehem, Flemington, Chalfont, Perkasie, Honey Brook, Easton, Somerville, Reading, Allentown, and Pottstown 210 PM EDT Mon May 18 2026 ...HEAT ADVISORY IN EFFECT UNTIL 8 PM EDT TUESDAY... * WHAT...Heat index values up to 97 expected. * WHERE...In New Jersey, Morris, Somerset, Warren, and Hunterdon Counties. In Pennsylvania, Berks, Lehigh, Northampton, Upper Bucks, Western Chester, and Western Montgomery Counties. * WHEN...Until 8 PM EDT Tuesday. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS...Record setting high temperatures are quite possible through Tuesday, with maximum heat indices of 95 to near 100 degrees during peak heating through Tuesday afternoon. Given the intensity of this early season stretch of heat and humidity, we are not acclimated to it yet and therefore impacts could be greater if precautions are not taken. Showers and some thunderstorms arrive Wednesday afternoon and evening which will break this early season heat. PRECAUTIONARY/PREPAREDNESS ACTIONS... Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. && $$ NJZ015-017>019-PAZ070-071-104-106-190900- /O.EXT.KPHI.HT.Y.0001.000000T0000Z-260521T0000Z/ Mercer-Gloucester-Camden-Northwestern Burlington-Delaware- Philadelphia-Eastern Montgomery-Lower Bucks- Including the cities of Morrisville, Camden, Cherry Hill, Mount Holly, Trenton, Lansdale, Moorestown, Doylestown, Philadelphia, Media, Norristown, and Glassboro 210 PM EDT Mon May 18 2026 ...HEAT ADVISORY NOW IN EFFECT UNTIL 8 PM EDT WEDNESDAY... * WHAT...Heat index values up to 98. * WHERE...In New Jersey, Mercer, Camden, Gloucester, and Northwestern Burlington Counties. In Pennsylvania, Delaware, Eastern Montgomery, Lower Bucks, and Philadelphia Counties. * WHEN...Until 8 PM EDT Wednesday. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS...Record setting high temperatures are quite possible through Wednesday, with maximum heat indices nearing 100 degrees during peak heating each afternoon. Given the intensity of this early season stretch of heat and humidity, we are not acclimated to it yet and therefore impacts could be greater if precautions are not taken. Showers and some thunderstorms arrive later Wednesday afternoon and evening which will break this early season heat. PRECAUTIONARY/PREPAREDNESS ACTIONS... Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. && $$ Gorse