Low temperatures could dip below freezing overnight Monday into Tuesday in the Lehigh Valley.
A low of 26 is expected overnight, and the frost and freeze conditions could kill crops or other vegetation and damage unprotected outdoor plumbing, according to the National Weather Service in Mount Holly, New Jersey. The Lehigh Valley will be under a freeze warning from midnight until 9 a.m. Tuesday.
Forecasters said a strong cold front will pass through the region Monday, bringing temperatures down. A high of 50 degrees is expected Monday, which is a big departure from the temperatures the Lehigh Valley had just days ago. Highs were in the 70s and 80s most of last week.
Temperatures should return to normal and then be above average by the end of the week. Forecasters said highs will be in the 60s and 70s Wednesday through Friday, but a cooldown and widespread rain are likely over the weekend.
Good Monday morning! Several areas are colder early this morning than originally forecast, therefore some frost to greet the early risers. A more widespread freeze is expected tonight and early Tuesday morning. Protect the cold sensitive plants! #pawx #njwx #dewx #mdwx pic.twitter.com/Dx5OA4dek7
— NWS Mount Holly (@NWS_MountHolly) April 20, 2026
“An area of low pressure may arrive during the weekend, especially for Sunday, bringing the potential for widespread showers or a period of rain,” meteorologists wrote Monday in their daily forecast discussion. “The strength and timing of the involved features however is lower confidence.”
Any rain the region gets will be beneficial. Lehigh and Northampton counties both have drought conditions, according to the U.S. Drought Monitor.
The state Department of Environmental Protection placed Lehigh County under a drought warning and Northampton County under a drought watch.
There is a slight chance of rain Tuesday night and Wednesday. Here is the extended forecast from the National Weather Service:
Tuesday: Sunny, with a high near 55. Calm wind becoming southwest around 5 mph in the afternoon.
Wednesday: A chance of showers, mainly before 8 a.m. Partly sunny, with a high near 67. Calm wind becoming southwest around 5 mph. Chance of precipitation is 30%. New precipitation amounts of less than a 10th of an inch possible.
Thursday: Sunny, with a high near 71.
Friday: Mostly sunny, with a high near 70.
Saturday: A chance of showers. Mostly cloudy, with a high near 61. Chance of precipitation is 50%.
Sunday: A chance of showers. Mostly cloudy, with a high near 62. Chance of precipitation is 40%.