Monday's Memorial Day holiday could be marred by weather, with thunderstorms possible in the York area in the late afternoon and an air quality alert on for the day.

York County and the rest of the Susquehanna Valley are under a Code Orange air quality alert from the Pennsylvania Department of Environmental Protection. That means that air pollution is concentrated enough to affect sensitive people, including young children, the elderly and those with asthma, heart disease or lung disease, the DEP said. People in those groups are urged to minimize outdoor exercise.

Monday will be partly sunny, with a high of 90 and low of 69, according to the National Weather Service. Showers are possible through the day, with thunderstorms possible mostly between 5 and 8 p.m.

Tuesday will be partly sunny, with showers and thunderstorms still a possibility, the forecast said. The high will be 87 and the low 64, and winds will be from the southwest at 5-9 mph.

Wednesday will be mostly sunny, with a high of 85 and low of 58, the forecast said. Winds will be from the west at 3-10 mph.

Thursday will be sunny, with a high of 77 and low of 57, the NWS said.

Friday has a chance of showers, with a high of 75 and low of 58, the forecast said.

Saturday also has a chance of showers, with a high of 70 and low of 57, the service said.