The Pennsylvania Department of Environmental Protection has issued a Code Orange Air Quality Action Day for ozone for Tuesday in Lehigh and Northampton counties.

A combination of mostly sunny skies and high temperatures in the middle 90s will likely contribute to 8-hour average concentrations of ozone in the Code Orange range on Tuesday.

The U.S. Environmental Protection Agency’s Air Quality Index provides standardized color codes for forecasting and reporting daily air quality. Green signifies good air quality; Yellow means moderate air quality; Orange represents unhealthy pollution levels for sensitive groups of people; and Red warns of unhealthy pollution levels for all.

Residents and businesses within the Air Quality Action Day areas are strongly encouraged to voluntarily help reduce air pollution by:

Driving less by carpooling or using public transportation;

Combining errands to reduce vehicle trips;

Limiting engine idling;

Refueling cars and trucks after dusk; and

Conserving electricity by setting air conditioning to a higher temperature and turning off lights that are not in use.

The latest forecast:

Tonight: Mostly clear, with a low around 65. Southwest wind around 5 mph.

Tuesday: A chance of showers and thunderstorms, mainly after 4 p.m. Some of the storms could produce gusty winds. Mostly sunny, with a high near 92. West wind 5 to 10 mph, with gusts as high as 25 mph. Chance of precipitation is 30%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Tuesday Night: A chance of showers and thunderstorms, mainly before 7 p.m. Partly cloudy, with a low around 67. West wind around 5 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Wednesday: A chance of showers and thunderstorms after 2 p.m. Mostly sunny, with a high near 91. Light west wind becoming southwest 5 to 10 mph in the morning. Chance of precipitation is 50%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Wednesday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 67. Southwest wind around 5 mph becoming calm in the evening. Chance of precipitation is 40%. New rainfall amounts between a quarter and half of an inch possible.

Thursday: A chance of showers and thunderstorms, then showers and possibly a thunderstorm after 2 p.m. High near 82. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.

Thursday Night: Showers and possibly a thunderstorm before 2 a.m., then a chance of showers. Low around 66. Chance of precipitation is 80%.

Friday: A chance of showers, with thunderstorms also possible after 2 p.m. Partly sunny, with a high near 82. Chance of precipitation is 50%.

Friday Night: A chance of thunderstorms before 8 p.m. Partly cloudy, with a low around 63. Chance of precipitation is 30%.

Saturday: Mostly sunny, with a high near 82.

Saturday Night: Partly cloudy, with a low around 63.

Sunday: A chance of showers and thunderstorms. Partly sunny, with a high near 83. Chance of precipitation is 40%.

Sunday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 65. Chance of precipitation is 40%.

Monday: A chance of showers and thunderstorms. Partly sunny, with a high near 83. Chance of precipitation is 50%.