The Southwest Ohio Air Quality Agency has issued an air quality alert through Thursday night.

According to the National Air Quality Index, ozone pollutants are expected to reach the “orange” level, which is considered unhealthy for sensitive groups, particularly young children, the elderly, and those with respiratory conditions.

The alert is effective from midnight through 11:59 p.m. Thursday night. Areas covered by the alert include Butler, Clermont, Hamilton, and Warren counties in Ohio, Boone, Campbell, and Kenton counties in Kentucky, and Dearborn County in Indiana.

The National Weather Service in Wilmington advises that people carpool, bike, walk, or take the bus instead of driving alone. The NWS also recommends that individuals refuel their vehicles after 8 p.m. and mow their lawns in the evening to avoid using gas-powered lawn equipment. Also, avoid idling in carhicle, as exhaust contributes to air pollution.

What does an air quality alert mean?

• Take the bus, carpool, or walk instead of driving.

• Refuel your vehicle after 6 p.m. Do not top off while refueling, and tighten the gas cap.

• Do not idle your vehicle.

• Combine trips, or eliminate unnecessary trips.

• Keep your vehicle maintained with properly inflated tires and timely oil changes.

• Avoid the use of gasoline-powered equipment.

• Avoid the use of oil-based paints and stains.

• Never burn leaves or other yard trimmings.

• Burn clean, seasoned wood in outdoor fire pits, fireplaces and wooden stoves.

• Avoid using fire pits or fireplaces for nonessential home heating.

• Conserve electricity.

What is an air quality alert?

According to Columbia University, the U.S. Environmental Protection Agency (EPA) created the air quality index, or AQI, “to monitor and report on air quality each day and let people know about its possible health impacts.”

Over 1,000 locations in the United States monitor and record the air for four significant pollutants: ground-level ozone, particulate matter, carbon monoxide and sulfur dioxide. An air quality index level of 100 is considered safe. An AQI under 100 is good or acceptable, and an AQI over 100 is cause for concern, especially for vulnerable groups. Levels over 300 indicate hazardous conditions.

Detailed Cincinnati forecast

Some showers and thunderstorms will also occur Thursday night in Friday morning ahead of a cold front that will cross the area late tonight into Friday. This will cause temperatures to fall back a bit for the end of the week, but hot conditions will quickly rebound on Sunday.

According to a hazardous weather outlook, unseasonably warm conditions will develop through early next week in the tri-state area. The combination of heat and humidity will result in heat indices around 100 on Monday, Tuesday, and Wednesday.

Thursday: Sunny, with a high near 89. Calm wind becoming southwest at 5 to 8 mph in the afternoon.

Thursday night: Increasing clouds, with a low of around 66. Southwest wind around 5 mph becoming calm in the evening.

Friday: A chance of showers and thunderstorms before 10 a.m., then a slight chance of showers and thunderstorms after 1 p.m. Partly sunny, with a high near 85. Light and variable wind becoming northwest at 5 to 7 mph in the morning. The chance of precipitation is 30%.

Friday night: Mostly clear, with a low around 62. North wind around 5 mph becoming calm in the evening.

Saturday: Sunny, with a high near 87. Calm wind becoming east around 5 mph in the afternoon.

Saturday night: Partly cloudy, with a low around 62.

Sunday: Sunny, with a high near 96.

Monday: Mostly sunny and hot, with a high near 98.

Tuesday: Mostly sunny, with a high near 96.

Wednesday (Juneteenth): Mostly sunny and hot, with a high near 97.

Source: National Weather Service, Wilmington.

This article originally appeared on Cincinnati Enquirer: Weather: Air quality alert in effect Thursday in Cincinnati