Parts of Connecticut will see slightly elevated pollution on Wednesday and Thursday with the air quality index expected to reach "moderate" levels, officials say.

Wednesday will see moderate levels of ground-level ozone in several communities, including Bridgeport, Greenwich, Madison, New Haven, New London and Groton, Stratford and Westport, according to AirNow, the federal government site that provides air quality information across the country.

"We're forecasting some air quality exceedances on Thursday and Friday (due to southwesterly winds and warmer temperatures)," said Mikayla Rumph, a spokesperson for the U.S. Environmental Protection Agency in New England.

"Also, we're forecasting that Connecticut will have ozone transport (cross-state air pollution) from Long Island Sound on Thursday and Friday as well," she added.

AirNow's forecast map also showed some moderate air quality on Thursday in southwestern Connecticut. The areas that will be affected include the southwestern corner from Greenwich to around Danbury.

Unlike ozone in the upper atmosphere, which forms a shield from the sun's ultraviolet rays, ground level ozone can be harmful to people and the environment. It's the main component in smog, according to the EPA.

The gas is made up of three oxygen atoms, and is formed when pollutants and sunlight react together. The pollutants sources include cars, power plants, industrial boilers, refineries and chemical plants, according to the EPA's website.

Unhealthy levels of ozone most commonly occur on hot, sunny days.

That's in line with the forecast through the end of the week. Wednesday began sunny with highs expected to reach up to around 80 in parts of the state. After increasing clouds and a chance of showers Wednesday afternoon, sunny skies are expected on Thursday.

Thursday and Friday are expected to see highs in the 80s, with some areas expected to see temperatures reach near 90 degrees, according to the National Weather Service. Showers and storms are also likely on Friday, as a cold front moves into the area, the agency said.

The state Department of Energy and Environmental Protection said air quality will be good to moderate on Wednesday.