As the region sweltered through its 24th day exceeding Code Orange air quality Wednesday, forecasters say there's no relief in sight.

"Temperatures have been unforgiving," said Brian Carr, director of communications for the Atlanta-based Clean Air Campaign.

The Georgia Environmental Protection Division said the air quality index for Wednesday in the Atlanta area that includes Hall County was 106, meaning the weather is unhealthy for sensitive groups. Any readings above 100 are unhealthy for children, people sensitive to ozone and those with heart or lung diseases.

To put the unhealthy air in perspective, EPD officials say there were 25 days above Code Orange last year, 17 in 2009, 31 in 2008 and 53 in 2007.

Carr said the hotter- and drier-than-normal weather of this summer are behind the unhealthy air that can cause breathing problems and eye irritation.

"We would advise people to limit their exposure to bad air and tell them not to exert themselves," Carr said.

Carr said about half of all air pollution comes from vehicle emissions, so the Clean Air Campaign suggests voluntary actions to keep air quality from getting worse. Among these are carpooling, taking transit and biking.

Education in recent years, Carr said, has contributed to fewer Code Red days when the index goes above 160 and the air is unhealthy for everyone. There hasn't been a Code Red day since July 2009, he said.

EPD monitors and reports on air quality levels, making forecasts depending on weather patterns, traffic conditions and other factors. The Clean Air Campaign then issues Smog Alerts to the public.

To stay informed about air quality, people can visit the campaign's website, cleanaircampaign.org, to sign up to receive Smog Alerts via email.

So far this year, the region has had 45 90-plus degree days, said Dan Darbe, forecaster at the National Weather Service office in Peachtree City.

Typically, the average high is 89 from late July to mid-August before the high drops to the mid 80s later next month, Darbe said.

"We definitely have a ways to go," Carr said.

Associated Press contributed to this report.