Hamilton had a "scary" month for smog in May and there's a chance this summer won't look much better.

The city had 11 smog advisory days last month, the same number we had all last year.

Environment Canada's chief climatologist, Dave Phillips, said May was warmer than normal and there wasn't a lot of steady rain to scrub the air. "You had all the ingredients of producing bad air days," he said.

Phillips said 2005 was "the summer from hell," when the city had 31 hot days with temperatures above 30 C, temperatures almost two degrees warmer than normal and precipitation about normal but not enough to clean the air. There were 45 smog days that year.

Last year was better. It was warm, with 15 hot days with normal rainfall, often at night, and only 11 smog days.

"When it is warmer, with less rain, it leans that way. There is a strong hint, a greater chance, you're going to get more smog days," he said.

Phillips said that while smog was bad in 2005, last year was far more healthy because there was more westerly air instead of air from the industrialized Ohio Valley. Environment Canada is calling for a warmer than normal summer. "I wouldn't be a bit surprised if it was a lot like last year," he said. However, indications are that there will be less rainfall than normal, which could mean more smog, he said.