FADING SUMMER FINALLY TO BOIL.

Byline: Kerry Cavanaugh Staff Writer

It was nice while it lasted. In fact, it was so nice, August seemed more like April. But September will not be so gentle.

Angelenos have been basking in long stretches of mild, mid-80 degree weather. For the 30 days through Monday, Los Angeles was on average 3 1/2 degrees cooler than normal, National Weather Service officials said Tuesday. Burbank was about 2 1/2 degrees cooler than normal.

Thank the marine layer and June gloom that stuck around through July, keeping temperatures in the San Fernando Valley two degrees below normal and continuing the trend in August.

``Typically you see this in June, and then by July and August you see loads of sun there,'' said Byron Miranda, meteorologist with KCBS (Channel 2). ``Without the clouds in the morning we're going to see some intensive heating.''

Indeed, the first day of September is bringing triple-digit heat and fire warnings, although temperatures should moderate a little over Labor Day weekend.

August was cool. September will be cruel.

From Aug. 1 through Monday, Los Angeles was below its norm of an 84-degree high, a low of 65 and an average daily temperature of 75 degrees.

August in Los Angeles has been slightly cooler than normal for a few years now. August 2003 was half a degree below normal and August 2002 was 4 1/2 degrees below normal.

``For whatever reason, for the last seasons we've had fairly mild summers along the coast,'' said National Weather Service meteorologist Bruce Rockwell, although summer will officially continue through Sept. 21.

It's not just Los Angeles. Cities in Wisconsin, Mississippi, Texas and Illinois all posted new record low temperatures in August, according to national Climatic Data Center.

Only Yakutat, Alaska, reached a new all-time maximum temperature on Aug. 15. It was a balmy 88 degrees.

July in the San Fernando Valley also was 2 degrees cooler than normal, while downtown was 0.3 degrees warmer than the 60-year average of 69 degrees.

``This is the coolest summer I can remember for a number of years,'' said Kevin Davis, seasonal aquatics director overseeing East San Fernando Valley city pools.

``I've noticed that at my area pools, it's a little slower than in past years. We've had plenty of kids, but we haven't been as slammed as much as in other years.''

Temperatures swung widely, however, during August, when triple-digit heat was recorded early in the month in the Valley. But compare that to Saturday, Aug. 21, when Valley residents practically shivered with a high of 77 degrees. Several other days, the thermometer hit only a mere 81 degrees.

Still, ``I'm not seeing anyone in parkas on the beaches,'' joked Garth Canning, a captain in Los Angeles County government's Lifeguard Division, who was surveying Manhattan Beach on Tuesday.

``You have days when all of Los Angeles is looking to escape to the beach, and we haven't had those days. That doesn't mean we're not going to see them in September.''

Indeed, meteorologists are looking for temperatures of more than 100 degrees in the valleys today, with strong winds expected this morning. Low humidity and an already-dry landscape have put firefighters on alert and triggered new smoking and campfire restrictions in the forests.

Kerry Cavanaugh, [phone]

kerry.cavanaugh(at)dailynews.com