SAN FRANCISCO -- Fire season opened Monday for several Bay Area counties just in time for the first major heat wave of the year -- a weather system that promises to bring sweltering triple-digit temperatures, gusty breezes and low humidity to the region by mid-week.

The Cal Fire Santa Clara Unit announced that fire season has begun for Santa Clara, Contra Costa and Alameda counties. The agency has suspended all open burning permits and was cracking down on landowners who did not maintain their property against wildfires.

Last week, Gov. Arnold Schwarzenegger instructed state fire officials to begin fining rural homeowners who fail to clear their properties of brush, trees and dry grass.

Schwarzenegger said clearing around homes was particularly important because of this year's dry conditions throughout the state.

A 2005 law required that homeowners who live near forests or grasslands increase the so-called "defensible space" around their houses from 30 feet to 100 feet.

State Fire Marshal Kate Dargan said inspectors have issued few citations to homeowners who ignore the law. Instead, firefighters have focused on educating them about the dangers of overgrown properties.

Those dangers are sure to be intensified by mid-week when the first major heat wave of the year was forecasted to begin to triple-digit temperatures to the inland areas.

According the National Weather Service, a high pressure system was building over the Pacific. Forecasters were predicting a deadly combination of soaring temperatures in the upper 90s to low 100s, extremely low humidity and gusty breezes to begin by Wednesday.