Sacramento and much of Northern California suffered through a sixth consecutive day of triple-digit temperatures today, and Redding and Red Bluff reached a record high for Aug. 13, topping out a 112 degrees.

That was 1 degree above the previous record of 111 degrees, set in 2002 in Redding and in 1933 in Red Bluff, said a meteorologist with the National Weather Service in Sacramento.

In Sacramento, a high of 104 degrees was reported at Executive Airport and 107 degrees downtown, falling short of the respective records of 109 and 111 degrees for the date.

Much the same is forecast for Tuesday. "It's going to be another really hot day," said Robert Baruffaldi, a National Weather Service meteorologist in Sacramento.

While the Sacramento Valley sweltered, afternoon thunderstorms and lightning sparked several small fires in the Tahoe National Forest. Forest officials reported two fires north of French Meadows Reservoir east of Foresthill, one near Old Man Mountain north of Interstate 80 at Big Bend, one east of Jackson Meadows Reservoir in the central part of the forest and one near the Cedars about five miles south of Norden. All were less than an acre and in remote locations.

Isolated thunderstorms were expected to continue this week on the east and west sides of the Sierra, with possible dry lightning strikes along with gusty winds.

The weeklong heat wave statewide led the California Independent System Operator, which runs much of the state's interconnected network of power plants and transmission lines, to call a Flex Alert for Tuesday. Consumers are urged to conserve energy, avoiding use of appliances during peak hours of late afternoon and evening, particularly between 4 and 6 p.m.

Baruffaldi said the outlook for the middle of the week remains uncertain. Some forecasters expect triple-digit highs to continue until the weekend. Others see signs that an increased Delta breeze might provide a break Wednesday or Thursday before topping 100 again on Friday.

Baruffaldi said Sacramento's record for hot weather streaks, consecutive days of 100 degrees or higher, is 11 days, set in 2006.

Editor's Note: This story has been changed from a previous version to correct the fact that Red Bluff's high temperature set a record for Aug. 13.

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