miranda, nbc bay area news. >> very dangerous. in santa rosa, another suspected serial arsonist is in jail tonight. police took a 50 we're old woman into custody today. lorraine helen martin is facing eight counts of arson. >>> the heat has heightened concerns about fire danger. but some areas have more reason to be concerned than others on. on your top left, a live look at dublin where folks are experiencing triple digit heat. san jose, still warm. san francisco, much cooler. you can see the fog rolling in. chief meteorologist jeff ranieri is tracking these major temperature extremes. >> right now we had the hottest temperature in livermore where nanette was reporting from. 105 degrees. will likely go down as the official high today. that's good enough for a new record. has not been this hot since 1973. the old record 102. keep in mind, while the tri-valley gets hot, the average high is 79 degrees. so way above average. but you can see as we mentioned, it's not hot everywhere. a huge temperature spread across parts of the bay. 71 in berkeley right now. oakland 77. hayward, 74. you had about 20, 25 miles away, tucked back in the tri-valley, 101 in livermore right now. 101