Most of the Bay Area was under a heat advisory Tuesday as temperatures did not cool off as much as expected overnight, according to the National Weather Service. <\/p>\n
Around 11 a.m., NWS Bay Area said a heat advisory would be in effect until 9 p.m. for all of the Bay Area except the immediate Pacific Coast zones and San Francisco. <\/p>\n
Temperatures were expected to be in the mid-90s to low-100s. <\/p>\n
“Mid\/upper level cloud cover across the region \u2026 combined with temperatures forecast to reach the 90s (potentially exceeding 100 deg F in the warmest interior spots) across the interior made for widespread Moderate HeatRisk,” the NWS said.<\/a> <\/p>\n Heating up today! A Heat Advisory is in effect through 9 PM Tuesday for interior areas, with highs in the mid-90s to low 100s. Excludes San Francisco & immediate Pacific coast. Drink water and take breaks! \u2600\ufe0f\ud83e\udd64 #CAwx<\/a> #BayAreaWX<\/a> pic.twitter.com\/zdilNdidNQ<\/a><\/p>\n \u2014 NWS Bay Area \ud83c\udf09 (@NWSBayArea) July 21, 2026<\/a><\/p>\n Tuesday is expected to be the hottest day of the week, and people should be wary of hot conditions causing heat illness outdoors.<\/p>\n While parts of the Bay Area felt humid, a San Ramon Valley Fire official said it can create a false sense of security when it comes to fire danger. <\/p>\n “The humidity that you feel can create a false sense of security to the fire danger, and it’s the heat that can pull moisture from the plants, which increases fire danger,” Deputy Chief Joe Bradley said.<\/p>\n Wildfire smoke expected to impact air quality<\/p>\n An air quality advisory <\/a>was issued Tuesday due to smoke from the Little Fire<\/a>, which has burned 950 acres near Pleasanton. <\/p>\n Bay Area Air District officials are expecting smoke from the fire to affect the air quality in the East Bay. <\/p>\n “Pollution levels are not expected to exceed the national 24-hour health standard. A Spare the Air Alert is not in effect,” the air district said.<\/p>\n