Today is likely to be the coolest day of the week, as a trough of low pressure aligns itself with the Pacific Coast, but it will gradually warm up to seasonal temperatures during the week.
"We'll go from 5 degrees below normal to about normal," said Drew Peterson, forecast meteorologist with the National Weather Service in Sacramento.
The low pressure system accounts for the cooler weather at the start of the week. "What that is doing for us is to bring in the southwest flow from the eastern Pacific into our area," said Peterson. "Specifically in Sacramento, it is enhancing the delta breeze, and bringing in cooler, moisture marine air."
Today's high is expected to reach 86 degrees, well below the normal 91.
Monday will still be cooler than normal - the high will be 89 degrees. Tuesday will see the thermometer climb up a notch, with a daytime high of 90 degrees.
The low pressure system starts to weaken mid-week, which translates to Wednesday reaching the normal high of 91 degrees. Thursday will be slightly warmer at 92 degrees.
"August is one of our warmer months," said Peterson. "July is typically the hottest, with August the second."
The average monthly high for August is 92.2 degrees. In September it drops to 87.9 for an average max high.
"We usually have 90s in August and 80s in September,' said Peterson. "We're starting to cool off, with a bigger drop in October."
October's average monthly high is 77.9 degrees.
"When we move from August to September, it's a 5 degree drop," he said. "But from September to October, it's a 10 degree drop."