A dip in temperatures and ozone levels this weekend is expected to improve the Valley's air quality, which was unhealthy for much of the region this week.
Air quality also should benefit from lower levels of particulate matter and diminishing smoke from the Sheep fire in Sequoia National Forest and Kings Canyon National Park, said Jaime Holt, spokeswoman for the San Joaquin Valley Air Pollution Control District.
"It wasn't all that great," Holt said of the Valley's air quality, "but it's getting better."
Air quality today is expected to be moderate for Fresno, Madera, Kings and Tulare counties, she said.
A few drops of rain accompanied muggy conditions in the Valley on Friday, said Carlos Molina, meteorologist with the National Weather Service in Hanford.
Fresno's high Friday was 91.
The weekend Valley forecast calls for highs in the low 90s today with a 20% chance of isolated showers from midday to early evening.
Temperatures will drop into the mid-80s on Sunday.
A strong cold front is expected to move through the region Sunday night and into Monday, Molina said.
Monday's highs will be in the upper 70s.
Normal highs this time of the year are in the mid-80s, Molina said.
Overnight lows are forecast in the mid-60s tonight before dropping into the 50s the next few days.