ABC30 Meteorologist Madeline Evans said visibility is on the lower side Monday morning as the smoke settles over the Valley floor.
Fresno, Madera, Merced, and Kings counties have unhealthy air qualities for sensitive groups. Meanwhile, Tulare County's air quality is unhealthy for all.
AIR QUALITY TRACKER: Track air quality levels in Central California
Residents are warned to limit the amount of time you spend outdoors and to keep your windows closed.
Ash was seen falling at Sierra High School in Tollhouse Monday morning, and the moon had an orange hue due to the smoke.
Winds will pick up in the Sierra Nevada from an approaching low-pressure system that could fuel the current Creek Fire.
Westerly winds about 10 to 15 miles per hour, gusting to 30 miles per hour at a time, are also expected Monday afternoon. Northeasterly winds at 35 to 45 miles per hour will pick up through Tuesday.
ABC30's Madeline Evans says temperatures will drop quite a bit by Wednesday, but even with the cooler temperatures, there is still fire danger through most of the week with low humidity and gusty winds.
PHOTOS: Stunning images from the Creek Fire