Forecasters are warning of increased fire danger for the North Bay beginning again Wednesday when winds pick back up and humidity levels drop.

After a brief reprieve with calmer winds and higher humidity levels Tuesday, the National Weather Service has issued a red flag warning from 5 p.m. Wednesday to 5 p.m. Thursday. Drying winds out of the northeast are predicted between 15-30 mph, with gusts up to 45 mph in the hills. Humidity levels will drop back down to 10-20 percent during the day, said forecaster Scott Rowe, with overnight humidity levels rising to 30-40 percent.

Any fires that develop during that period of time will develop rapidly, the weather service warned, advising people to avoid any outdoor burning.

A red flag warning was also issued for the East Bay hills, beginning 11 p.m. Wednesday.

In Santa Rosa, air quality was declared “very unhealthy” by the Environmental Protection Agency Tuesday afternoon, with a rating of 281. A rating of 301 qualifies as “hazardous.”

A “very unhealthy” rating means those with breathing sensitivities should avoid all activity outdoors. Those without sensitivities should avoid prolonged or heavy exertion.

Wednesday’s air quality forecast calls for a slightly better rating of 153, only registering as “unhealthy.”

You can reach Staff Writer Christi Warren at 707-521-5205 or christi.warren@pressdemocrat.com. On Twitter @SeaWarren.