There are three main factors regarding residential outdoor burning:

1. where you live (burning is always prohibited inside the city limits of Nevada City and Grass Valley)
2. which fire jurisdiction serves your location
3. whether a burn permit is required

See info below for CAL FIRE, Nevada County, and Placer County.

CAL FIRE
During certain times of the year and in certain parts of the state, residential landscape debris burning of dead vegetation is allowed. However, homeowners should always check with their local fire station or CAL FIRE station, as well as local air quality management agency before burning. Burn permits are required many places and during the dry months, CAL FIRE prohibits burning altogether.

• Cal Fire Burn Permits - https://burnpermit.fire.ca.gov/
• Cal Fire Burn Status - https://burnpermit.fire.ca.gov/current-burn-status/

IMPORTANT: CAL FIRE Burn Permits are only for within the State Responsibility Area (SRA), or where CAL FIRE has jurisdictional authority.  For information and permits required outside the SRA / CAL FIRE jurisdiction, contact your local City/County fire authority. If the status in your county is marked as "Burning Allowed", you still must confirm that it is a permissive burn day with your local air quality management agency. The contact phone numbers will appear on your permit. Violations Of Any Burning Permit Terms Are A Violation Of State Law (Public Resources Code 4421, 4422, 4423 And 4425).

NEVADA COUNTY
https://www.mynevadacounty.com/2753/Burn-Permits
To see if it is a burn day, check with the Northern Sierra Air Quality Management District.
https://myairdistrict.com/index.php/burning-info/burn-day-status/
Western Nevada County: 530-274-7928
Eastern Nevada County: 530-582-1027
Truckee Fire Protection District - https://www.truckeefire.org/burn-permit-1

PLACER COUNTY
Air Pollution Control District
https://www.placerair.org/1677/Residential-Burning
https://www.placerair.org/1885/Outdoor-Burning-Requirements