There are “No Fireworks” signs posted in all the parks in the California county where I live. I heard that if I go to a different county, I might be able to set off fireworks on the Fourth that aren’t allowed here. Is that true?
As long as you follow the permitting city or county's other ordinances as well. Cities or counties that permit safe and sane fireworks (described below) might have restrictions on where and when they can be discharged. A local ordinance might prohibit setting off fireworks near residences or during certain hours. Always check the local government ordinances, which can usually be found on the city or county website or by calling their offices.
This article discusses fireworks laws in California cities and counties. For more information about California state fireworks laws, see Are Fireworks Legal in California?
For information about fireworks sales and use on Native American reservations or tribal lands, see Fireworks Sale and Use on Indian Reservations.
The State of California restricts the type of fireworks that private citizens may buy, possess, or discharge. State law distinguishes between two types of fireworks: dangerous fireworks (those prohibited without a permit) and "safe and sane" fireworks (those permitted without a permit).
State law prohibits sale, possession, or use of dangerous fireworks without a permit. The list of dangerous fireworks can be found in section 12505 of the California Health and Safety Code. Examples include skyrockets, roman candles, chasers, firecrackers, and sparklers more than 10 inches long or a 1/4 inch in diameter.
State law permits the sale, possession, and use of safe and sane fireworks without a permit. The law doesn't list out what types of fireworks fall under the definition of "safe and sane." The State Fire Marshal identifies and certifies what constitutes "safe and sane" fireworks. You can find a link to a document that lists safe and sane fireworks on the State Fire Marshal's website. (Items for sale can also be identified by a seal (shown here).)
While state law permits safe and sane fireworks, it still regulates them. Among other regulations, state law restricts the dates of sales of safe and sane fireworks and prohibits sales to minors. It also allows local governments to enact stricter regulations or outright bans in certain cases.
(Cal. Health & Safety Code § 12500 and following (2020).)
California's state fireworks law permits cities and counties to prohibit or regulate (beyond the state law restrictions) the sale, use, or discharge of safe and sane fireworks. Many local governments in California restrict or prohibit the use of safe and sane fireworks within their city or county borders.
The Cal Fire website notes that over 300 communities permit safe and sane fireworks use and provides a link to the list of communities. Always double-check the information provided in the list by looking up the city or county government website, as information can become quickly out of date.
And be aware that if your city or county bans use of fireworks, it might also ban possession or storage of them. So even if you purchase them legally in one city and intend to use them in a city where it's legal, you still might violate your local ordinance by bringing them back to your residence to store them for the Fourth of July celebrations.
(Cal. Health & Safety Code § 12541; Ventura v. City of San Jose, 151 Cal.App.3d 1076 (1984).)
State regulations of fireworks differ by state. Some states permit local governments to enact stricter regulations, while others don't. In many cases, you can find information on websites for your city or county government, the local fire department or police, or state fire marshal.