The town of Weed gets its name from the founder of the local lumber mill and pioneer Abner Weed, who discovered that the area's strong winds were helpful in drying lumber. In 1897, Abner Weed bought the Siskiyou Lumber and Mercantile Mill and 280 acres (1.1 km2) of land in what is now the City of Weed, for $400. By the 1940s Weed boasted the world's largest sawmill.
On September 15, 2014, the "Boles Fire" spread through the town driven by 40-mph winds. The fire started behind the Boles Creek Apartments in the central part of Weed at approximately 1:30pm and within 4 hours quickly spread to over 200 acres (81 ha). Evacuations were immediately ordered, and a shelter was first set up at College of the Siskiyous, but as fire headed towards the college, the evacuation center was relocated first to the Siskiyou Golden Fairgrounds in Yreka, then to Yreka and Mount Shasta High Schools, then to the Armory in Mt. Shasta.
Over 200 structures were damaged or destroyed, including two churches, the elementary school, high school, and Roseburg mill. The schools and mill sustained only minimal damage to outbuildings. About 7,678 Pacific Power customers in both Weed and Mt. Shasta lost power as a result of the fire.
The town of Weed gets its water from the Beaughan Spring. The water is piped directly to homes.
In September 2016, the New York Times reported French billionaire Pierre Papillaud demanded that Weed give up its Beaughan Spring spring water source so that Papillaud's bottle water company could have more water to sell. Disconnecting from Beaughan Spring would leave Weed without public water.