July 3: 6 PM - 11 PM
July 4: 6 PM - Midnight
July 5: 6 PM - 11 PM

Legal Fireworks:
Consumer fireworks sold at a Washington State Licensed and Whatcom County Permitted stand are allowed to be used in the county.  The Washington State Patrol has a list of legal and illegal fireworks on its website.

Illegal Fireworks:
M-80’s and larger, dynamite and any improvised, homemade, or altered explosive devices such as tennis balls or cherry bombs are illegal explosive devices. Persons in possession or using illegal explosive devices can be charged with a felony.

Sky lanterns are now allowed in Washington State when tethered (i.e. kite string or similar material). The tether must remain attached for the full duration of the flight and the lantern material must be recovered and disposed of properly. Any fire started with a sky lantern (tethered or not) is subject to Reckless Burning laws and fire code violations which can amount to both civil fines and criminal charges.