The Strickland Summer in January Picnic is an annual picnic/propane barbeque held by the employees of Strickland Propane. Presumably it usually takes place in the Arlen City Public Park. It is only seen in "Snow Job."
The picnic starts when a torch is passed down a line of Strickland Propane employees. The last person, usually Hank Hill, lights a propane grill with it, which ignites propane-powered lights.