I don't own a Weber but do have a Pit Boss, 1+- a hour if low temp smoking in 60-70 degree weather, drop the temp and pellet usage rises, a better question is will it give a amount of smoke you will be happy with? I always advise folks to try to sample food off of 1 before they buy. the smoke profile is a lot lighter than other forms of smoking, not a bad thing, the pellets burn very clean the higher you run the temps up, I always run mine at low temp/high smoke for a few hours before I kick the temp up.