Ok, but under same temp probe position, location on patio, amt/type/precook temp of meat (2 rib racks), weather (hot), dial setting unchanged, etc, etc : one weekend after 30 minutes temp was 225, next weekend 185. 30 minutes later, first weekend 225, next weekend 190
Pretty variable
If doing a large brisket [and perhaps large laod of food], seems time could vary by many, many hours making it difficult to know when to put brisket on if having company or one wants to eat before midnite