Will my stuff get wet if I get caught in the rain? What would be a good waterproof bag if not this one?

This bag is about as waterproof as you can get. I have used it as a cooler and after about an hour, the ice got the bag wet. But in the rain, your stuff should be safe and dry for a while as long as you get out of the rain in a reasonable time.

Hey JamarT, The ballistics nylon is a general term for any nylon fabric made with a "ballistic" weave, usually a 2x2 or 2x3 "basket" weave. There are several weights, referred to as "denier" by the industry which may be used for the weave of this bag, the weight/denier gives the weave it's durability. Generally, 1050 w/d is the most bombproof and likely used in this application, though Timbuk2 doesn't specify (here or their website). Either way, Ballistics nylon is tough and tightly woven and should REPEL not seal out moisture and rain. The fabric could easily be treated with a water-proofing product like Nikwax to improve the water-repellent characteristics after the fabric became grimy and dirty from repeated use, streets are nasty, especially after the rain. You might try looking at the Timbuk2 Classic Bag; it has a waterproof lining (not sure if the Mullet does) and has several favorable reviews attesting to its durability and water-repellent characteristics. Either way, this bag will allow water in if you submerge it, so stay on the streets and trails and you internal items should be fine, avoid any rivers 5 feet deep running down Main Street - SCI.