The material you choose for your outdoor canopy will dictate exactly what weather conditions it will be able to withstand. Cheaper materials will obviously be less durable and may only really serve a cosmetic purpose, while more expensive materials will be specially designed to resist the elements.
Polyester canopies are the most common. They are relatively durable and water resistant, with higher denier polyester offering much more protection than lower denier polyester. Keep in mind, this material isn't completely waterproof, so it's not recommended for individuals living in areas experiencing high rainfall. Also, the UV protection provided by polyester is pretty minimal, unless it's treated with a special UV protection solution.
Polyethylene canopies are like an improved version of polyester. They're specially treated to offer substantial UV and rain protection, making them a popular choice for car canopies and permanent features likes gazebos or pergolas. However, this increased resistance does make it quite a bit more expensive than other, less durable options.
Vinyl canopies are the most resistant on the market. Not only are they UV resistant and completely waterproof, but they are also usually flame retardant - while we don't expect you to be accidentally setting fire to your outdoor canopy anytime soon, it's a reassuring fact. However, all of this means that vinyl canopies are the most expensive on the market, and the fabric is often very heavy due to being so durable.