There's several factors to keep in mind when shopping for rain boots. Let's go through each:
Durability: Durability and quality go hand-in-hand in the case of rain boots because the quality needs to be stellar (especially in the outsole) to provide the traction, support, and stability needed to combat the rain. Most of us don't want the task of having to buy something over and over again because it wears fast, so durability is something to look for when shopping for rain boots.
Waterproof or not: Honestly, the whole point of a rain boot is for the boots to be water-resistant. If they are not, then it technically doesn't qualify as a rain boot because they will get ruined the minute water touches them. The boots need to be waterproof to be deemed a rain boot in our book.
Price: How much are you willing to spend? Only you can determine that answer. You can definitely get a quality rain boot for around $150 (which is the average price of the ones we listed), but there's also quite a few boots under the $100 price point (a few of which we have included as well) that get the job done. Obviously if you are looking for luxury, that means spending several hundred or even thousands.
Activity: What are you going to be using the boots for? Are you planning on having them as a "just in case" for a rainy day when you have to go to work, run errands, etc.? Are you planning on being outdoors (hiking for example)? These are questions to keep in mind as you shop because even though all of the boots we listed here are meant for the rain, if you are hitting the trails, Dior's Garden Rain Boots still probably aren't the best choice.
Height: How tall are the boots you are looking at? Do you want your boots to stop at your ankle, or do you want them to go up to your leg/calf? This is a personal preference, but it's important to pay attention to how the boots are labeled so you can know what you are getting.
Weight: The weight of the shoe sort of connects back to what you plan on using the boots for and your comfort level. For example, some of the designer boots we have listed on this are bit on the bulky/chunky side, which means they're harder to walk in. On the flip side, we've also included several lightweight options as well. Once again, it's dependent upon your comfort level.
Insulation: Some rain boots feature built-in insulation for additional warmth. If this is something that is important to you or you live in a very cold area, you might want to consider a boot that has this feature.