Before making any decisions about what's best for you, we need to answer some basic questions about water-resistant and waterproof technology.
Does "water resistant" mean "waterproof"?
When you see that a jacket is "water resistant," it rarely means that it's "waterproof". Waterproof apparel features waterproof technology that water-resistant apparel does not. However, it's important to keep in mind that some brands and vendors have higher standards than others. The truth is, unless it's made of a non-porous material like rubber, no jacket is 100% waterproof. And, since rubber is non-porous, it's also not breathable -- or comfortable.
See the sections below on sealed seams and waterproof ratings to get a better idea of what "waterproof" and waterproof ratings actually mean.
What's the difference between waterproof and water resistant?
The difference between water resistant and waterproof is all in the construction. Water-resistant jackets and pants usually have a DWR (durable water repellent) finish on the exterior that repels moisture and keeps you dry in light rain or snow. If the jacket features a waterproof breathable membrane, laminate or other comparable waterproof technology, then it is usually considered waterproof. A waterproof jacket or pair of pants with a waterproof breathable membrane as well as all seams sealed is more waterproof than one with just a waterproof breathable membrane and no (or just critical) seams sealed.
To learn exactly how waterproof breathable membranes and laminates keep you dry, check out this post about the science of waterproof technology.
What are sealed seams?
Even with a waterproof breathable membrane to protect you from moisture, you can still get wet if the seams of your jacket aren't sealed. Stitched seams are a major weak point in the construction of waterproof gear; they host a ton of tiny holes in the fabric where water can penetrate. That's why your waterproof jacket (or pants) should be either critically or fully seam sealed. "Critically seam sealed" means only the upper body of the garment has sealed seams, leaving some seams vulnerable to leakage. "Fully seam sealed" means all seams in the jacket are sealed for maximum water tightness.
There's a couple of ways seams can be sealed to keep water from sneaking through. "Taped seams" are sealed with a waterproof tape that provides a layer of protection from moisture. "Welded seams" are seams that are joined without stitching -- and even more resistant to water than taped seams. Welded seams utilize glue or sonic bonding to join pieces of fabric without the bulk or vulnerability of stitched seams.
What do waterproof ratings mean?
As previously mentioned, there are varying degrees of "waterproofness." When you're shopping for a waterproof jacket, you'll notice that waterproof ratings are often listed along with waterproof technology features. These ratings are reflections of how the fabric fared in a waterproof test called the "Static-Column test." In the Static-Column test, a tube with a 1-inch diameter is placed on top of the fabric and slowly filled with water. At the first sign of leakage, the water's height is noted and becomes the waterproof rating. So, waterproof jackets with a waterproof rating of 5,000mm succumb to water leakage before a jacket with a 20,000mm rating.
It's important to keep in mind, however, that you may not need a really high waterproof rating on your jacket. Take a look at the table below to figure out how high you need your jacket's waterproof rating to be.
Should I get a water-resistant jacket or a waterproof jacket?
Like every gear decision, it depends on what you intend to do in the jacket. As you shop, you'll notice that there are a lot of really nice water-resistant jackets out there. Some of them might feature Gore Windstopper® technology, which offers breathable protection against wind in addition to providing some protection from moisture. Others might be flexible soft shells or warm down jackets. Just because a jacket isn't waterproof doesn't mean it's not a quality jacket that could work really well for you.
So, let's get back to which jacket you should pick: water resistant or waterproof? If you're buying a jacket to ski or snowboard in, you need a waterproof jacket. If you're buying a jacket specifically for rainy days in town or on the trail, you need a waterproof jacket. If you're buying a jacket for walks, hikes, climbs, rides or daily life in generally dry conditions, a water-resistant jacket will work well for you.
The bottom line is that you need a quality waterproof jacket when you know you'll likely encounter sustained time in wet weather. Generally, people who spend any amount of time enjoying the outdoors need at least one waterproof jacket in their closet (or pack).
Want even more details about waterproof gear? Check out our comprehensive waterproof guide.