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.
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.