Start with the real problem
A hiking rain jacket has to balance water protection, breathability, fit, ventilation, and the conditions in which you will actually move. No fabric can remove the heat generated by a hard climb.
In practice
Check hood adjustment, sleeve movement, hem coverage, pocket placement, and how the jacket fits over your insulating layer. A jacket that works over a T-shirt may fail when worn over a fleece.
Where judgment matters
For active hiking, pit zips or other ventilation features can be more valuable than a marketing number. For cooler, steady rain, simple waterproof protection may be enough.
What can go wrong
The mistake is buying a jacket solely from its waterproof rating without considering movement and sweat.
A simple pre-trip test
Wear the jacket with your pack and normal layers. Reach overhead, bend, and adjust the hood before deciding it fits. Check hood adjustment, sleeve movement, hem coverage, pocket placement, and how the jacket fits over your insulating layer.
Field note
One useful question for Choosing a Rain Jacket for Hiking: Waterproofing, Breathability, and Fit is what problem would justify replacing your current item. If the answer is only that the newer model looks better on paper, keep using the equipment you already understand until there is a practical reason to change.
