When this mod is installed with Scorchful (https://www.curseforge.com/minecraft/mc-mods/scorchful), being exposed to rain (with an umbrella!) will still increase your wetness, which doesn't make a lot of sense, since the umbrella is blocking the rain. Don't know how, but the umbrella from Artifacts (https://www.curseforge.com/minecraft/mc-mods/artifacts) prevents rain from getting you wet.

Wetness is displayed on the hud, as a background for the hearts.

artifacts-fabric-9.5.5.jar
originsumbrellas-1.5.6.jar
frostiful-1.0.9.jar