Colby Young has posted some information, on the IronOak Games website, about how the weather systems in For the King will impact gameplay:

We pride ourselves on For The King’s procedural game system, the world is randomly generated, all locations are placed unpredictably so having a dynamic weather system with it’s own agenda is another procedural element that can add to the chaos. A rain storm isn’t just a visual element but it comes with it’s own set of mechanics. For example it will wash away the accumulating poison in the overworld, it will put out fires or scare away some types of enemies. Not all effects are beneficial though, both rain and sandstorms will make your characters awareness rolls more difficult. Awareness is a crucial stat that prevents enemies from ambushing you. On the flip side some weather can aid the player when trying to get the jump on enemies as well.

Moving throughout the overworld is done by rolling action points and weather will affect the result of these values. Nice days are pleasant on the senses and they also aid the player by granting bonus action points which can offer additional strategy options while on your adventure. Bad weather will hinder you and alter your plans. it might be a better idea to set up camp and wait for the sun to come out instead of risking your safety in the middle of a vicious storm.

For the King continues to impress, both in terms of its visual design and in terms of the depth of gameplay it aims to feature.