Whither Weather?

Over on the GeePlus, Steven Menteer asks: How do you make weather meaningful both in terms of story and game mechanics?

He’s asking this in the 5e group, but I’m going to answer mostly generically here. Story-wise:

1. Weather Reflects the Story: dark, heavy clouds hang oppressively over the lands of the tyrannical evil baron. Mischievous autumn winds catch up the motley leaves in a wild and playful dance through the streets of the halfling village. For miles around the dragon’s lair, the land is barren, the wells dry, the creeks choked with dust, and even the warmth of the sun is sucked away by a persistent haze, until only a dull, bloody glow permeates the veil of dust.
2. Weather as Antagonist: this can be implied, as in the stories of Jack London, or some degree of literal, as in Caradhras in The Fellowship of the Ring or the darkness in Veins of the Earth. Nature is trying to defeat you somehow and the weather is one of its tools to do so. Passes will be snowed in, damp wood refuses to light or only allows weak, smoky fires, deep fog hides the movements of enemy troops, ice breaks underfoot, rocks or even entire trees fall on you, snow and mud reveals your tracks and slows your pace, pollen clogs your nostrils and stings your eyes, gales howl or winds refuse to blow and becalm your ship… The possibilities are endless here.
3. Weather as a Weapon: like above only possibly more limited. Lots of “epic” critters have Regional Effects they can invoke along these lines, such as the kraken’s control weather ability and the chilly fog or swirling blizzards that surround a white dragon’s lair. Druids and other spell-slingers can also mold the weather with their spells aggressively.
4. Weather that Marks the Passage of Time: spring rains, muggy summer nights, crisp autumn evenings and icy winter mornings help set the scene and let your players know that they’re exploring a living, breathing world. And you don’t need to stick with the standard weather patterns either. You can have exaggerated weather patterns (“Winter is coming.”) or more extreme weather patterns (dry vs. rainy season of the Serengeti, tornado season in the Great Plains, the monsoons of India and Arizona, etc.) and the cultural events that surround them.

As for rules, 5e makes this pretty easy. Even if you don’t use the exhaustion rules on page 291 of the PHB, it’s easy to include the effects of weather as advantage or disadvantage on a roll. Heavy rain or howling winds or smothering fog impede your perception checks. Rain or snow can obscure footprints. Strong winds can push arrows and javelins off target or diminish their effective range. Being forced to sleep in the open while bands of cold rain sweep over the moors could prevent the PCs from enjoying the benefits of a long rest. If you’re feeling really nasty, persistent rain could soak the PCs belongings, ruining maps or mildewing spell scrolls (a survival check could dictate how well the PCs protected their belongings from the insidious damp).

That all said, I probably wouldn’t invoke rules on weather unless it served your game. This sort of thing is a no-brainer in survival-focused Old School play, but if you’re all about the super-heroic epic conflict, I’d probably not even bother with the weather except as set-dressing unless it was actively being involved in things by some power interested in what the PCs were doing or attempting to thwart. Weather-as-nuisance is a thing that happens in real life and totally fits when the PCs are trying to scrape a living from a harsh and uncaring world. Weather-as-nuisance is just annoying when the PCs are all about thwarting the Arch-lich’s plans to replace the High Queen with a transformed red dragon right in the middle of her coronation ceremony.

Art by Pierre Auguste Cot.