Weather is something we all experience and mostly ignore in our RPG campaigns.
I put weather events in my random encounter tables time and again but mostly unless it's really extreme I ignore it in gaming. Which is odd since in real life I pay a lot of attention to it and it impacts me a great deal.
I walk to the park with my youngest son a few times a week. This park is about 2.5 miles away and there are 3 different routes I can take. One is longer and hard with lot's of sun, one is moderate with some sun and the other is a tiny bit longer than the second but with less sun. So depending on the temperature and time of day I take a different route.
If it's over 80 and sunny I end up tired from this walk by the time I get back home. I drink about 1200 ml of water unless it's 90+ in which case I've been known to drink over 2000 ml of water to walk about 5 miles. Lucky for me there is public water access on the route so I get away with using my 800ml water bottle.
If it's cooler I drink about 400ml of water in that 5 mile walk and don't feel tired when I get home. The walk is typically 10 minutes faster each way on the shortest route when it's cooler compared to the same route when it is hot.
So depending on sun, temperature and humidity a walk of about 5 miles takes me 80 to 110 minutes (we do play at park for 1/2 to 1 hour in addition) and I drink 400-2000+ ml of water.
I just have to wonder how much water would be consumed by 5 fighting men in armor and 3 guys without armor trying to carry as much food and gold as they can manage?
On the other end of the extreme I've gone winter camping. We snowshoe only a short distance and camp with shelter as skimpy as a tarp lean-to behind a big rock serving as a wind-break (we big rocks near us so it was a great wind-break).
On one trip it was cold. The snow was 2'-4-' deep and camp was only about an hour from our car up a ridge. The previous week it had been warm so every little bit of wood we could find was was waterlogged and frozen, we made a fire that was grossly inadequate but tolerable for the night. I did mention it was cold right? The temperature with wind chill was under -30F, it was 8F with the water above the fire until we lowered them to where they should have caught fire. When we were cooking dinner the meat was freezing to our knives one guy absent mindedly licked his knife off and it froze to his tongue a little bit. We each brought a big loaf of bread but ignored them during the trip as they were really back-up food, each froze solid. One guy brought a container of orange juice and vodka that froze enough it was just vodka with a hint of orange flavor. It was cold. You could hear the wind coming from miles away and it would go from uncomfortable to painful 4 or 5 times an hour.
Across the valley over the tree line we watched boulders of snow the size of houses crash down the mountain side and break apart filling the area beneath it with a sudden snowfall, that served to explain the occasional flurry we were having on our side.
I woke to a beautiful sound and sharp pain, the moisture in my breath was freezing on the tarp over my head and falling back down onto my face. That morning we heated water for tea and couldn't get it much over 50F and boy oh boy was that nice and war. Everyone but me got a tiny bit of frostbite, I had the worst gear actually so I was extra careful and made a point of eating and drinking a lot and paying lot more attention to how I slept (not to mention my cold-weather strip down and redress habits when winter camping ). It rose to 11F by mid morning and we cut the trip short because the wood was burning poorly (we all smelled like smoked sausage because of the smoke), on that walk out we all opened our clothes down to our bottom layer because it was so warm snow shoeing out after sleeping in a deep-freeze.
Ever since that trip I still notice cold weather but I'm oddly tolerant; this past winter when I was standing in hip-deep snow scraping it off my roof I couldn't help but reflect how pleasant and relatively warm it was.
It would have been physically impossible to wear metal armor on that trip. Without snowshoes there would have been nothing resembling travel and no way in hell we could have traveled near or above the tree-line without getting trapped or killed by falling snow.
Weather matters in real life. How do we get it to matter in our RPG campaigns?