Many games don't really bother too much with weather conditions. It's often usually assumed that the weather is unremarkable and that it causes no particular inconvenience. That said, many games do have rules covering extreme environmental conditions such as heat and cold, which can be used to simulate the effects of extreme weather. You can also assess various penalties such as to movement or vision for inclement weather such as rain or fog.
Ultimately, though, it depends if adding such details enhances your experience of the game. Some players like little details like the weather and feel that they add interest and veracity to the make-believe world, whereas others see game-mechanical weather effects as punitive and tedious, getting in the way of the business of slaying monsters and acquiring loot.
So don't feel like you have to use weather effects in your game.
Commentary by memnarch (who has not seen the movie)
And you've also got almost as much hair as a wampa. Seriously, with hair as long as Chewbacca's is, I remember being surprised that Kashyyyk appeared as green and warm as it did. Not to mention all the water; imagine how long it would take to dry off in the humidity!
Most of our modern explosives, as far as I know, are not shock sensitive while being transported, with detonators practically being a requirement in order to actually set them off. Even things like live hand grenades that are ready to be used have a safety pin or clip to prevent them from accidentally exploding. I know Star Wars is one of the best visual examples of the "Used Future" aesthetic, but I don't think there would be even a small risk of explosion here. Even if the Resistance doesn't have a lot of resources, that's just even more reason to be careful about transporting explosives around.
Chewbacca: I say, it’s rather cold here.
Zeppo: Oh, really? You’re cold?
Chewbacca: Why yes. I am naked, you know. And I’m from a tropical planet.
Finn: Come on, we can keep warm by running.
Chewbacca: I assume these explosive charges I’m carrying are safe being jostled?
GM: Now that you mention it... <roll>
GM: You’re fine. For now.
Chewbacca: Darn. I was hoping for some extra warmth.