Temperature is probably the biggest factor missing from a UWP for standard planets. But since temperature varies depending on atmosphere, altitude, longitude, season, etc all on one planet, it's kinda hard to make up weather based on so little data. Earth's average temperature is about 15 C, but hardly anyone experiences that for long. I'm in the desert right now, and temps daily range from near freezing at night to ~20 C during the day. Flash flooding in a desert should be pretty rare (although it does happen!). I like RogerD's suggestion of making it part of the story depending on the planet. Warning players that a big storm is coming might give them ideas or mess up their plans if they don't take it into account.
