Most planets suffer from occasional storms. During a storm, your hazard protection will drop much faster than usual. Take shelter during storms if possible.
Some planets have extreme wheater. Your exosuit will warn you when you set foot upon such a world. hazard levels are much higher on these worlds, and storms are more frequent. Hazard Protection Upgrades are strongly recommended before exploring such planets.
However, such worlds offer rewards to the brave explorer. Resource deposits are worth considerably more.
Activated forms of the stellar metals sell high prices, and can refined into vast stores of Chromatic Metal.
Storm Crystals can be found on extreme weather planets. These are highly valuable rare resources, and can only be harvested during an active storm. Search for them using the Analysis Visor.