There you have some Spanish idioms about weather and my try to explain them for you.

"Después de la tormenta viene la calma" = When you are in bad times you have to think that in the future them will get better.

"Estar en el séptimo cielo" = To be extremely happy

"Nubarrones en el horizonte" = There are "Nubarrones en el horizonte" when you foresee that something bad is about to happen. 

"Hace un frío que pela" = When it is very cold.

"Haga frío o calor" = Not matter what happens, you are going to do something.

"Hace un día de perros" = When it is very bad weather.

"Llueve a cantaros" = It is raining a lot.

I hope you like them.

I'll be glad if you correct my mistakes in English.

Don't hesitate to ask any question.