Learn Spanish (Latin America): Tenemos un retraso por el clima.

In this sentence, por shows the cause or reason for something (because of / due to). Since the weather is the reason for the delay, we use por. You would use para if you were talking about a goal or a destination.

I thought por meant 'through' or 'for'. Can it translate to 'because of'?

Yes! While por often describes movement through a place or the duration of time, it is also the standard preposition for 'because of' when explaining why something happened.

Wait, shouldn't words ending in '-a' be feminine? Why is it el clima?

Most words ending in '-a' are feminine, but there are exceptions. Many Spanish words ending in '-ma' are actually masculine. This is why we say el clima (the weather), el problema (the problem), and el idioma (the language).

Could I say 'Tenemos un retraso porque el clima'?

No, because porque means 'because' and must be followed by a full phrase with a verb (like porque el clima es malo - because the weather is bad). Since el clima is just a noun, you must use por, which translates to 'because of'.