Learn Spanish (Spain): Hace una semana que llueve. - It has been raining for a week.

In Spanish, when an action started in the past and is still happening right now, you use the present tense. The structure hace + [amount of time] + que + [present tense verb] is the standard way to say that an action "has been happening" for a certain amount of time.

Could I use the present continuous and say hace una semana que está lloviendo instead?

Yes, you can use the present continuous here, and it would be perfectly correct. However, using the simple present tense like llueve is extremely common and often preferred in Spanish for this structure, unlike in English where "it rains for a week" sounds incorrect.

Is there a way to say this without starting the sentence with hace?

Yes! You can reverse the order by putting the main verb first and using desde hace. The sentence would become Llueve desde hace una semana. Both versions are natural and mean exactly the same thing.

Why do we use the verb hacer here?

The verb hacer is used idiomatically in Spanish to talk about elapsed time. While English expresses this with prepositions like "for", Spanish builds a phrase that translates literally as "it makes a week that it rains". You just have to memorize hace as the fixed verb for these time expressions.