Learn Spanish (Latin America): Por suerte no llovió.

Por suerte is a fixed expression meaning 'luckily' or 'fortunately'. While Spanish often uses por to indicate the reason or cause of something, it is best to simply memorize this as a set phrase.

Our current lesson is about por si (just in case). How is por suerte related?

Both expressions use the preposition por, but they have different meanings. Por suerte states a fortunate fact ('luckily'). Por si introduces a precaution, such as bringing an umbrella por si llueve (in case it rains).

Weather is usually described using the imperfect tense, like llovía. Why is llovió in the preterite here?

You use the imperfect (llovía) to describe ongoing background weather, like 'it was raining'. Using the preterite (llovió) here treats the weather as a single, completed event within a specific timeframe, as if saying 'luckily it did not rain at all during the event'.

Why is there no word for 'it' before no llovió?

Weather verbs in Spanish, like llover (to rain), are impersonal. Unlike English, which requires the dummy subject 'it' to say 'it rained', Spanish simply uses the third-person singular verb on its own without any pronoun.