Learn Turkish: Mart ayında yağmur yağıyor mu?

While you can say Mart'ta, Turkish often pairs month names with ay (month) to make a compound noun. Mart ayı means "the month of March". To add the "in" suffix (-da), we need a buffer letter -n- after the compound noun, creating Mart ayında.

Why do we need the buffer letter -n- in ayında instead of -y-?

In Turkish, when you add a spatial suffix like "in" (-da/-de) to a word that already has a possessive ending (like the -ı in Mart ayı), you must use the buffer -n-. The buffer -y- is only used when adding suffixes to plain nouns that end in a vowel.

Why are there two words for rain (yağmur yağıyor)?

English uses "rain" as both a noun and a verb, but Turkish separates them. yağmur is the noun for "rain", and yağmak is the verb used for weather falling from the sky. Literally, you are asking "Is rain falling?".

Why does yağıyor use the -ıyor ending if the English translation says "Does it rain"?

The Turkish present continuous tense (-ıyor) is used for things happening right now ("Is it raining?"), but it is also very commonly used for general habits or seasonal facts ("Does it rain?"). The context of asking about the month of March tells us it is a general question.