Learn Turkish: Ekim ayında deniz soğuk mu? - Is the sea cold in October?

In Turkish, it is very common to include the word ay (month) when naming a month. Ekim ayında literally means 'in the month of October'. While Ekim'de is also perfectly correct, adding ayında sounds very natural and is widely used.

What are the suffixes attached to ay in ayında?

It starts with ay (month). To link it to Ekim, we add the compound noun suffix ı, making Ekim ayı (October month). To say 'in', we add the locative suffix da. When adding a location suffix to a compound noun, Turkish requires the buffer letter n between them. So: ay + ı + n + da becomes ayında.

Why is the question particle mu instead of mı or mi?

The question particle changes based on 4-way vowel harmony. It always looks at the last vowel of the word right before it. Since the last vowel in soğuk (cold) is u, the particle must become mu to match it smoothly.

Could I put the word deniz at the beginning of the sentence instead?