Около полудня на бульваре стало шумнее, чем утром.

Around noon, it became noisier on the boulevard than in the morning.

Breakdown of Около полудня на бульваре стало шумнее, чем утром.

• на: on
• стать: to become
• чем: than
• утром: in the morning

Questions & Answers about Около полудня на бульваре стало шумнее, чем утром.

Why is it около полудня, and why is полудня in the genitive?

Около means around / approximately / near, and when it refers to time or location, it normally takes the genitive case.

So:

• полдень = noon
• около полудня = around noon

This is a fixed grammar pattern:

• около часа = around one o’clock
• около дома = near the house
• около пяти минут = about five minutes

So полудня is genitive singular because около requires it.

Why is it на бульваре and not на бульвар?

Because this phrase answers the question where?, not to where?

• на бульваре = on the boulevard / at the boulevard → location
• на бульвар = onto the boulevard / to the boulevard → direction

After на, Russian uses:

• prepositional case for location: на бульваре
• accusative case for motion toward a place: на бульвар

Here the sentence describes what was happening there, so the location form на бульваре is needed.

Why does the sentence use стало?