Diamanti arrived from Livorno in August and is still to establish himself in the Hammers' starting XI.
He admitted: "I'd never been to London before in my life. I left Livorno on a sunny day and when I arrived here it was cloudy. But it's OK, it doesn't rain so much and it's not so cold.
"The decision to come was half private and half a career choice. My wife is an international woman. She comes from Taiwan and I wanted to make a change in my life and have a different experience.
"Also, I wanted to improve my skills as a player and improve on the pitch. I'm learning a lot from Gianfranco Zola, he gives me a lot of advice, especially on free-kicks and shooting.
"He was one of the greatest ever in Italian football and it's a great honour to play for him."