Learn Italian: Il clima in questa capitale non è così freddo come a Londra. - The climate in this capital is not as cold as in London.

It translates to "as... as". You put così before the adjective (freddo) and come before the second part of the comparison (a Londra). You could also use tanto... quanto instead, which means exactly the same thing: non è tanto freddo quanto a Londra.

Why is it il clima? Doesn't the -a ending usually make a word feminine?

Usually, yes! However, clima is a masculine noun. It is one of several Italian words of Greek origin that end in -a but are masculine. You might remember other common ones from earlier lessons like il problema (the problem) and il programma (the program).

Why is the feminine word questa used with capitale?

Because when capitale refers to a capital city, it is a feminine noun (la capitale). Watch out, because if you make it masculine (il capitale), the meaning changes to financial capital or money!

Why do we say a Londra when the English translation says "in London"?