The wrod for 'weather' is 'tempo' which is an abbreviation of
'tempo atmosferico', but everybody always use the short form.
'clima' is exactly the same as 'climate', that is the weather over a long period of time, so 'il clima di oggi' is not a good expression.
The weather is clear and very pleasant:
Il tempo e` sereno e molto gradevole.
Il tempo e` sereno e la temperatura e` gradevole.