fromEnglish Grammar Today
Weatheris an uncountable noun:
We had niceweatheron Monday for our trip to the coast.
Not:We had a nice weather on Monday.
Theweatheris always hot around the time of my birthday.
If we want to talk about an individual period of weather, we can usespell:
We had a beautifulspell of weatherfor about a week, and then it rained for two weeks non-stop!