Can weather be an uncountable noun?

Weather means "weather", which is an uncountable noun and cannot be preceded by an indefinite article. For example, we can only say that in such good weather, we can't say that in such good weather. For example:

The weather has changed. The weather has changed.

Note that although you can't add an indefinite article before weather, weather uses the plural when it means "all kinds of weather" or "whatever kind of weather". For example:

She went out rain or shine.

Weather refers to the meteorological conditions in a specific area at a specific time.

Climate generally refers to a long period of time, such as the weather conditions of a season.

Driver, the climate is good for her health. A dry climate is good for his health.