Some other common expressions:
How is the weather today? आज मौसम कैसा है?
How the weather would be today? आज मौसम कैसा रहेगा?
It's very cold today. आज तो बहुत ठण्ड है.
By 'touch and go', if you mean to say that it's a bad weather with rain, thunder etc. you can say आज मौसम बहुत खराब है.
आज = today
मौसम = weather
बहुत = very/too
खराब = bad
है = is