What is the ruling on speaking with a girl about ordinary topics such as age, circumstances, weather, and so on?

Addressing a non-mahram woman is not permissible except under specific conditions: that it is for a need, with the woman observing the legal hijab, the absence of seclusion (khalwa), and the woman not speaking in a soft or alluring manner. This is based on the Almighty's saying: (And when you ask [his wives] for something, ask them from behind a partition) and His saying: (then do not be soft in speech [to men], lest he in whose heart is disease should covet). Addressing a girl about matters like age, weather, and the like is not a necessity, and it could be a means to fall into what is forbidden.