Studying coordinate sentences I find in alphadictionary.com the following about the meaning of То..., то...
"This conjunction indicates an alternation of things, states, and actions. Remember that both of these particles are unaccented and so are pronounced [ta]. The closest correlate of this conjunction in English is first . . . then, as the following examples demonstrate.
То Таня, то Лена дразнили бедного Володю.
First Tanya, then Lena would tease poor Volodya.
For me: Now Tanya, then Lena (in turns) would tease poor Volodya
Лена то дразнила, то утешала бедного Володю.
Lena would first tease then comfort poor Volodya.
For me: Sometimes Lena would first tease, sometimes comfort poor Volodya
Весной там то холодно, то жарко.
In the spring it is first cold then hot there.
For me: The weather there is very variable in spring: suddenly it is cold, suddenly it is hot.
"
It is surprising for me this temporal sequence: "firstly... then..." that is not present in any dictionary, since, for example "Там то идёт дождь, то идёт снег" should be translated (according with the dictionaries) as "There sometimes it rains, sometimes it snows" or "There now it rains, then it snows", but not having this temporal meaning. More widely it would be said (I think): "The weather there is very variable, sometimes it rains, sometimes it snows".
What do you think about it? Thanks.