1 - Il gèle directly translates to it freezes, implying very cold.
2 - Il fait do soleil means it's sunny, and Il fait 35 degrés celsius means that the temperature is 35C, which is a very hot summer day. Either of these could apply to this question as they both imply that it is warm outside but to be safe I would pick Il fait do soleil.
3 - Ratatouille was invented in Nice and usually made by less wealthy farmers in the summer time when the vegetables were available, and contiues to be a very popular dish today.
