Quelques possibilités:
"Small talk"
Example: You can make small talk with these phrases: "How's the weather?", "Did you see the game last night", "It sure is hot outside"
"Everything and nothing"
Example: "We talked all night about everything and nothing."
This phrase means a lot of talking happened, but nothing too deep or personal was discussed.
"Anything and everything"
Example: "Our conversation lasted for hours as we talked about anything and everything."
This phrase means no topic was off limits and the conversation may have gotten deep and/or personal.
"To ramble on"
Example: " We rambled on all night".
This phrase means we kept talking and talking with possibly no direction.
If you could give some examples of how the phrase "La pluie et le beau temps" would be used in context that might help narrow down which one to use or maybe there is a better equivalent.
Hope that helps.