I have a sittuation:
A husband is watching the weather forecast programme with his wife in the room. It 's cool outside. The forecaster says " It may be very cold today". Then the husband says " I wish it wouldn't be so cold today".
so does the sentence "I wish it wouldn't be so cold today" which the husband has just said express a wish with a future event?
No, we just don't say it that way.
The husband is most likely to say: "I hope it isn't [cold today]."
This construction is usually reserved for habitual, ongoing actions, e.g.
"I wish he wouldn't talk like that!"
"I wish it (my car) wouldn't keep stalling."
It's not normally used for a single event in the present or future.
* "I wish it wouldn't be so cold tonight."
* "I wish my car wouldn't stall tomorrow morning" NO.
"I hope my car doesn't stall tomorrow morning." YES.
"I wish my car wouldn't stall
every morning" YES.