How is the weather the day after next day?
How is the weather the day after tomorrow?
What is the weather like the day afer tomorrow?
what is the weather like the day afer next day?
这几种说法都可以.
总之问天气如何有两种表达方法：How is the weather
What is the weather like
“后天”也有两种表达方法：the day after next day
the day afer tomorrow