黄定的回答：

1.这段时间天气变化无常。: It's so changeable at this time of year. 2.四月里变化无常的天气: April weather. 3.这星期他脾气变化无常，所以不要惹他生气。: His temper's is changeable this week, so do not annoy him. 变化无常: constantly changing Examples: 1. 我希望你不要再这样变化无常了，快拿定主意吧！ I wish you wouldn't keep chopping and changing like this, make up your mind! 2. 那个女孩变化无常的性格让我们很生气。 The wantonness of the girl's character annoyed us.

丁乃竺的回答：

The weather is constantly changing

韩晓萌的回答：

changeable weather

毁灭者的回答：

the weather in spring changes quickly