April weather, rain and shine both together.

一边日出一边雨，晴雨无常四月天。

《新英汉大辞典》

April weather is changeable.

四月的天气是易变的。

youdao

In March and April, the weather is much less predictable.

三、四月份的天气非常不好预测。

《牛津词典》

Most climbers make the trip in late April and May when weather conditions are the least severe.

VOA: special.2010.06.30

But he brushed off concerns about the flagging attendance, citing poor April weather and the economy as contributing factors.

WSJ: Steinbrenner Likes What He Sees

But at least they can point to cold April weather and the low initial expectations that came with back-to-back 90-loss seasons.

FORBES: Where Do Rays Go From Here?

Iglu-Dorf Zugspitze is open from 31 December to mid-April, weather conditions permitting.

BBC: Five European winter boltholes