There was a sudden drop in temperature last night.

昨晚气温骤降。

Scientific instruments inside the volcano's cracks record a sudden drop in temperature, and much less volcanic gas.

在山缝中的科学仪器记录到了温度的陡然下降，和火山气体的减少。

Sometimes there is a sudden drop in temperature and it gets cooler.

有时温度突然下降，变得凉爽。