阴天比晴天凉快一点。

Yīntiān bǐ qíngtiān liángkuai yìdiǎn.

Cloudy days are a bit cooler than sunny days.

阴天的时候，我喜欢在家看书。

Yīntiān de shíhou, wǒ xǐhuān zài jiā kànshū.

When it is cloudy, I like to read at home.

明天要是阴天，我们就不去公园了。

Míngtiān yàoshi yīntiān, wǒmen jiù bù qù gōngyuán le.

If it is cloudy tomorrow, we won't go to the park.