四年级下册英语中，常见的介绍天气的句型有：

1. It's (描述天气的形容词) today. 例如：It's sunny today.（今天是晴天。

）2.The weather is (描述天气的形容词). 例如：The weather is cold.（天气很冷。）3.How's the weather today （今天天气怎么样？）4.What's the weather like today （今天天气如何？）5.It's a (描述天气的形容词) day. 例如：It's a rainy day.（这是一个雨天。）6.The weather is (描述天气的形容词) in (地点). 例如：The weather is hot in summer.（夏天的天气很热。）7.It's (描述天气的形容词) now. 例如：It's cloudy now.（现在是多云。）