It's a bit cold today. A bit 这个短语放在形容词前，表示“稍微（有点儿）”，
其他例子还有：
It's a bit warm these days. 最近天气有点儿暖和呢。
The rain is a bit big. 雨下得有点儿大。
The wind is a bit strong. 风有点儿大。