毛毛雨。
Máo máo yǔ
Hair hair rain.
毛毛雨 = drizzle, beautiful expression, already beginner-memorable
外面在下毛毛雨，带把伞比较好。
Wài miàn zài xià máo máo yǔ, dài bǎ sǎn bǐ jiào hǎo
Outside is drizzling, better to bring an umbrella.
比较好 = comparatively better = 'might as well'
下着毛毛雨呢，别看着小，淋久了也会湿透的。
Xià zhe máo máo yǔ ne, bié kàn zhe xiǎo, lín jiǔ le yě huì shī tòu de
It's drizzling, don't think it's small - if you're out long you'll get soaked.
湿透 = soaked through; references how drizzle deceives
More Chinese (Mandarin) Weather Phrases