My home city is in the Mmid-eastern part of China. My home city is in the mid-eastern part of China.

There are several ways to say this, but Mideast sounds a bit strange to my ears

My home city is in the Mideast part ofcentral China. My home city is in central China.

in northern China in southern China in the eastern region of China in the western region of China

DuringIn winter, the coldest temperature here is around 6 degrees Celsius. In winter, the coldest temperature here is around 6 degrees Celsius.

Many people here spend their Chinese New Year on Hainan island. Many people here spend Chinese New Year on Hainan island.

Using "their" gives the impression that there is a special difference between what you do and what other people do. For example: I spend my Chinese New Year with my parents, while my brothers spend theirs traveling to a sunny spot. I wish they were here with the family.

I went there on the 29th of January and went back on 5thleft on the 5th of February. I went there on the 29th of January and left on the 5th of February.

I went there on 29th January and went back on 5th(left/went home/went back home) (or) stayed until February 5th. I went there on 29th January and (left/went home/went back home) (or) stayed until February 5th.

The temperature in Danzhou is always 12 degrees higher than that in my city. The temperature in Danzhou is always 12 degrees higher than in my city.

But on rainy days, I don't feel much warmer, instead I feel almost feel the same as in my city. But on rainy days, I don't feel much warmer, instead I feel almost the same as in my city.

almost describes "the same" so needs to be in front of that word

I don't feel like it is much warmer in Danzhou. I don't feel like it is much warmer in Danzhou.

Unless you are writing something very formal, it is sounds more natural to write it's instead of it is.

If it is 17 degrees in my city, it feels prettyquite a bit warmer. If it is 17 degrees in my city, it feels quite a bit warmer.

Pretty warmer doesn't work, you could say pretty warm.

If it is 17 degrees in my city, it feels pretty(a lot/a little/somewhat) warmer. If it is 17 degrees in my city, it feels (a lot/a little/somewhat) warmer.

pretty not used with comparative or superlative pretty warm pretty big pretty happy pretty old pretty good

So, if it rains a lot during the Chinese New Year, ithere is not a big difference tobetween spending the holiday on the northern part of Hainan island or in my home city. So, if it rains a lot during the Chinese New Year, there is not a big difference between spending the holiday on the northern part of Hainan island or in my home city.

So, if it rains a lot during the Chinese New Year, it is not a big difference to spend the holiday on the northern part of Hainan island or in my home city. So, if it rains a lot during Chinese New Year, it is not a big difference to spend the holiday on the northern part of Hainan island or in my home city.