Tian qi

Jin tian, tian qi bu <strike>shi</strike> re. <strike>Zhe</strike> Jin tian shi yin tian. Xi wang ming tian tian qi bu cuo. <strike>Shi zenme tianqi zai Zhongguo? </strike>Zhong  guo de tian qi xian zai zen me yang ne?

PS: We don't put pin yin together.

Tianqi

Jintian, tianqi bu <strike>shi</strike> tai re. <strike>Zhe </strike>shi ge yintian. Xiwang  mingtian tianqi bucuo.<strike> Shi zenme tianqi</strike> zai Zhongguo tianqi zenmeyang ne?

天气
今天，天气不太热，是个阴天。希望明天天气不错，在中国天气怎么样呢？

Tianqi

Jintian, tianqi bu shi re. Zhe shi Yintian. Xiwan, mingtian tianqi bucuo. Shi zenme tianqi zai Zhongguo?

I guess what you wanna say is : "Today is not a hot day. It's cloudy. Hope tomorrow's weather could be fine. How's the weather in China?", is it? cuz if it is , it's better to say like this:

"Jintian tianqi bu re. Jintian shi Yintian. Xiwang mingtian tianqi bucuo. Zhongguo de tianqi ruhe ne?"