It's warm today, suitable for going to the mountains.

It's sunny today, which is very suitable for going to the mountains.

It's warm today, which is very suitable for going to the mountains.

The weather can't be said to be warm, but it can be said to be sunny, sunny and the like, or simply get rid of "warm".

You can also say:

The temperature is warm today, which is very suitable for playing in the mountains.