Is the weather of 30 degrees suitable for mountain climbing?

30 degrees is not suitable, it's too hot, it's easy to get heatstroke and it's also called a burden to carry too much water! However, if the mountain you climb is higher than 3K, it should still be ok, because as the altitude increases, the temperature will drop. Generally, 23 degrees is more suitable for leisure mountain climbing. I hope it helps you!