Can weird describe the weather?

Yes.

Weird means strange and changeable.

Sometimes the weather is neither hot nor cold, but it is clearly said to be a non-raining weather, and the sun is indeed bright in the morning, but after noon, the weather begins to become gloomy, and more and more clouds gather. , it is getting thicker and thicker, and it feels like "dark clouds are pressing down on the city and is about to destroy it", which is really a bit weird.