"天气用英语怎么说" can be translated to "How to say 'weather' in English". If you want to ask about the current weather, you can say "What's the weather like today?". If you want to ask about the temperature, you can say "What's the temperature like?". If you want to ask about the wind speed, you can say "What's the wind speed like?". If you want to ask about the humidity, you can say "What's the humidity like?". If you want to ask about the forecast for the next few days, you can say "What's the weather forecast like?" or "Can you tell me the weather forecast for tomorrow?".
