Learn Spanish (Spain): Hoy hace buen tiempo.

In Spanish, you don't usually say the weather "is" good or bad. Instead, you use the verb hacer (to do or to make). So, hace buen tiempo literally translates to "it makes good weather." This is a standard phrase you just have to memorize when talking about the weather!

Why is it buen and not bueno?

The regular word for "good" is bueno. However, when it comes directly before a masculine, singular noun (like tiempo), it drops the final "o" and becomes buen. You will see this happen with a few other common words too, like un instead of uno.

I learned that tiempo means "time". Does it also mean "weather"?

Yes, exactly! Tiempo is used for both "time" (like passing time) and "weather". You can usually tell which one it means based on the context. When it is paired with hace, it is almost always talking about the weather.

Could I put hoy at the end of the sentence instead?

Yes, you can. Hace buen tiempo hoy is also completely natural and correct. Spanish word order is quite flexible with words that tell you when something happens.