Arguably some people might think the what version is more appropriate when the speaker is specifically interested in knowing what the weather actually is (or perhaps will be, later in the day). Conversely, the how version might be more likely if what the speaker wants to know is how the addressee feels about the weather.

0 You can think of it this way: weather is usually referred to as "it" Today it is cold so, the singular be verb gets used It was cold today. I wish it wasn't so cold. I wish it weren't so cold today. is still understandable.

Both foggy and snowing are weather conditions. Roughly speaking both foggy and snowing mean the sky is filled with fog or snow respectively. Snowy, however, is not a weather condition. Snowy is a more general term than snowing, meaning things are covered with snow. It can be snowy and snowing or it can be snowy but not snowing.

0 I wish the weather would improve tomorrow=grammatical. I wish the weather were going to be good tomorrow.=grammatical For it to be grammatical with regard to the future, you have to introduce the expectation, which is expressed using the past continuous subjunctive or regular past continuous to express an unreal situation in the present.

In the sentence "Today it is rainy" it does not refer to today, but to the weather (implicitly). Though in normal speech it's not uncommon for the "it" part to be omitted because it's common knowledge what your talking about. So in short today refers to a day, and a day can not be rainy (technically).

6 I'm trying to say: I don't like the weather today because it is ____. (rainy / raining) I have to carry an umbrella for ____ (rainy / raining) weather. Should I use rainy or raining? Also, what is the common rule for using these words?

How is tomorrow's weather forecast looking? How is the weather looking tomorrow? In both sentences, the addition of looking alters the meaning of the sentence enough that it's clear it's not asking about methods of forecasting the weather. To address a comment about forecast versus forecasted: Forecast is both a verb and a noun.

Usually, when we talk about the weather tomorrow, we use a verb, NOT a noun. We don't say: *Tomorrow is rain. (ungrammatical, uses a noun) Talking about the present The verb RAIN usually uses the word it as a subject: It's raining today. In this example we see the Present Continuous is raining. This is because the raining action is happening NOW.

He need worry about the weather today. He needs worry about the weather today. Mostly we see the use of 'need' as modal verb in negative or interrogative sentences where it takes bare infinitive w...

We say, for example, "It looks like rain today", meaning something along the lines of "From what I can see [of the weather right now], I think it will probably rain later". By the same token, "What does the weather look like?" would usually mean "Based on what you see now, what do you think the weather will be like later today?".