When talking about raining outside in / on the street. Which preposition should I use, in or on?
There is no rain in the street. (meaning that it is not rainy now in the street)
or
There is no rain on the street. (meaning that it is not rainy now on the street)
The rain is neither on nor in the street. This is not a matter of grammar, but how "rain" works. Once it is on the street it isn't rain anymore, it is a puddle or a stream.
Rain is type of weather. The rain is not normally restricted to just the street. You would just say "It's raining". Or "It's raining outside"
If you absolutely need to clarify that rain is falling you could use "rain is falling in the street" or "falling on the street" both would reasonable.
It is possible to use "rain" as a synonym for "rainwater". It would be clearer to use "puddle" for this sense.
I would not use either example to mean what you describe. I would just say, "It isn't raining now" or "It isn't raining out there."
[updated at the end to address prepositions of place and include another interpretation]
But let me paraphrase your examples to clarify a distinction between the prepositions in an on.
It's raining in the streets.
Here, "the streets" (notice the plural) is another way of saying "out in the city" or "in an urban environment." This sets a mood that reminds me of detective stories and flim noir, which may not be your intent.
It's raining on the street.
The important image here is that the rainwater is hitting the pavement/roadway and getting it wet or washing something away.
There's rain on the street.
This does not necessarily mean that it's currently raining, only that there is water from the sky now standing, flowing, making puddles, etc. on the pavement/roadway.
There's rain in the street.
This means almost (if not exactly) the same thing as "There's rain on the street." For "on the street" I'm more likely to imagine puddles and for "in the street" I'm more likely to imagine flowing in the gutters. Not everyone has the same imagination.
What do you mean by "the street" i.e., the wide, paved surface (object, concrete, flat/2D) or the space delimited by trees, buildings, etc. (location, abstract, space/3D)?
It's raining in the streets.
This uses "the streets" in an abstract sense as in the phrase "Don't play in the street." It is physically impossible to play inside the flat object but it is possible to move within the space as a location. Although this example makes some sense, it is an unusual way to phrase things. I would avoid saying this except possibly in a literary or poetic work.
There's rain in the street.
This implies the location bounded by the gutters and/or curbing and water from the sky flowing through or within the space. Some people might not agree with this interpretation, so you may want to avoid this construction by rephrasing.
It's raining on the street.
Here again, the emphasis is on the effect of the rain on a surface, getting it wet or washing something off.
There's rain on the street.
As mentioned in other answers, the word rain here would not mean falling rain but merely rainwater that has collected on the surface of the pavement/roadway.
This last interpretation is the only one where your example makes sense but its meaning is not what you intend based on your description. "There is no rain on the street" could mean that the surface of the road is dry. Even then, since it might be wet from sources other than rainwater, it would be clearer to say, "The street is dry."
You could say either. Rain "in the street" suggests the afterproducts of rain, perhaps puddles or coursing water from a heavy rainstorm; water "on the street" suggests that the road surface is wet or moist (which you might be better to simply state directly).
Use "raining" which is the verb of to rain, or "it has started to rain in the street", the form you use in your question rain is a noun so I dont believe it is the correct form to convey the meaning you requested.
Raining "on" the streets would be more correct. This would be concerning rain water making the streets wet. It would also snow on the street"
It gets a little more ambiguous as the volume increases: "The snow is laying in the street" "The snow is laying on the street" (Either is ok) But if the snow is volumous, the "in" version would be more appropriate.
"_____ in the streets" would be preferred for other things though. "The people are marching in the streets" "There will be dancing in the streets" "There's flooding in the streets"
Given these observations, I would say that "in" is used for things that can block vehicular traffic, whereas "on" would be used to indicate a condition where travel is unimpeded.
