Problems with Nikon D3100 in low light?

Whenever I shoot low light in the streets there's clouding around street lights, lamps, brights areas even when i have the correct exposure. Tried changing iso, shutter and aperture but it won't go away it's real annoying

A UV filter might solve your problem.

Try shooting your "night" scenes at twilight. If you wait until dark and open the exposure to try to capture the general scene, the lights are going to be way overexposed.
http://www.kenrockwell.com/...timing.htm

Using a UV filter to help is completely untrue. A UV filter blocks UV radiation. They were used with film cameras because film was sensitive to UV light. However, digital sensors are not, therefore it can't make any difference. In fact, just by adding an additional lens, you could easily get more flare making matters worse.

Can you post a sample photo so we can see what's going on? It just might be a normal type of distortion.

The sensor can't be the problem, so it sounds like your lens is dirty or you may have a cheap filter on the front of it. Clean the front/rear elements with lens cleaner and a microfiber cloth. If you've got a filter on the lens, clean both sides of it too. Try taking a set of shots with and without the filter to see if that's causing the problem.

Don't like bokeh? Try shooting further away.