Is this lawn fungus? How do I treat it?

Doesn’t look like it, but dollar spot produces a white spider web mess. However, only in the morning and disappears when the dew dries.

Also I don’t see anything wrong with turf - no yellow or brown spots.

Is is stuck to grass or it is windborne?

It seems like it is stuck in grass. Though not in picture, there are also mushrooms. I have had mushrooms over my lawn in previous years too, but never had any problems with it. This year though I am seeing these white things along with mushrooms.

Also to note is that it rained heavily in the last few days.

Are you sure it's not just like those fluffy pollen things from some trees? Just thought I would ask in case, cause it kinda looks like it has a seed in the fluff.

Easiest way to differentiate between mycelium and cotton wood seeds (what I think this is) is to grab the "cotton" mass and roll it between your fingers. If it disappears it is mycelium. If you are left with a small ball of cotton in your fingers, it is a cotton wood seed. Also, dont confuse mycelium with spider mites webs. Mycelium will be much more dense than a spider mite web.

Thanks guys for your inputs. It does turn out to be cotton wood seeds. As @Supergrass mentioned, I roll that between fingers and got a small cotton ball. I also noticed later that there were many such things flying around in neigborhood.

You guys saved me time and money on going through a fungicide program.