Since 2007 I have experienced an occasional but random haunting aroma. It’s hard to describe but it elicits a nostalgic sorrow in me.
Part industrial, part water, a mix of gentle chemicals. It happens everywhere almost always in the winter.
I have tried to isolate it’s origin without success.
Now I simply welcome it’s arrival and let the waves of nostalgia flow.
Smell will certainly burst memories out from long forgotten corners of the mind, often unexpectedly. The thrift store does it to me a lot, a whiff of old perfume or discontinued laundry fragrance, of course, but also less obvious scents like a gross old bowling bag or decaying vinyl tarps.
My guess, since the OP says it happens almost always in the winter, would be ozone from static electricity, which is much more common in dry indoor environments in winter. It’s definitely a distinctive smell, kind of a sweetish and somewhat industrial, chemical odor. When I was a kid I had a train set with a transformer that used to generate a lot of ozone smell, and whenever I smell it these days it also brings me a wave of nostalgia.
Interesting. Not quite what I am trying describe but it has definite similarities.
The aroma is not location specific but it does seem to be mostly headquartered in the fall/winter seasons.
I am convinced it is either something in my body or a paranormal aroma lol.
But the water/soil thing is interesting.
This could be it lol.
Certain aromas can instantly transport me into another time with flooding memories.
It’s fascinating.
♫ Haunting, aroma!
Haunting aroma!
Who has a haunting aroma?
It’s me! ♫
Probably not what the OP is experiencing but the “haunting aroma” that comes to mind (especially in the southwest) is the smell of creosote after a rain.
I sang this to the tune of Waltzing Matilda.
As you should have. 
Awesome! Now I have a new earworm lol.
Another time AND place!
Me: Ooh, what does this old thermos smell remind you of?!
Salvation Army patron: Don’t talk to me or my son ever again.
Smells are an instant time portal transporter.
The first time I lived in Germany (1974-1975), I noticed a smell. It was usually indoors, not necessarily in homes, but in larger spaces. No one ever mentioned a smell, so I said nothing.
I forgot about it.
I returned years later (1984-1985), and the first time I noticed that smell, I remembered it from ten years before. I made a mention to another servicemember’s wife, just out of curiosity.
She knew what I as talking about.
The smell wasn’t unpleasant, and I have never noticed it in the US.
So I guess I have one of those mystery smells.
~VOW
Whenever I smell an MGB, a Willys flat-fender Jeep, or a Porsche I say, ‘Yep.’
Love, love that smell. I have an unnatural attraction to new asphalt being laid too.
I’ve been known to chase it on purpose.
I heard that the smell of fresh mown grass(well regarded and universally loved) is actually the death of the grass you’re smelling.
I like the smell 2-stroke oil.
Does something to me.
They absolutely are. I’m not sure if anyone has come up with a good explanation for why this is true, but it definitely is.
For me, the smell of pine trees evokes two completely different but equally vivid memories. The most intense is the smell of a Christmas tree when first brought into the house. As a small kid, I wanted to help my Dad set it up but mostly I just jumped around in delight. But also, our country cottage was surrounded by many pine trees, some of them amazingly big, and the faint smell of pine, especially at night or after a rain shower, was heavenly. I sometimes get faint hints of it sitting on my front porch from the evergreen shrubs.
Some time ago I put some frozen sausage rolls in the oven and after a little while I got a very distinct hit of “Christmas morning smell”. It was the pastry baking. This one is a real mystery because I don’t recall either my parents or anyone else baking things on Christmas morning, yet somehow that powerful memory smell persists!
Not at all. A well-mowed lawn is thick and healthy. You’re smelling the natural moisture from the residue that, if allowed to grow uncontrolled, would have ruined the lawn. Mowing grass is analogous to getting a haircut. No murders are involved.
Girl, you be weird! 
I totally get it!
I used to work in a steel mill and love the smell of oil and machinery.
Mystery smells are so lovely and enchanting!
I hope you get to experience it again.