This happened to me several times, the first when I was about 10 years of age, and several times thereafter.
A strong, hard rain occured, and when I went outside, I smelled something in the air and felt really energized. Not only that, my mood improved.
Has anyone else felt such a thing?
Does anyone have an explanation?
Thanks.
I have no explanation but I do notice after a heavy rain, the air feels ‘cleaner’ and therefore nicer to breathe.
Absolutely no cite whatsoever, but a long, long time ago somebody told me that negative ions are psychoactive and that this is why you feel euphoric on a rainy day. I’ve been trying for years to find some sort of verification of this, to no avail. Standing next to a negative ion generator does nothing for me, so take it for what it’s worth. Maybe it’s a good thing you brought this up—somebody here may actually be able to shed some light on this.
Clue: when people who aren’t chemists, physicists, or metallurgists introduce ions as an explanation for anything the odds are good that it’s a complete nonsense claim. (I’m personally a little skeptical about metallurgists a good portion of the time, too, but that’s just personal prejudice.)
I don’t have any definitive answers for the o.p., but I’ve experienced the phenomenon as well. My speculation on the matter is that increased olfactory stimulus due to the rich cacophony of odors released by rain increases brain activity, which evokes memories and emotional responses and releases, naturally making you more alert and energetic. The pyriform cortex (one of the areas of the olfactory cortex where olfactory sensations are processed) connects directly to the hippocampus, the amygdala, the thalamus, and the hypothalamus, which collecitvely form the limbic system and control the memory recall, emotional response, spatial and temporal orientation, and sleep/alertness regulation. (Next to tactile sensation, smell is probably the most primative of the basic senses, and as such connects and influences “lower” brain functions extensively.) The resulting euphoria is most likely a result of being in a highly stimulating environment which evokes such basic responses. I’m not going to buy any explanations of “negative ions” or “environmental neurotransmitters” until otherwise backed up by some kind of actual science.
Stranger
I’ve experienced a similiar phenomenon after snow. But I suspect there is a physical reason for that.
Ok, the next time it rains, I’m going to bottle the air and sell it for $20 a bottle. Kind of like that scene is Spaceballs 
Isn’t ozone what you smell after a rain?
I think you’d be more likely to smell ozone after a lightning storm, or standing next to a busy photocopier.
OK, it appears that the person who told me about negative ions didn’t just pull a factoid out of his ass. At the very least, other people believe it too. Now to start sifting through the chaff for some reliable peer-reviewed verification of this notion. I’ll keep you posted…
Let’s hope you can find something more authoritative than
[ul][li]www.negativeiongenerators.com,[/li][li]www.ionlight.com,[/li][li]www.naturalhighs.net,[/li][li]www.negative-ion-generators.com,[/li]
[li]www.nutritionreview.org, and[/li][*]www.natural-salt-lamps.com[/ul]Stranger
Oh ye of little faith… 
Given the ease of generating negative ions, if they really did have a psychoactive effect surely we’d have proven it by now with lab experiments, right? I wonder if they’ve done double-blind tests to see if people report feeling better when exposed to a negative ion generator than when exposed to something that generates positive ions or none at all.
Here’s a Cecilian column on the topic:
Hm. I have been places where people had the things running. Something there made me feel bad. Made my head buzz. Given that I had read about the supposed benefits, you’d think I’d have been inclined, if I was going to feel a placebo effect, to feel good.
I have no explanation for it - all I know is I left in haste and remarked to my companion about how it made me feel. It was so wierd I never forgot it.