Congrats on the buds. No idea if the rain helped . I would guess just a coincidence.

I lost a bunch of flowers the last time it rained. I think the rain just helps pull the loose petals off.

Rain could have washed the ferts to where the roots could use them or thinned them out so they weren't too strong if you were using too much.
Buds just might have been waiting for the plants to be able to support them...coincidence...
I think a mild rain soaks the soil better and it seems that a good soaking from rain aleays perks up plants better than a hose watering ever does.
Might be all that acid rain and smog pollution stuff getting washed into the soil.
Youre plants are high on pollutants right now and have the munchies. LOL

Lol. Just glad they actually had some good progress. I was getting a bit discouraged seeing so many blooms drop unfertilized. I think in a week or two, I will be seeing little pods everywhere. My only plants that are not producing a lot of blooms is the Charleston and the Banana Peppers. But, it seems like nearly every bloom puts out fruit.

By your description of the appearance of and the dropping of the petals, that is a normal progression of their fruiting. The blossoms dropping with stems is another matter, not normal and can have several causes.

1. Over or under watering.
2. Poor drainage. The roots do not like to be soggy for very long.
3. Too much fertilizer, especially Nitrogen.
4. Not enough Magnesium, needed when they are very young and when they start to blossom/fruit.
5. Weather conditions, if the plants think it will soon be winter, they will drop their less mature blossoms and/or fruit to give the more mature ones a better chance to propagate.

There are probably others I haven't learned yet, I only make a few mistakes at a time.

Happy planting,
Pic-Z

this is my first year growing anything outside, but I know the answer to this one, ocasionally depending on where u live rain water can have pollutants in it, but for the most part, Rain water is far superior to tap water, for starters the highly oxygenated water of rain is much better for the roots and the plant in general, than the chlorinated water that picks up whatever smegma may be in the pipes as well. but the oxygen which is at a premium for roots stimulates growth and fertility, kinda like a human in a hyperberic chamber.