The Rainfall Festival is the shortest-running holiday on the island. It celebrates the arrival of the rainy season, where crops are plentiful and the water levels rise and unite the bodies together. Non-aqualoxes grumble about the "flooding", though, as this primarily aqualox-observed holiday launches into full swing.
This holiday is all about the unity of different people and cultures. It's an especially important holiday during times of high tension. The most notable occurrences are the parades that march from one side of the island to the other, gathering more members and merging with other parades as they pass through town after town. Flooding the parade-route roads are all sorts of carnivals and fairs that serve as a rest-stop for the parade's participants. Here, Safirans can eat free food and spend some of their cash on fair rides and games. Some come home as lucky winners, while others may find their wallets lighter than before.
The parades serve Safirans in several ways. Many aqualoxes, no longer fearful of their manes drying out, take it as an opportunity to adventure! Other Safirans use the rising tides as an opportunity to visit family and share their stories. Some hope to be lucky enough to meet one of the High Priests or Summoner Marsh's Royalty. Meanwhile, the less aquatically inclined find themselves skittering in and out of their homes, snagging candy and toys from passing Fools, then dashing back inside to dry off their rain-soaked selves.
These parades are comprised of several different members, but the most well-known are the Fools. These Safirans join in the parade with all sorts of goodies that they pass out to townsfolk as they dance across the island. From candy to expensive jewels, the Fool could hand out anything, but a few Fools are secretly Court Jesters. You'll know if the gift you received is from Court Jester by a sigil carved into the object. This sigil changes every year, to prevent cheaters from forging Court Jester objects.
Why someone would forge a Court Jester's gift? The answer is simple: they wish to receive the prize associated with the sigil. Those who have a sigil object are given a choice: they can either keep their object with its sigil mark or exchange it for a wish. These wishes are extremely valuable and can do any number of things, although there are limitations. Wish restrictions include anything that would harm an individual or the community (such as wealth that could ruin the economy, or death upon another), anything that would change the social structure of a region (such as wishing yourself to be a High Priest), and... well, the list goes on.
But the Rainfall Festival is not limited to the parades. Some dedicated Poco tamers spend their time on a great search for a rare type of poco: the Founding poco. Founding poco are coveted by all Safirans, but aqualoxes in particular. It's not uncommon for a stray poco to be scooped up immediately upon sight, although the likelihood of one meandering into town is zero to none. Strangely enough, your best bet is to simply find a quiet vista, where the rain is currently falling, and wait for one to appear before you. What causes these poco to appear, no one knows for sure, although some hypothesize that it's the good cheer and strong rains that summon the tiny creatures further into the mortal-dimensions.