Screaming rain
Screaming rain is a strange meteorological phenomenon unique to the veigur of Ufmarkt. Even the undead who make up most of the population of the veigur take place when the screaming rain comes, because it damages not just the body but the soul, and even the undead are susceptible to it. Fortunately, the screaming rain is a relatively rare phenomenon, though there's nowhere on Ufmarkt that seems entirely safe from it.
Many scholars believe that the screaming rain is a remnant of whatever disaster made Ufmarkt what it is today—that the "raindrops" are made of real soulstuff, the mutilated remains of unfortunates who for whatever reason didn't make the transition into full undeath. This is unproven, however, and there are other theories about the screaming rain's origin—though they're at least as speculative.
Appearance
Screaming rain gets its name not from any sound it makes—the rain is in fact nearly silent, accompanied by only a faint crackling noise—but from its appearance. The rain takes the form of bright aqua-colored smears of glowing substance each of which seems from some angles to bear a screaming face, with indigo blotches seeming to form two eyes and a gaping mouth.
The individual "drops" of screaming rain vary in size from a few centimeters across to about two decimeters. Generally, the rain is not so dense as to seriously impede visibility, with perhaps three to twelve "drops" per square meter per second. Curiously, within a given screaming rainstorm, all the "faces" are oriented in roughly the same direction, at least locally.
Occurrence
A given area on Ufmarkt tends to experience the screaming rain, on average, perhaps once a year. There's no obvious pattern to the storm's occurrence, however, and it may come twice or even more times in quick succession and then not visit the area again for years. Despite careful measurement, scholars have found no evidence of screaming rain occurring in any areas significantly more than any others, except that it does seem to occur somewhat less often near the veigur's border.
When the screaming rain does come, the storm may last anywhere from about two hours to, in extreme cases, as many as twelve. A storm of screaming rain generally covers an area of several hundred square kilometers, though occasionally much larger storms do occur, their areas an order of magnitude larger. The storm itself doesn't seem to move; the rain simply starts and then dwindles and stops while confined to the same region.
While screaming rain doesn't seem to emanate from ordinary clouds, and so one cannot look to cumuli to cast their coming, still there are signs of their imminence that can warn the observant. A few hours before the onset of screaming rain, the sky begins to take on a subtle but notable blue tinge, and the sharp-eared may hear a very quiet, intermittent buzzing in the air.
Effects
The substance that makes up the screaming rain is not anything resembling water. It seems to be some kind of modifed soulstuff, and has deleterious effects on living—or undead—beings. Contact with most unliving materials has no particular result, the rain simply spattering off the surface and quickly evanescing into nothingness. In contact with living tissue, however, it is highly dangerous, seemingly attacking not the flesh it touches but the soul of the body that flesh pertains to. Those who are exposed to the screaming rain feel as if it burns their souls where it hits, and feel pained and weakened. But the effect is more than just sensational, as, while doing no direct harm to flesh, it apparently eats away at the souls within. The effect is most noticeable in ghosts and other incorporate undead, but it is no less dangerous to embodied creatures, even if the damage is less directly visible. Too long exposure to the screaming rain can kill, in a way that prevents (or at least drastically complicates) exsuscitation; the victim's soul is dissolved away, perhaps to become a part of the next screaming storm.
Because of the dire effects of the screaming rain, inhabitants of Ufmarkt know to take shelter as soon as the rain appears. Fortunately, it doesn't take much to shield a creature from the rain; a simple overhang or even a sheet of canvas will do; the rain is capable of soaking through thin cloth, but is stopped by anything thicker. Nor does it puddle on the ground for long; it dissipates shortly after contact with a solid surface. For that matter, the same applies to a liquid surface, and since it doesn't sink in most liquids, diving underwater—or underlava—provides sufficient protection as well. Thus, the only individuals in severe danger from the screaming rain would be those traveling across a flat land with nothing to cover themselves. For precisely this reason, anyone seeking such a journey will generally bring with them a roll of material that can keep off the screaming rain. The chances of being caught in the rain may be low, but the consequences are terrible enough to justify the proverbial ounce of prevention.
There are those who have somehow inured themselves to the screaming rain, and not only are not harmed by it (at least not fatally), but somehow gain powers from it. This process is often called drinking the rain, and those who practice it raindrinkers. It may be worth noting that what little flora exists on Ufmarkt seems to have developed the ability of raindrinking, of necessity to survive the infrequent but imperillous screaming rains. This means that Ufmarkt's sparse vegetation, too, makes for safe shelter in a screaming rainstorm—but it also means that many of the veigur's flora exhibit unusual abilities just after such a storm.
Resources
Wothe as the rain may be, raindrinkers are not the only ones to find some benefit from it. While it normally fades away not long after coming to rest, enchantments have been developed that allow the rain's substance to accumulate in specially prepared containers called rainbowls. So gathered, the substance of the rain forms a bright blue liquid that has come to be known as cerulean tears (a bit misnomeredly, as "cerulean" generally describes a somewhat different shade from the rain's electric blue). Valuable as an alchemical reagent and for other magical uses, and perhaps possessing potential uses still undiscovered, cerulean tears fetch a high price in parts of Ufmarkt, and a still higher price elsewhere, being sometimes exported to distant vegari.