Much of Cumae's map is created by meteoric activity. Lake Turienne in Minon and Lake Marotes in Khafra, as well as Dihar island and the Gulf of Dihar were all likely formed by massive meteor strikes sometime in the prehistory of Cumae. In more recent recorded time, the elven nation of Lin was consumed some 18,000 years ago, leaving a plain of blackened glass a mile thick and eight hundred miles across in its wake.

The mountain ranges radiating from the dead land of Lin are mostly volcanic in origin, revealing the extreme stresses the impact placed on the surface. Massive lava flows flooded much of the land for hundreds of miles around the crater, and volcanoes in other nearby ranges also were likely set off by the sudden and intense increase in pressure. 

CLIMATE
The climate of Cumae is Mediterranean in the main, with the northern extremes much more severe in the northwest than the northeast, and the equatorial heat much stronger in the east than in the west, due to the shapes of the landmasses and the prevailing weather patterns.

As a result of the impact of the comet into what once was Lin, and the resulting volcanic activity that lasted for hundreds of years afterwards, the highlands of the Great Continent are now especially high, leaving the regions of Baelura and Skal under a near-permanent ice sheet. Dovaln, nestled between these and against the mountain wall of Lin, is more temperate both because of its lower elevations and because of the powerful magics the Dovalni can bring to bear to moderate the climate. Traediia is even more of a fertile lowland warmed significantly by airmasses rising off the desert and plains of Tiwwar. It is quite likely that before the lava flows added so much elevation to the northern plains, most of this region had a climate similar to that of Dovaln and Traediia today.

The southern portion of the Great Continent is quite warm and seasonal. In the southwest, the environment is quite arid and dry in the summers, though the land is fertile in winter and spring, and other times of year if enough water can be diverted to it from the rivers. Soame and Jungaeris are both dependent on seasonal rains and irrigation for most of their farm production, and the desert in central Soame is especially harsh, though not as lifeless as the deserts of Toz'Aizhir which remain year-round. 

The affects of rain, temperature and desert warming all work together to make Minon and Khazig both extremely fertile areas of the continent. By contrast the temperatures in Omeriat are quite good, but the land is almost entirely swamps or cracking sandstone hills not good for farming, mining or even quarrying, and its neighbor Scriegos is mostly highlands as well, though the combined influence of the gulf of Dihar and the Cumaean Ocean on this rocky promontory keep it between 55 and 80 degrees Fahrenheit year-round. Dihar likewise is always temperate, though in the winter it sometimes feels the chill of cooler air masses dropping from Baraeon.

The Arabian peninsula is quite cold in the north and northwest, but hotter than anyplace else on the Orbis further south. The hinterlands of Amossa are shrouded in icy peaks, tundra fields and frosty mist, but the southern protrusion dividing the Gulf of Amossa from the Arabian Gulf is quite warm and humid, and one of the most crowded living spaces in the world. Barzaal and Zuehed are likewise warmer but Barzaal is mostly rocky lands, a mystical place inhabited by more fighting monks than anyplace else in Cumae but not suited for farming, and Zuehed is a very swampy lowland that is flooded on almost a monthly basis, causing a great loss of life on occasion.

Dirzeh is blessed with good, fertile land, an excellent climate, and plenty of fresh water, and is well-insulated by mountains from the lands to the north and east. It is able to provide a great deal of surplus grain and other food to hot, dry Toz'Aizhir as a result. Toz is essentially a desert wasteland except for the edges of the wide, muddy river flowing through it; all of the land's cities are either on the river or the seacoast. Afternoon temperatures in the summer can often reach almost 125 degrees Fahrenheit, enough to cause heat stroke and death to the average human in less than two hours.

The Southern Continent is never dry, in any place, almost at any  time.  Khafra, likely the first part of the world colonized by any civilized humans, is blessed with soil so fertile that it can be used straight from the ground  to start cuttings from rare plants; but with rain more than 70% of the time, one needs to bring those cuttings in or they will rot in the water. Pilaan to the east is even more wet, overall, though this is split between a continually soggy southland and a drier but still tropical north. The eastern coast of this area contains vast shallow sandy beaches which some learned men claim are the remnant of a vast desert, and indeed some Pilaani myths speak of a time when drought was the rule and the land dried up and died. But for the last several thousand years, at least, Pilaan has been a deep rainforest. Most rainy of all, of course, is the Caetica, an untamed jungle wildland. It does have dry periods lasting up to three days, but rainfall rates in jungle villages have been measured at over four inches per hour. 

CURRENTS
The prevailing currents on the oceans are circular in a clockwise motion. The Triad Sea is a perfect example of this, with smaller currents in the inner gulfs turning counter-clockwise, driven by the force of the larger current. This creates some marked turbulence, however, where the Triad Sea meets the Khafran basin of the Cumaean Ocean. The waters of the basin are also traveling in a clockwise motion, driven by the warm water in the southern portion acting on the cooler water in the northern portion. Likewise the boundary between this basin and the main body of the Cumaean Ocean can be turbulent, though the temperature differences are not so great at that point since both are tropical to sub-tropical climates. The Vast Sea, on the other side of the Septesian Straits, can be especially dangerous in the spring and fall when the prevailing current is so strong that it can easily pull small oar-powered or single-masted craft out to sea, should they wander into the currents. As a result mostly of this current, there are few large port cities east of Naugor, and the lands of Pantanh are especially isolated as the current prevents ships from traveling from there south to Pilaan or to points west through the Septesian Straits. Travel to Pantanh is thus essentially one-way without magical assistance for returning, or a long trek over the steepest mountains on the Orbis. On the other hand, the Standing Sea is even more dangerous because of the icebergs and hidden currents coming off the blocks of ice floating through it in the summer. In the winter, of course, the sea freezes over from Baelura to Skal, with only a large lake of cold but melted water north of Dovaln, and icy slush north of Traediia. Parts of this sea never melt, and at the northernmost reaches of Baelura the ocean is frozen to a at least half a mile year round.

VIOLENT WEATHER
The great warmth of the Cumaean Ocean generates violent tropical storms and hurricanes during the late summer and early fall months. These storms have scoured entire cities off the Midaloth Islands, and batter Khafra and the coast of the Great Continent  from Jungaeris to Scriegos each year. On occasion these storms make their way into the Triad Sea where they wreak havoc on the less protected inner coasts. Rarely  tropical storms from the vast sea's southern provenance will make landfall on Pilaan's east coast, but these move against the prevailing currents and generally are not of great destructive power.

The Plains of Tiwwar are a hotbed of tornadoes from early spring until late fall, with the extreme storms coming at the beginning and end of this cycle when cold fronts with great variance from existing warm weather cells generate incredible thunderstorms and tornadoes. The mountain ranges which define the borders of Tiwwar tend to cut the bellies from these storms before they reach other regions, but tornadoes are occasional hazards in Khazig, Minon, and Dregagt. Sand cyclones are common in all the desert regions, where all that's required is heat and a slight crosswind to create a combination of updraft and spin that results in a tornado of sand. While much smaller and more localized in effect and duration, these storms can be deadly because of the tons of sharp sand particles whipping through the air. And in Toz'Aizhir's killer deserts, with incredible updraft speeds generated by the high heat, these sand twisters can combine on rare and deadly occasions into superstorms sandblasting everything in their wide path for miles. The wetter, greener strips of land along the banks of the Aphi river transecting Toz are insulated somewhat from these storms, but on rare occasions entire villages can be buffeted by these windstorms, where livestock left outdoors are sure to sicken and die from infection after having their skin scraped by the sand, and crops are left leafless and blasted into the river.