According to Hoenn's most ancient legend, the rainy season belongs to Kyogre, the dry season to Groudon, and those brief periods of nice weather in between should be attributed to Rayquaza, who takes over during the transition to stop the two from fighting.
The rice farmers of the lowlands, for whom a long rainy season meant a larger harvest, prayed to Kyogre; the pastoralists of the highlands, who raised ground and fire pokemon that struggled to tolerate storms, including the notoriously drought-immune Camerupt, understandably prayed to Groudon instead.
Such are the origins of the two teams, Aqua and Magma, who have played such an immense role in the history of the region.
Management of the calendar was the primary task of the Emerald State of Hoenn from the beginning of its history. Its taxes, armies, diviners and priests all aimed at a goal virtually absent from contemporary statecraft, but one which dominated ancient thought: keeping Groudon and Kyogre away from one another long enough that the planting and the harvest could occur during the two brief Rayquaza intervals between the seasons.
Yet the Emerald State's authority, in ancient times, was rarely unchallenged; at its nadir, it ruled only what was visible from the Sky Pillar, its citadel, Rayquaza temple, and most famous surviving monument.
Bitter invectives against the "Sharpedo Barbarians" and "Camerupt Barbarians" dominate many texts from this period, terms which were almost certainly circumlocutions, given the minimal position of those pokemon in proto-Aqua and proto-Magma's own iconography. But Groudon and Kyogre, whose importance was acknowledged by everyone on the island of Hoenn, could hardly be demonized, and treating their enemies as worshipers of legitimate deities opened uncomfortable questions; might the people of the Lavaridge Volcano, given their dry climate, be justified in only acknowledging Groudon?
The Camerupt Barbarians were semi-nomadic raiders, and as such, polemics against them dominate the written sources from the period of the Emerald State. Yet as fellow agriculturalists, it was the Sharpedo Barbarians who represented their most serious ideological and political rival – had one war ended differently, it would be them, not the Emerald State, who would have ended up as this region's progenitors. Therefore, coinage and monuments (and, undoubtedly, many speeches and festivals, now lost, intended for public consumption) far more frequently emphasized the themes of Rayquaza subduing Kyogre, preventing floods and typhoons, and driving away the rain.
Such a civilization could not help but struggle with environmental disaster, especially one which disrupted the seasons themselves.
Historians still debate the causes of the so-called "year of Groudon", a year of extreme heat and severe drought which effected not only Hoenn, but most of the known world. Modern climate scientists typically attribute it to simultaneous eruptions of Volcanion and Heatran, but around the world various theorists have at times invoked Chi-Yu, Moltres, Entei, or even Solgaleo to explain the incident.
The monks who lived through the Emerald State's decline and fall, and give us our final literary source before the Hoenn Dark Age, however, had no doubts about what caused the Year of Groudon. Groudon had grown larger and stronger that year - "what was black was now gold, what was grey was now black, and all around the land was desolate," they wrote, "and not even Rayquaza and Kyogre, together with all the men and pokemon of two armies, could bring it down.".
They were baffled at why it happened – had the high priest really not set out tasty enough Minior candies at the Planting Festival, and if so, would it even have mattered? And one must admit that there is a troubling discrepancy between their account of a blazing, intense sun, and those from elsewhere of one blotted out by dust.
Sadly, for all the fascination which the Rayquaza Crash has held for centuries, all the way down to the present day, it remains difficult to answer that particular question. What we can say for certain is that a civilization founded on managing the two seasons could not survive a single failure.