Logically Consistent Weather on a Mars-inspired World

[Inchoroi]

So, my group and I have gotten together, and decided on the type of genres we want to play in, which, it turns out, is sort of like the setting of the anime Trigun, plus magic rather than technology. I had the idea last night to place the game on a world inspired by Mars. This made me wonder: how does the weather on Mars work?

From doing research, here's what I've come up with so far. I want to make sure that it's logically consistent so far, before I try to add in more details.

* Aphelion = Summer

* Perihelion = Winter

* 668 days in a year; 25 hour days (in reality, 24h 39m 35s).

* Aphelion (summer in the northern hemisphere), and is the temperate season, which lasts a significant amount of the year, longer than winter lasts in the northern hemisphere.

* Perihelion (winter) in the northern hemisphere isn't a true 'winter', but it is the dry season, with large dust storms, making travel very difficult. Further north, however, snow falls, which then evaporates and drops as rain during Aphelion, only to evaporate and fall as snow again during Perihelion.

* Aphelion in the southern hemisphere is the season of dust storms; they rage throughout the entire season, scouring the southern hemisphere. The dust storms trap the sun's heat, raising the temperature and making it warmer.

* Perihelion in the southern hemisphere, however, is an even dryer time, with no rainfall at all. The dryest time of the year in the southern hemisphere only lasts a small part of the year, but once it's over, it gets very cold which lasts a long time, during the wet season of Aphelion in the nothern hemisphere.

* The Valles Marineris always fogs over before sunrise, the fog and frost burning off early in the morning, just after sunrise.

* The weather between the northern and southern hemispheres are very different.

N. Hemisphere S. Hemisphere
* Summer; 183 days; Winter
* Autumn; 147 days; Spring
* Winter; 158 days; Summer
* Spring; 199 days; Autumn

* The sky changes color depending on how much dust is in the sky; sometimes it is pink and cloudless, filled with microscopic dust, which are often the warmest days. Others, the dust is swept from the atmostphere, and clouds form against a dark blue sky. It during Aphelion that the wet season starts in the northern hemisphere, with the dark thunderclouds, cooler weather, and the dark blue skies. During Perihelion, however, the sky is often pink and cloudless, with dust storms across the planet.

[MysticMonkey]

Seems to be pretty consistant. If you have not, might I suggest reading Red Planet by Robert Heinlien. He includes a bit about weather on Mars and migration from north to south (and visa versa) by human colonists because of the drastic weather changes. Also having a lot of permenant settlement near the equator.

If you are going to base your planet off Mars, it stands to reason you would run into some of the same issues.

That is old, classic sci-fi so it might not be your cup of tea.