In Ohio, it seems like winter is finally ending. Later than many would like, but we nonetheless enjoy periodicity in this world; half a year from the height of winter (~180 days), we can expect warm weather; and vice versa.
But in the world of Westeros,* that is just one more luxury they do not have. Winters come in uncertain lengths after uncertain times with uncertain ferocity. Is there some way to predict this, saving lives from starvation, to really know when Winter is Coming?
It could be possible, so long as we can determine what causes seasons on that world. For Earthlings, the tilt of the planet relative to its orbit about the Sun provides the seasons. But when it comes to Westeros, there are several opinions. However, they have their own problems. A variable tilt to the planet has the problem that the Moon will stabilize it; considering the Moon is regular enough to time the cycles of “flowering” ladies, there seems to be a fairly regular Westeros-Moon system. The elongated orbit would not do well to explain the irregularities of winters.
When I have thought about it, the simplest solution seemed to be a binary star system. We have actually detected planets in such systems, though most news outlets relate this to Tatooine, not realizing the potential to talk about other fictional worlds. However, my day dreams never became a paper, and now someone has “published” their results.
Using a model of two stars like our Sun, the planet of Westeros will have a variable distance from the solar system’s barycenter (center of mass) between 1.5 and 2.5 astronomical units. This solar system model provides the non-periodic lengths of summers and winters, and it also shows there can be wide differences between mild and severe seasons.
So, thank goodness there are dedicated grad students who are figuring out how to deal with the problems of fantasy worlds. Next, I hope to read about the geology of Casterly Rock and see where else there may be places to find gold untouched by corrupt Lanisters. We should also be getting a chemistry paper on dragon fire in the next month, and a ecological report about the self-connected biome of Weirwood and one Stark child. And this should be done seriously. This is no mummer’s farce.
* The planet itself is never given a name in the books, simply ever called “the world”.