The one thing about Canterlot that really got to Rarity was the rain. Not that the rain itself was terribly onerous—it actually rained less there than it did in most of the surrounding areas, since it took less rain to water the small parks and gardens than it did to keep farmland healthy. But the nature of the rain was so... inorganic. Without exception, every Tuesday and Thursday the weatherponies would begin gathering clouds in the early evening and there would be a light drizzle that lasted from seven thirty on into the night.

Rarity gets caught in the rain and catches a case of homesickness.