[WHERE?] Hogwarts grounds initially, but believe me, it will move indoors.
[WHY?] Because Hestia seizes any chance there is to get out of the rain.
Hestia had never liked rain, sleet or snow.
Narcissa loved it, of course. "Dramatic," she called it. "Beautiful." Then she'd go on talking about how she hoped there would be a light snowfall at her winter wedding, or how it meant luck for a marriage if it rained during the wedding ceremony - Hestia couldn't really bring herself to tell her friend that she didn't give a shit (not that she would use those words, of course! So crude!) so Cissa kept on talking.
Hestia, on the other hand, despised it: rainy and snowy weather meant cold weather. She would sniffle, her cheeks tinge with pink, her black hair unfurl from its carefully bepotionedand set waves. Not the best of looks, and it seemed dangerously close at hand: it was pissing down, right now, as she was strolling the grounds on Prefect's duty.
Only three more minutes, now.
Nothing was happening - not that she'd like it to; she suspected that noticing any illicit activities would encrouch on her free time even more than ordinary Prefect duties already did - still, Hestia was quite bored.
Two more minutes then I can go inside.
Passing the gamekeeper's hut, Hestia spotted a familiar figure - and those two last minutes be damned, she thought, as she strode up to him and grabbed him by the tie.
"Tybalt, we're going back to the castle. Now."