The temperatures where Quasi & I are are frequently over 30C in Summer.
I'm pretty sure Quasi has cured evaporation from his containers, I know that I lose little if any ether to evaporation.
I keep my ether in 2 litre glass Winchesters, with perfect screw caps. The Winchesters are then kept in a metal locker in the coolest part of my shed. I've never noticed an ether smell on opening the locker, which would indicate leakage.
When you are getting your ether from your pharmacy, ask if they have any suitable glass bottles. Ensure that the caps are fume resistant and all should be well.
Certainly true. Right now in my shed there are four 2.5 Litre Amber Winchester bottles full of Ether. This is about a years supply for myself and a few others. Despite the high summer temperatures (up to 44 degrees C one day recently) there is never any loss, or any Ether smell. Like Greg I keep them on the cool Southern side of the shed in a safe place and regularly replace the screw on caps with new ones when they're refilled. Both Winchesters and new caps are available at a local Industrial bottle wholesaler.