Adiabatic

Meaning: not involving the transfer of heat, or im-pass-able to heat. An adiabatic process is one in which no heat is exchanged. It's related to the First Law of Thermodynamics and consequently various other sciencey things, including weather. 

Logofascination: 2. I'm still on a science-word kick. If I have made any sense of what I've read*, the weather part kicks in where you have changes in temperature caused by changes in atmospheric pressure, as opposed to changes in temperature because heat has been added or removed (e.g. by a desert wind or an Antarctic wind, both of which you will get in an average Melbourne day).  Etymologically, it's from the Greek for "not to be passed through".

In the wild: Reading up on names of winds; wind-words are one of my special logofascinatorial sub-categories. The adiabatic process is influential in both a Foehn wind and a Katabatic wind.

Usefulness: 5, unless you can wangle it convincingly into a conversation with a scientist, or meteorologist. I am tempted to stretch it to my bedroom: an adiabatic chamber, impassable to heat.



*amateur translation here; let me know if it's not quite right. 

Simoom

Meaning: a hot, dry African wind - one of the winds whose names are lovelier than the reality (not that I've experienced one... yet).

Usefulness: 3 (I've known this word for a long time, but I think this is the first time I've used it.)

Logofascination: 1 (There's something about the names of winds: they have their own Wikipedia article, and there are slightly different lists all over the internet. Growing up, I took the Fremantle Doctor for granted, not realising how lucky I was to know a wind with a name, let alone a pleasant one*. The simoon** is, etymologically, poison.)

In the wild:  Yes; I discovered it as the name of a submarine, a Polish espionage movie, and in various bits of Bible commentary.