not much different from summer-time except for the 'extreme' days or nights.
In the summer, such as today, my main-use detectors are on the back seat of my vehicle. I cover them with a light-weight white, hospital-type blanket to keep the sun and average heat from them, and also block them from easy view. If a day is going to be blistering hot, such as close to or over 100° and I am not going to be detecting, then if I can't park in a shaded area, I bring my detectors in for the night. That's because I like to always be prepared for any detecting opportunity I can enjoy.
In the winter, such as will arrive in 2½ months or more, my main-use detectors are on the back seat of my vehicle. I cover them with a light-weight white blanket to keep them blocked them from easy view. If a day, or especially night, is going to be unbearably cold, such as close to or under 35° and I am not going to be detecting, and since I don't have a warm, protected garage to park in, I bring my detectors in for the day or night. That's because I like to always be prepared for any detecting opportunity I can enjoy.
If it is too hot or too cold for me to get out and swing a detector and have fun, or too hot or too cold to the point I might be concerned about my detectors' health, then I bring them in, but I don't store them away. I keep my main two or three detectors with me all the time because I am always on the look for any new opportunity when I travel, away from town or around the block. Otherwise, when I bring them in for over-night or a day or two, I just lean them against the way near my patio door [size=small](the door I use the most)[/size] with any extra detectors I have. I like jld66's simple plan where the detector is not underfoot but is also not out-of-mind or out-of-sight. It's there and quick-to-grab. :thumbup
Just because winter sets it doesn't mean I totally give up on detecting. I still hunt places like sledding hills, and, depending upon the amount of snow your area gets and the frequency of smaller plow piles melting, I hunt parking lots, especially at big shopping malls, etc. A lot of keys get pulled from pockets, often by gloved hands, and a lot of gloves are removed from pockets, or some remove gloves before getting into their vehicle. Change, keys, small pocket knives and all sorts of desirables get lost in parking lots. Many of those places get plowed and that can leave snow piles around the lot.
Snow piles can last for quite a while, depending upon the abundance of snowfall or severity of coldness, but they can also melt a little from sunlight warming, a passing rain shower, and some heating of the asphalt. A lot might depend on where you live [size=small](population)[/size] and the wintry weather duration, or even a person's health and desire to get out and deal with the cold. Today I live in North Central Oregon. The town is small with only 590-625 population, and while we had some cold weather temperatures last winter, it was usually cold but sunny. We only had four days of snow and that came about mid-February, and after those four days it melted off in just a few more.
While I have lived in Oregon for about ±55 years, it's usually been on the Western Oregon side and most winters we don't see much if any, white stuff. Sometimes it would get pretty cold and turn icy, freezing all the wetness from rain, which Western Oregon gets in the winter, but when the rain stops, you can still get out detecting. Soggy, but detectable weather as long as you're loaded-up and ready to put in a little hunt time.
When I have lived in Utah, and was younger and more 'durable,' I was in very populated areas with a lot of shopping locations that had big parking lots that got plowed often. Snow piles were everywhere! I added a simple hand-held hoe pick, as used for gardening or by gold nugget hunters, to chip away in the snow piles. I usually hunted very early, very late, often after dark, or on any occasion when many shopping sites were closed.
It could keep me active, find some good stuff other than just maintaining some degree of 'coin count,' and had me ready for the slide into spring-like weather when I could hunt playgrounds, lawns, get out to old sites [size=small](which I prefer)[/size] and also be ready to 'hit-the-slopes' as the ski resorts shut down for the season. Ski slopes, rope tows, under ski lifts, and especially working around the outer edges of the parking lot where snow plows and snow blowers clean off the parking and threw /piled all the good stuff. Coins, keys, cell phones, pocket knives, gold and other jewelry, and usually you chance upon paper money that was dropped loosely or in a money-clip, or even spot it in brush where the winds had blown it.
No, I always keep at least one detector, and usually my main three or four favorites, in my vehicle, or ready-to-grab when I head out the door, if it has been way too hot [size=small](summer)[/size] or too cold [size=small](such as some approaching winter weather might be for some)[/size]. I never, in all the decades I have been enjoying this great sport, taken them apart and boxed them up or stuffed them on a shelf or in the back of a closet. Instead, they are with me or indoors and close-at-hand where I can take a few minutes to 'Bench Test' them, compare some performance between two or more detectors, and always try to learn something new. To keep freshened on some of the subtle little strengths and weaknesses of detectors I own.
Guess it also might depend upon just how enthused we are about the metal detecting hobby and our willingness to learn more, or put them to use and find stuff regardless of the season.
Monte