Do you have any thermometers specifically for your garden endeavors? A soil thermometer to judge whether seeds or sensitive roots can go in? A green house thermometer? Cold/hot frame thermometer? Compost thermometer?
I just use a thermometer from the kitchen-- a dairy thermometer because it reads low enough for outdoor things.
The last I used a thermometer was for my recently picked winter squash curing under a poly tunnel. I really don't need one, but it is nice to have every now and then.
Actually, where I probably ought to use one is in spring when starting seeds in small plastic containers. Whoa, those poor seedlings' soil can get really hot, especially when in black plastic. If I kept a thermometer in with a plant or two, maybe I'd treat them a little better....I remember doing an experiment in a biology lab where we measured the water uptake of a plant over just a few minutes and I was so impressed that I got a lot better at not letting plants go dry. If I were to measure the temp of the soil in the little punnets and pots, maybe I'd be shaken awake and get them into bigger pots or into real soil sooner.