I’m happy to report that the seeds I started inside a couple weekends ago have started germinating. Hooray!
All seeds have an optimum temperature at which they germinate best, but also a range of temperatures in which they will germinate. Here are the optimal temperatures for some common fruits and vegetables. When I started the seeds it was still over 100 degrees outside; not much will germinate in that type of heat. (Turnips, apparently, are an exception as their range goes up to 105. Several turnip seeds that I direct seeded outside have started to come up.) In the basement where I started the seeds the temperature was around 78-82F, so this is within the optimal range for most of the things I planted (and, if nothing else, was a lot better than the 100+ temps they would have seen outside).
Once I saw that a few of the seeds had sprouted, I turned on the lights that I have specifically for starting seeds. The lights are suspended from the basement rafters by chains, so I can move the lights up and down as the plants grow. Provided everything goes well with these guys, we should be in good eats this fall and winter.