theres a lot of different varieties, but many onions can be grown through the winter and are often planted in early fall.
you can totally plant them up now, they do ok in cool and cold weather.
when it gets hot they tend to flower, so its good to start them early and get them big enough before that happens. cause then they put their energy into flowering and not growing bigger bulbs.
Montana has cold dark nights. Perfect for the heat from incandescent light. Tiny ad: