Autumn is a great time of year to begin helping children understand the temperature. It's an active time weather-wise, so they'll see lots of swings from hot to cold in many regions. Apply temperatures to the practical act of choosing a wardrobe with a thermometer like this one from LucasWorks:
The dial face of the Apparel Indicating Weather Thermometer displays coats, jackets, pants, and shorts for the different temperatures of the seasons. A quick check of the outdoor temperature comes alongside an appropriate wardrobe choice for the day, which can help children understand the relationship between outdoor temperatures and what they're wearing. Understanding the reasoning behind their wardrobe might help little ones get on board with adjusting from the shorts-and-tees uniform of summer to pants and jackets for autumn.
As a bonus, the thermometers from LucasWorks support a great cause: they are made by people with autisum. Their work helps them to understand temperatures too, as well as assembly skills, word processing, and packaging technicques!
Even if the LucasWorks thermometer is not for you, however, you can still teach your children the importance of dressing weather-appropriately by afixing your own clothing icons to an outdoor thermometer!
Find it: Apparel Indicating Weather Thermometer at LucasWorks, $17