50°F - 75°F
This is the temperature range where a couple more layers can be added for the lower end of the spectrum. You won’t need anything too insulating, and based off your activity level, an insulation piece may not be necessary. Mid-layers are a great addition here, they have more insulating properties than your base, and will be cut to fit over your next-to-skin layer. In this range you will most likely be putting on and taking off layers as the weather and activity levels change.