Leftover air fried carrots can be stored in an airtight container in the fridge for up to 3 days. The butter will solidify a bit, but will soften up with no problem once you reheat them! To reheat, just pop them in the microwave for about 30-60 seconds. Alternatively, air fry them at 350 degrees Fahrenheit (177 degrees Celsius) for 2-3 minutes until heated through.