The perfect temperature to roast most vegetables is 400 degrees Fahrenheit. This helps the veggies taste lightly crisp and caramelized on the outside and tender on the inside. The oven brings out the vegetable’s natural sweetness. Of course, oven cooking temperature will vary on type and size of vegetable, but 400 degrees Fahrenheit usually does the trick! I have found that most root vegetables roast perfectly at this temperature.