"Many of you ask us if it has to be hot to roast and if we can only roast in summer. In reality the answer is no, because only the solar radiation matters for heating power. For example, even though there is snow all around us, we heat the oven just as much as in the middle of summer. Just as it is possible to get sunburned in the mountains in winter. On the other hand, if the sky is cloudy or something gets between the sun and the earth, like the smoke from Canadian fires in July, then the heating power is reduced and we will take 45 minutes instead of half an hour to rise to 180°C."