Weather factors have been shown to affect human behavior and mood. On the other hand, mood has a strong effect on total demand and demand for specific products. In this study, we have tested the effect of 17 different weather factors on the demand for specific restaurant menu items. We have also tested the effect of weather factors on the demand for different menu item categories, on hot and cold, and light, medium, and heavy menu items. The results indicate that different weather factors have different effects on different menu items and that the sales of some items are more affected by weather while others are not affected. These results can be used in the process of menu engineering and for the differential pricing of menu items according to the changes in weather factors.