During the outbreak of the phylloxera plague in the 19th century, Jumilla surprisingly escaped contamination and so entered a period of economic expansion as wine merchants from France came in great numbers to buy wine. For this reason the vines were never re-grafted onto resistant rootstock from the New World, as was the case in the rest of Europe. It is a transition zone, characterized by wide valleys and high plateaus, between the Mediterranean coastal area and the high central plateau of Castile-La Mancha; the altitude of the vineyards varies between 1,300 and 2,600 feet. The area is arid; rainfall is low (around 10 inches) and irregular, though it mostly falls during spring and autumn, often in the form of violent storms, which can sometimes cause damage to the vines. The average annual temperature is 60°F though a maximum of 105°F can be reached in summer and minimums below 32°F in winter. There is a risk of frost up to the month of March, exceptionally until April. The vines receive over 3,000 hours of sunlight per year. The soils are permeable and have good moisture retaining properties, which allow the vines to survive during periods of prolonged drought. They are quite sandy, allowing good aeration, have a high pH value and are low in salinity.