Heart of the Hill Vineyard is located in the heart of Red Mountain, the smallest appellation in Washington State at 4,040 acres (1,630 ha planted). The area has a desert climate with average yearly rainfall of five inches per year. During the growing season, daytime temperatures average 90 °F (32 °C) with nighttime temperatures dropping below 50 °F (10 °C). Varieties from Southern France (like Mourvèdre) or Italy thrive in these hot and desert-like conditions.