The climate at D:FR is roughly classified as mid-elevation desert. It is neither as hot as nearby locales to the south and west, nor as cold as the higher elevation mountain and plateau country to the east. The Sunset Western Garden Book Climate Zones Map shows this to be a borderline transition zone between zones 11 and 12, as defined in the text of that publication. Zone 11 is mostly high-elevation Mojave Desert of southeastern California and southern Nevada, and Zone 12 is mid-elevation Sonoran Desert found in southern and western Arizona. Most Americans will be more familiar with the United States Department of Agriculture winter hardiness zone map. In placing D:FR on the USDA map, the location is defined as zone 9B, or the colder half of zone 9. The USDA uses average minimum winter temperatures as the baseline for this classification system. Zone 9 has lows most winters in the 20 to 30 degree range.
Specific climate information is not available at D:FR for the long term, because of its remote location and lack of nearby weather stations. The following information is based on observations over the past three years, climate data extended to the site from nearby locales with a weather station, and inference from ecological patterns and plant distribution.
High & Low Temperatures
Average high in July: 102° F (38° C)
Average low in July: 75° F ( 24° C)
Average high in January: 62° F (17° C)
Average low in January: 34° F (1° C)
Possible summer highs: up to 110° F (43° C)
Possible winter lows: down to 22° F (-6° C)
Extreme summer highs: up to 117° F (47° C)*
E
xtreme winter lows: down to 15° F (-10° C)*
*Note: these are extremes, unlikely to occur more than once a decade or so, if even that often
RAINFALL
The rainfall at D:FR averages about 8 to 10 inches (20 to 25 cm) per annum. The exact amount is unclear since no long-term weather records exist. This extrapolation is based upon existing weather records for the surrounding towns of Kingman, Yucca, and Wikieup, Arizona, as well as an interpretation of the rainfall required to support the native vegetation on and around D:FR. Rainfall is bimodal, meaning it tends to occur in two distinct seasons every year. There is a winter rainy season, usually in the months of January, February, and March, and a summer monsoon season in July, August, and September. Rainfall tends to be approximately evenly distributed between the two seasons. Rain is possible any month of the year, but is very unlikely to occur in May or June, and not very likely in October and November.
Winter rains tend to be frontal in nature, with wet storm systems moving in from the Pacific Ocean over California and into the interior deserts of the Southwest. The nature of these storms is that they are generally cool and gentle, producing slow rains that last for hours or days, thereby giving the soil moisture levels a chance to recharge. Plant growth is sometimes inhibited by the cool temperatures, but the low evaporative rates preserve the soil moisture levels until springtime warmth arrives so that the plants may better utilize the available water. There are, however, many plants that grow only during the cooler months, and go dormant during the summer heat and drought. Rainfall in the late fall and early winter is responsible for the spectacular spring wildflower displays often featured in the travel magazines and tourist literature of the Southwest.