Death Valley Weather

Hottest Daily Average Temp is 116 (July) and lowest 38.3 (December

Dangerously hot during the day from June through September with average monthly highs during that time ranging from 109 to 116.5.  Cycling is not recommended during the summer and certainly never without good SAG support.  The heat can be stifling (if not truly dangerous) and supplies are few and far between.  

According to Wikipedia weather summary:  

"The hottest air temperature ever recorded in Death Valley was 134 °F (57 °C) on July 10, 1913, at Furnace Creek, which is the hottest atmospheric temperature ever recorded on earth. During the heat wave that peaked with that record, five consecutive days reached 129 °F (54 °C) or above. Some meteorologists dispute the accuracy of the 1913 temperature measurement.

The greatest number of consecutive days with a maximum temperature of 100 °F (38 °C) or above was 154 days in the summer of 2001. The summer of 1996 had 40 days over 120 °F (49 °C), and 105 days over 110 °F (43 °C). The summer of 1917 had 52 days where the temperature reached 120 °F (49 °C) or above with 43 of them consecutive. Four major mountain ranges lie between Death Valley and the ocean, each one adding to an increasingly drier rain shadow effect, and in 1929, 1953 and 1989 no rain was recorded for the whole year.[9] The period from 1931 to 1934 was the driest stretch on record with only 0.64 inches (16 mm) of rain over a 40-month period. On June 30, 2013, during the 2013 extreme heat wave, the mercury reached 129 °F (54 °C) at Furnace Creek station, which is the all-time hottest air temperature recorded for the month of June.

The mean annual temperature for Death Valley (Furnace Creek Weather Station) is 77.2 °F (25.1 °C) with an average high in January of around 67 °F (19 °C) and 116 °F (47 °C) in July.[11] From 1934-1961 the weather station at Cow Creek recorded a mean annual temperature of 77.2 °F (25.1 °C).

The longest number of consecutive days where temperatures reached 90 °F (32 °C) or more was 205 from April to Oct 1992. On average there are 192 days per year in Death Valley where temperatures reach 90 °F (32 °C) or more. Before being moved to Furnace Creek, the weather station at Greenland Ranch averaged 194.4 days annually where temperatures reached 90 °F (32 °C) or more.

On July 12, 2012, the day's low temperature was 107 °F (42 °C), tying the record for the world's hottest low temperature ever recorded. On the same day, the average temperature was 117.5 °F (47.5 °C), which is the world's hottest temperature averaged over 24 hours on record.

The lowest temperature recorded at Greenland Ranch was 15 °F (−9 °C) in January 1913.

On April 22, 2012, Death Valley recorded the hottest April temperature in North America: 113 °F (45 °C), beating the previous record by over 2 °F.

The period from July 17 to 19, 1959, was the longest string of consecutive days where nighttime low temperatures did not drop below 100 °F (38 °C)] On July 12, 2012, the low temperature at Death Valley dropped to just 107 °F (42 °C) after a high of 128 °F (53 °C) on the previous day. Death Valley's overnight low of 107 °F (42 °C) ties the record for the world's warmest low temperature ever recorded (Khasab Airport in Oman also recorded a low of 107 °F (42 °C) on June 27, 2012). Also on July 12, 2012 the mean 24-hour temperature recorded at Death Valley was 117.5 °F (47.5 °C), which makes it the world's warmest 24-hour temperature on record.

The average annual precipitation in Death Valley is 2.36 inches (60 mm), while the Greenland Ranch station averaged 1.58 in (40 mm). The wettest month on record is January 1995 when 2.59 inches (66 mm) fell on Death Valley. The wettest period on record was mid-2004 to mid-2005, in which nearly 6 inches (150 mm) of rain fell in total, leading to ephemeral lakes in the valley and the region and tremendous wildflower blooms. Snow with accumulation has only been recorded in January 1922, while scattered flakes have been recorded on other occasions."