Temperature figures are given in degrees Fahrenheit. Giving an average temperature for most national parks is not an easy thing, as huge variations in elevation lead to huge variations in temperature. The classic example is Death Valley National Park. With an elevation range of over 11,000 feet, temperatures cover an enormous range. While it may be 125°F at the lowest spots, it may be 60°F or even lower on the mountain peaks. If the site of measurement is known, we will state it. Otherwise, use temperatures as relative guides only.

Precipitation (Pcpt) is measured in inches. It is important to note that precipitation is amount of water - in many parks some or all of the precipitation in some months may be snow, which does not convert easily to water amounts. Heavy snow may only have a 6:1 ratio, whereas light snow has been known to be 20:1 or even greater. Use it only as a relative guide in the parks that receive snow. To further complicate matters, many mountain parks have a "dry side" and a "wet side", while others are large enough to have several different weather patterns within them.