In 1891 an observer of the U. S. Weather Bureau remained in Death Valley from May to September, during which time he made daily observations of the weather. His experience was a most trying one, drawing heavily upon his physical and mental stamina to complete the period of time that had been set for him. For the entire time of one hundred and fifty-four days less than one half an inch of rain fell. There occurred several days in succession with a temperature of 122°. However, this is not the highest temperature ever recorded in the United States. In July, 1887, at Mammoth Tank, in the Colorado Desert, the temperature reached 128° in the shade, and again, in 1884, 124° was reached at the same place. On July 18, 1891, in Death Valley, the maximum was 120° and the minimum 99°, making an average for all hours of 108.6°. The extremely high temperatures reached in the Colorado Desert, which embraces a portion of Southern California and Arizona, do not vary greatly from those of Death Valley; they are not exceeded anywhere in Central or North America. Such degrees of heat, if experienced for two or three weeks in the more humid regions of the eastern half of the United States, would nearly depopulate the region by the havoc of death. The lowest temperatures in the United States occur in extreme northern portions of Minnesota, North Dakota, and Montana, where temperatures from 50° to 55° below zero have been recorded. It is interesting to note that in this same region the summer temperatures have risen to readings of from 105° to 108°. Of course this heat is quite different in its effects upon life from the heat of the Gulf or Atlantic coasts. One feels a marked difference between the sun and the shade temperatures in these semi-arid regions. Sunstroke is infrequent and death seldom results from exposure, as it does in the East. The region of severest cold in North America is found about the Great Bear Lake in the British Northwest Territory, where temperatures of 58° below zero have been recorded. =South America.= The hottest portion of South America is in the interior, with extensive systems of mountain ranges along the coast preventing the inward flow of the moist rain-bearing winds from the ocean. In a stretch of country extending from Uruguay northward into the interior of Brazil, the average of the highest temperature of each year for a period of several years is 104°, with individual readings much higher. Except on the top of the mountains, or well up their sides, no severely cold weather occurs in South America, seven eighths of its territory lying between the equator and latitude 30° south.