Information for Yachtsmen
Panama - Pacific International Exposition San Francisco 1915

GENERAL INFORMATION FOR YACHTSMEN The coldest month was January, 1890, when the mean tempera- ture was 7.8° C. (46° F.), and the warmest month, September, 1889, when the mean was 18.3° C. (65° F.). In an average year there are approximately 1,311 hours when the temperature is above 15.6° C. (60° F.) ; 4,111 hours when the temperature is above 12.8° C. (55° F.) ; and 7,625 hours, or about 87 per cent of the entire year, when the temperature exceeds 10° C. (50° F.). ( Differences between day and night temperatures are small. The warmest hour, 2 p. m., has a mean temperature of 15.1° C. (59.2° F.). The coolest hour, 6 a. m., has a mean temperature of 10.5° C. (50.9° F.). The highest temperature ever recorded in San Francisco is 38.3° C. (101° F.). This occurred September 8, 1904, during a pro- longed period of warm weather. For 4 consecutive days maximum temperatures exceeded 32.2° C. (90° F.). This was the warmest spell of which there is record in San Francisco. In the past 20 years there have been 27 days on which the temperature exceeded 32.2° C. (90° F.); but with the exception noted above there has been no period of 3 consecutive days when this temperature has been ex- ceeded. The lowest temperature recorded since 1871 is —1.7° C. (29° F.), which occurred January 15, 1888. In the last 20 years the tempera- ture has not fallen below 0° C. (32° F.). The following tables gives the monthly and annual extremes of temperature, from 1871 to 1911, inclusive: Maximum Lowest Maximum Minimum Highest Minimum January.... February.... March...... April...... May........ June....... July....... August..... September . October.... November... December... All years °C. °F. 26 78 27 83 27 80 31 88 36 97 38 100 37 98 33 92 38 101 34 94 28 83 22 72 38 101 14 58 16 60 17 62 17 63 21 70 19 67 19 66 20 69 20 69 22 18 64 15 59 °C. —1 7 6 .6 2 0 6 0 8 0 8 0 8 0 8 0 7 0 3 0 10 °F. 29 33 33 36 4? 46 47 4S 47 45 38 34 8 46 8 47 10 50 9 49 10 50 12 53 12 54 12 54 12 53 12 53 10 50 7 44 14 58 —1.7 29 12 54 The absolute range of temperature from 1871 to 1911 is 40° C. or 72° F. MONTHLY RAINFALL—APRIL The mean rainfall is 1.64 inches. The month of heaviest rainfall was in 1880, when 10.06 inches was measured. There have been 6 Aprils out of the past 63 in which the rainfall equaled or ex- ceeded 5 inches. There have been 27 in which the amount of rain did not exceed 1 inch. No rain fell in April, 1857, and there was only a trace of rain during April, 1909. The largest number of con- secutive rainy days occurred in 1880, when it rained for 11 days. The average number of rainy days in April is 6. The greatest 24-hour rainfall was 2.43 inches on April 24, 1896. 6