A PREDICTION OF WASHINGTON TEMPERA- 

 TURE 1948 (MADE JANUARY 1948) 



By C. G. abbot 



Research Associate, Smithsonian Institution 



ABSTRACT 



The author in January 1948 predicted 55 dates in 1948 as near dates of 

 minima in Washington temperatures. He predicted that between successive 

 pairs of these dates higher temperatures would occur. He predicted that the 

 average excess of these higher temperatures over those of the predicted dates 

 would be 7°. I F. On January 19, 1949, the Director of the Astrophysical Ob- 

 servatory checked the prediction and found that in 48 of the 55 cases higher 

 temperatures did intervene, and that their average excess was 6?96 F. The 

 author shows by a graph that the main part of the brief fluctuations in tempera- 

 ture ordinarily ascribed to "weather" is caused by a periodicity of 6.6456 days 

 in solar radiation, rather than by terrestrial complexities, as generally sup- 

 posed. The author claims that similar successful predictions may be made 

 for any station and, if desired, for many years in advance. The predicted dates 

 of minima are approximate, and may be out of phase by l, 2, or rarely 3 days. 

 If predictions are limited to i or 2 months in advance, however, displacements 

 of phase may be nearly eliminated. A prediction of approximate dates for 

 Washington minimum temperatures for 1949 is given. 



In January 1948 I made a prediction relating to temperatures at 

 Washington for the entire year 1948. I then sealed the prediction 

 and placed it in the safe in the Smithsonian accounting office, with 

 the provision that it was to be opened on or about January 20, 1949, 

 by the Director of the Smithsonian Astrophysical Observatory. 



This paper contains the text of my prediction for 1948, the veri- 

 fication of the prediction by the Director of the Astrophysical Ob- 

 servatory, comments on the outcome, and my prediction for 1949. 



PREDICTION FOR 1948 



In Smithsonian Miscellaneous Collections, vol. 107, No. 4, 1947, 

 I disclosed an average period of 6.6456 days in temperatures of 

 Washington and other cities, identical in length with a periodic vari- 

 ation of solar radiation. Due, as I suppose, to complex terrestrial 

 influences, the phases of this period shift somewhat as to tempera- 



SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. Ill, NO. 6 



