318 EXPERIMENT STATION RECORD. [Vol.43 



METEOROLOGY. 



Report of the chief of the Weather Bureau, 1919 ([7. S. Dept. Agr., 

 Weather Bur. Rpt. 1919, pp. 296, pis. 7).— The work of the Weather Bureau 

 during the year ended June 30, 1919, and the general weather conditions of 

 each month of 1918, as well as the outstanding meteorological features of the 

 year, are reviewed, and detailed tabular monthly and annual summaries of 

 climatological data for 1918 are given as usual. 



Recognizing that " weather is a dominant factor in the success or failure of 

 agricultural or horticultural operations . . . special effort was made during 

 the year to apply the information collected, through the vast oi'ganization 

 of special and cooperative services of the Weather Bureau, to the important 

 problem of food production in its various aspects." Special features of the 

 report from the standpoint of agriculture are charts showing departure from 

 normal temperature, total and departure from normal precipitation, and occur- 

 rence and distribution of injurious hailstorms during the crop season (March 1 to 

 September 20, 1918). 



" The most remarkable feature of the weather of 1918 was the prolonged period 

 of marked cold over the central and eastern parts of the country, which, having 

 set in during December, 1917, continued till about February 6, then ended 

 abruptly. No other 2-month period averaging so cold appears in the tem- 

 perature statistics of the central valleys, the Ohio drainage basin, the central 

 South, or the Atlantic States. ... In the middle and southern Plains there 

 was rather severe heat for over two months, about June 10 to August 20, 

 which aided the shortage of rainfall to produce serious harm to crops and 

 pasturage. Ample and well-distributed moisture, with mainly mild weather, 

 during the last few months of the year in districts where late crops and fall- 

 sown grains are very important was decidedly favorable and showed a great 

 contrast with the conditions in 1917." 



Meteorological summaries (Kentucky Sta. Rpt. 1918, pt. 1, pp. 69-71). — 

 Tables compiled from the records of the U. S. Weather Bureau Station at 

 Lexington, Ky., summarize data for temperature, precipitation, humidity, wind, 

 and cloudiness, 1872-1918. 



Climatic conditions [on the Yuma Reclamation Project, 1918], R. E. 

 Blaik (U. 8. Dept. Agr., Dept. Circ. 15 (1920), pp. iO-i J). —Observations on 

 precipitation, evaporation, wind movement, temperature, and killing frosts, 1910 

 to 1918, inclusive, at the Yuma Experiment Farm, are summarized and dis- 

 cussed. 



The average temperature of 1918 was 69.35° F., as compared with a 9-year 

 mean of 69.15°. The maximum temperature was 115°, the minimum 19°. The 

 total precipitation was 3.57 in., as compared with a 9-year average of 4.11 in. 

 The evaporation was 73.02 in., as compared with an averge of 78.33 in. The 

 f restless period was 261 days, from February 19 to November 7. The weather 

 conditions of the year were generally favorable for all crops except cotton. 

 This was injured by very sudden and extremely high temperatures in Augiist, 

 and by a freeze that occurred November 6. 



Comparing observations at the experiment farm, which is representative of 

 valley lands of the project, with records made at the Yuma office of the U. S. 

 Weather Bureau, which are more nearly representative of conditions on the 

 higher lands, it appears that "during the four months of ordinary frost — 

 November, December, January, and February — the minimum temperatures at 

 Yuma are generally fronr 5 to 8° higher than in the valley, while tlie maximum 

 temperatures average about 1° less. Throughout the remaining eight months of 



