1919] METEOROLOGY. 809 



pressure, temperature, humidity, precipitation, wind, sunshiue, cloudiness, and 

 casual phenomena during September and October, 1919, are presented. The 

 data are briefly discussed in general notes on the weather of each month. 



Climatic factors [at the Hettinger substation, N. Dak.], A. J. Ogaaed 

 (North Dakota Sta. Bui. 130 U'JIO), pp. 31-35, figs. 5).— Rainfall data for Het- 

 tinger from 1910 to 1917, inclusive, and for New England, about 40 miles 

 northwest, and Orange, 30 miles southeast of Hettinger, from 1894 to 1909, in- 

 clusive, are summarized in tables and diagrams. Data are also given for 

 evaporation, temperature, frost-free period, and wind velocity at Hettinger, 

 1911-1917. 



The average annual rainfall for the region was 14.03 in., the average for 

 Hettinger being 14.37 in. The avei'age seasonal rainfall was 10.84 in. The 

 average seasonal evaporation (April to September) was 32.78 in. The average 

 frost-free period at Hettinger was 112 days, varying from 91 days in 1911 to 

 128 days in 1912. May 15 is considered a comparatively safe date for planting 

 coi-n, in most yeiirs. The data recorded do not indicate any progressive 

 climatic changes in the region. 



The weather of the past agricultural year, F. .J. Bkodie (Jour. Roy. Agr. Soc. ' 

 England, 79 (191S), pp. llJt-18Jf). — The weatlier conditions, particularly rain- 

 fall, temperature, and sunshine in Great Britain during the winter of 1917-18 

 and the j^ear 1918 are briefly summarized as in previous reports. 



Swedish meteorological observations (Met. lakttag. Si^erige (Observ. M6t. 

 Sii^d.), Met. Centralanst., 57 (1915), pp. XIII+181; 58 (1916), pp. A'/F-f-iSi).— 

 These are the detailed tabular reports of the Central Meteorological Institute 

 of Sweden for 1915 and 1916. 



Warm season droughts (U. S. Dept. Agr., Nat. Weather and Crop Bui., No. 



19 (1919), pp. 2, 3, figs. 2). — Two charts are given which sliow the percentage 

 of years with 30 consecutive days or more without 0.25 in. of rainJall in 24 

 hours from March to September, inclusive, and the longest period in 20 years 

 when similar conditions prevailed. 



Drought periods of the character indicated " occur with less frequency in the 

 interior of the Northeast, in tlie area extending northward from the central 

 Appalachian Mountain districts through Ohio, and in the Southeast. In these 

 sections there is experienced, on the average, only about one year in three 

 having a period of one month's duration without 0.25 in. of rainfall in 24 

 hours. The percentages increase, as a rule, to the westward, and in the more 

 western portions of the Great Plains phenomena of this character are prac- 

 tically of yearly occurrence. In the Ohio, central Mississippi, and lower Mis- 

 souri Valleys the percentages range from 40 to 50, but are somewhat higher 

 to the southward, while they show a rapid increase from the eastern portions 

 of the Plains States towai'd the western portions." The number of consecu- 

 tive days without 0.25 in. of rainfall from March 1 to September 30 during a 

 period of 20 years ranges from a maximum of about 80 in the western Great 

 Plains to a minimum of about 40 from the central Appalachian Mouptains 

 northward to Lake Erie. 



Average summer rainfall ( U. S. Dept. Agr., Nat. Weather and Crop Buh, No. 



20 (1919), pp. 2. 3, figs. 2). — Charts are given which show for the various sec- 

 tions of the country the average amount of rainfall for the three summer 

 months. June to August, inclusive, and the percentage of the annual precipita- 

 tion that occurs during the summer months. A wide difference in summer rain- 

 fall in different parts of the country is shown, the minimum being in the 

 southern Pacific coast districts and the maximum along the west coast of the 

 Florida Peninsula. 



