Climatic data for the Continental United States for the 1850's and 1860's are compared with the currently valid normals. In the eastern half of the United States, these two decades continue the cooler and somewhat wetter character found in an earlier investigation, while in the western half, a distinctly warmer and decisively wetter climate existed in the mid-19th century, as compared to the conditions in the first half of the 20th century.

A comparison of climatic data for the eastern United States from the 1830's and 1840's with the currently valid climatic normals indicates a distinctly cooler and, in some areas, wetter climate in the first half of the last century. The recently appearing trend to cooler conditions noticed here and elsewhere could be indicative of a return to the climatic character of those earlier years.

No abstract

An investigation of temperature and additional records shows the existence of a pronounced January thaw in New England. This singularity can be connected to the existence of typical changes in the circulation over the United States. Further world-wide relations indicate important consequences valuable for further research on singularities.

A sudden increase in the probability of snow occurrence during the month of October at Denver, Colorado, had been reported. It is shown that this increase can be associated with the development of a widespread weather singularity occurring at that time of the year. The normal sea-level pressure-pattern changes derived from 40 years of data over the United States show the synoptic development of this singularity. This development leads to peculiarities in various weather elements at that time.