CI imatological records for existing stations in and near the 

 study area are published each month by the National Weather Service (18) . 

 Short and long-period weather forecasts for the area are regularly furnished 

 by offices of the National Weather Service in New York City, N.Y., Windsor 

 Locks, Conn, and Bridgeport, Conn. 



As part of the Long Island Sound Regional Study, the cl imatolog- 

 ical data for the period 1951-1970 together with selected long-period infor- 

 mation was inventoried and analyzed by the National Weather Service. Most 

 data was obtained from the archives of the National Climatic Center, Ashe- 

 ville. North Carolina. The existing records are of good quality and areal 

 distribution, except for the area directly over Long Island Sound, Records 

 from all stations in New England and parts of eastern New York were used to 

 evaluate monthly and water year precipitation, whereas the balance of the 

 cl imatological analyses are based on data from 15 stations supplemented 

 where necessary by additional stations. The locations of the principal and 

 supplementary stations are shown in Appendix D. 



Approximately 100 tables, graphs and maps prepared for the Long 

 Island Sound Regional Study are listed in Appendix C of this report. They 

 depict averages, extremes, ranges and variability in time and space of 

 climatic events or contain statistics on frequency, variability and probabil- 

 ity. Because of the scope of available information only brief descriptions 

 of specific climatic phenomena are contained in this report. Therefore, in 

 the sections that follow the objective is to apprise the report user of what 

 information is available on specific topics such as temperature and precipi- 

 tation. 



3.3 Temperature 



The mean annual temperatures generally decrease eastward from 

 New York City, inland from the Connecticut shoreline and from the interior 

 toward the shore on Long Island. Mean annual temperatures for the region 

 range from kS to 55°F, are lowest in eastern Connecticut, northern portions 

 of southwestern Connecticut and in eastern Long Island and are highest in 

 western and central Long Island. Maps showing the geographic distribution 

 of mean annual temperature and mean annual temperature range are listed in 

 Appendix C. Mean annual temperature has little significance in an area where 

 daily ranges vary from 10 to 25°F and annual ranges vary from ]k to 23°F. 



Monthly mean-maximum, mean-minimum and mean temperatures have 

 been tabulated for the region (see Appendix C) and provide a basis for pre- 

 dicting future temperatures. Monthly mean-maximum, mean-minimum and mean 

 temperatures all trend in a latitudinal direction except where topography 

 and the influence of the Sound predominate. The moderating influence of 

 Long island Sound is best defined in late spring and summer when water tem- 

 peratures are cooler than air temperatures and in late autumn and winter when 

 water temperatures are generally warmer than air temperatures. 



A water year is the continuous 12-month period, October 1 through 

 September 30. It is designated by the calendar year in which it ends. 



. 8 



