Overview of IESREOnline Climate Normal Applications

      Climate normals are collections of variables that, over time, define climate. Typically, 30-year periods are used to define normals. For many variables, the "normal" is the average over those 30 years of some quantity, such as the temperature during a particular month or an entire year. Other values, such as standard deviations and degree days (which are accumulated values based on temperature) are also included in the climate normal datasets.       IESRE has provided three online applications for extracting climate normals for four different periods. The 1971-2000 and 1981-2010 datasets are in the same format and are accessed through the same application. The 1961-1990 and 1951-1980 datasets are significantly different from each other and the later datasets, so there is a separate application for each of those periods. THe 1951-80 and 1961-90 data are taken from a NOAA CD of climate datasets. The 1971-2000 and 1981-2010 data are based on NOAA data, but are taken from online datasets provided by a commercial weather service. Following U.S. weather reporting standards, temperatures are given in degrees Fahrenheit and precipitation in inches. More information about each dataset is available on the web page for the relevant application.
      The screen output from each application is in the form of comma-delimited fields. Select the output (Alt-A on Windows computers), copy it ((Alt-C), paste it into a text file ((Alt-V) using Windows' Notepad, for example, and save the file with a .csv extension. Then the file can be opened directly in a spreadsheet such as Excel. Why don't the applications create their own output files? Because the server on which IESRE's website resides does not allow the PHP programming language, in which the file-access portions of the application are written, to create output files on the website server. Considering how easy it is to cut-and-paste the screen output, this is not a significant problem.
      Each of the datasets is accessed by state. It should be noted that there is no reason to expect the set of stations in a particular state to be the same in the four datasets and, in fact, they are not. This can be seen in the longitude-latitude data outputs where the number and location of sites is different for each 30-year dataset.
      More information about NOAA's climate normal datasets is available at this NOAA website.