National Weather Service United States Department of Commerce

This page will try and guide you through accessing data via NOWData web page.  

The tabs below have examples.

Monthly and Daily Normals/Averages

Follow these step to get the monthly or daily normals for a location.

The graphic below show the steps.

  1. Select the location either from the list or map under "1. Location".
  2. Under the "2. Product" select Daily/Monthly Normals.
  3. Click on either the Monthly or Daily button under "3 Options".  More data is display when using the Daily selection.
  4. Then choose the Variable from the pull down menu. The menu has the following selections,
    • Temperatures
    • Precipitation
    • Temperature/Precipitation
    • Snowfall
    • HDD base 65 (HDD = Heating Degree Days, see bottom of page)
    • CDD base 65 (CDD = Cooling Degree Days, see bottom of page)
    • GDD base 65 (GDD = Growing Degree Days, see bottom of page)
  5. Click on the Go button under "4. View".

Steps to get normals.

The resulting display contains both a graph and a table. The graph is interactive.  Moving the mouse pointer over the graph will show values on both the monthly and daily selections. Clicking on the Enlarge results will produce another browser window with the graph and table.  However the graph is NOT interactive, but one can scroll down through the table of data.

 

Example of pop out window containing monthly data graph and table.

 

References:

  • Degree Days - A measure that gauges the amount of heating or cooling needed for a building using 65 degrees as a baseline. Electrical, natural gas, power, and heating, and air conditioning industries utilize heating and cooling degree information to calculate their needs.
  • Cooling Degree Days - (Abbrev. CDD) - A form of Degree Day used to estimate energy requirements for air conditioning or refrigeration. Typically, cooling degree days are calculated as how much warmer the mean temperature at a location is than 65 °F on a given day. For example, if a location experiences a mean temperature of 75 F on a certain day, there were 10 CDD (Cooling Degree Days) that day because 75 - 65 = 10.
  • Heating Degree Days - (Abbrev. HDD) - A form of degree day used to estimate energy requirements for heating. Typically, heating degree days are calculated as how much colder the mean temperature at a location is than 65 F on a given day. For example, if a location experiences a mean temperature of 55 F on a certain day, there were 10 HDD (Heating Degree Days) that day because 65 - 55 = 10.
  • Growing Degree Days - (Abbrev. GDD) - A corn growing degree day (GDD) is an index used to express crop maturity. The index is computed by subtracting a base temperature of 50 F from the average of the maximum and minimum temperatures for the day. Minimum temperatures less than 50 F are set to 50, and maximum temperatures greater than 86 F are set to 86. These substitutions indicate that no appreciable growth is detected with temperatures lower than 50 or greater than 86.

More on degree days can be found at the CPC website.