Tutorial: Accessing Historical weather data through the United States Historical Climatology Network (USHCN)

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1 1 Tutorial: Accessing Historical weather data through the United States Historical Climatology Network (USHCN) The United States Historical Climatology Network (USHCN) is a high-quality data set of daily and monthly records of basic meteorological variables from 1218 observing stations across the 48 contiguous United States. Daily data include observations of maximum and minimum temperature, precipitation amount, snowfall amount, and snow depth; monthly data consist of monthly-averaged maximum, minimum, and mean temperature and total monthly precipitation. To access data from the USHCN: 1. Follow this link to the USHCN Homepage: 2. Click Data Access 3. Click the Web Interface for a graphical approach to accessing the data:

2 2 4. Select a state from the pull-down menu on the right labeled Select a state: 5. Click MAP SITES. Pushpins will appear on the map at weather station locations. Tools on the left of the map allow the user to zoomed in or out or pan to the proper location. Click on the weather station site of interest. The options for getting data ( get monthly data ) are hyperlinks directly to the next set of data choices. 6. Using daily data is best for professional level calculations, however, the amount of data available requires a significant amount of time to process many calculations for learning purposes are based on monthly data.

3 3 7. From the selections you will see (below), select the specific data you wish to plot (for example mean temperature ) or download U.S. Historical Climatology Network - Monthly Data You have chosen site , CANTON 4 SE, New York Available Plots: Number of months with data vs Year Mean temperature vs year Precipitation totals Climate variable vs month Climate variable box and whisker plot Available download files: Create a download file of monthly data Create a download file of data summarized by year (Jan 1 - Dec 31) Create a download file of data summarized by hydrological year (Oct 1 - Sep 30) The following screen will appear if you choose one of the download available data options:

4 4 Select the data you want by clicking in the boxes to the left of the description. You can edit the time range for data to cut down on the size of the file, however, data is not available previous to the date initially listed on the left or after the date initially listed on the right. Click the submit button to access a link to download the csv file. Click the link provided to download the.csv file.

5 5 Follow the directions in the Excel Tutorial for instructions on how to open the csv file in Excel.