In this Applet you can examine maximum and minimum temperatures as well as precipitation as a function of date and month over the period 1948 to 1998 (and later as more recent data become available).

You can plot data as a line plot or as a histogram. You may over-plot different data sets and different colors will be auto-chosen.

Follow the examples below to get you started. Note that once the data file gets read once it will reside in you computer's memory for relatively fast access.

Example 1: Comparing max temperatures for a specific month in different years.

• Select maxtemp.txt as the data file
• Select March as the month
• Select 1990 in the year box (the upper one with only one line)
• Hit Graph (it will take a while for the data to download the first time)
• Now select 1994 and hit graph again.

You get the idea, we hope. hitting clear, clears all graphs.

Example 2: Plotting max temperature and rainfall for a specific month:

• Hit clear if there are graphs present
• Select March 1994
• Hit Graph
• Now select precip.txt and hit graph. Both plots should be on the same page. Note you can perform cursor interrogation on any plot by positioning the cursor where you want and hitting the left-mouse button. The X and Y positions will be read out and printed where it says X=0 and Y=0 on the left hand side.

Example 3: Time Series for a particular date.

• Hit clear if there are graphs present
• Select maxtemp.txt as the input file
• Use the bigger year box near the bottom and select 1948 as the starting year by highlighting it. Now scroll down the box and select, say 1995, as the ending year by highlighting it.
• Now pick a date using the Month and day dialog boxes (which is located right above the X= and Y= fields). If you are following this example you should still be in the month of March. now select say, March 30, by going to the day box and selecting 30.
• Now go to the top dialogue box (the one under the Clear button) and select date vs data
• Hit Graph and voila.
• Now select histogram as the plotting option in the top dialogue box. Hit the clear button. Then hit graph. Notice that the distribution of max temperature is not very Gaussian on this particular date!

These examples should get you started.