Now that winter is officially finished, we can look back at the temperature data and compare reality to what we remembered. I think everyone here in Central Illinois perceived our latest winter to be warmer than the one before it, but prolonged cold (and warm) spells have a way of making comparisons difficult from year to year. The data is presented again this year in the form of combined bar and line charts. The blue bars represent the deviation of the daily mean temperature from the historical average where each bar represents one day. The red curve represents the cumulative deviation from the historical average, and indicates whether the season as a whole was colder or warmer than what we'd typically expect.
It's also interesting to note that the winter as a whole was warmer than normal until the last week of February, indicated by the red curve crossing the x-axis into negative territory on February 26. February 27 added momentum to that move by recording the largest deviation from average of 28 degrees F below the historical mean. The deviation of 23 degrees F above normal on March 23 recorded the largest deviation on the warm side.
winter of 2013-2014 and notice that the cumulative temperature that winter was above normal only a few days all season. I think most of us are happy not to repeat those temperatures this year.
Since our historical mean temperatures are still low enough to expect heating degree days this time of year, we are technically still in our heating season. We'll continue to compile data to see whether this heating season as a whole was warmer or colder than average.