Climate vs. Weather

I apologize for today’s short post. Today is the Stony Brook University Intramural Softball championship game, and I have to leave the office early to hold down 3rd base. Tomorrow we’ll pick back up with “serious” environmental dialogue and address the insight that this blogs only reader, Mikey P brought to the table.

Weather versus Climate
The most difficult lecture for me to give to the students in my Environmental Problems and Solutions class at Stony Brook Southampton is the lecture on Global Climate. Specifically, trying to explain to the students what the major difference is between weather and climate. Here then are the definitions of climate and weather respectively from the American Heritage Dictionary.

cli•mate n.

1. The meteorological conditions, including temperature, precipitation, and wind, that characteristically prevail in a particular region.
2. A region of the earth having particular meteorological conditions: lives in a cold climate.
3. A prevailing condition or set of attitudes in human affairs: a climate of unrest.

Climate implies a long term series of conditions, the average of which we consider to be the “climate of a region.” It’s also important to consider the expected variability associated with a region, for example in April one could expect a day with a high of 30 or a day with a high of 70, both of which are within normal bounds, neither of which alone truly describe the climate of April.

weath•er n.

1. The state of the atmosphere at a given time and place, with respect to variables such as temperature, moisture, wind velocity, and barometric pressure.
2.
1. Adverse or destructive atmospheric conditions, such as high winds or heavy rain: encountered weather five miles out to sea.
2. The unpleasant or destructive effects of such atmospheric conditions: protected the house from the weather.
3. weathers Changes of fortune: had known him in many weathers.

Weather, the definition implies atmospheric conditions at one time. The weather can vary greatly from one day to the next, whereas the climate should vary only slightly from day to day or even week to week for a region.

Anyway I bring this up because today is a good example of why we need to include a degree of variability when ascribing climate to any region. The weather map below, taken from http://www-frd.fsl.noaa.gov/mesonet/ shows the wide range of temperatures in the Northeastern US today.



Today temperatures range from a very autumnal upper 50’s in the Adirondacks, Green, and White Mountains, to the 60’s across most of Western New York and the Catskills, to the 70’s throughout most of southern New England and the Hudson Valley to more a more “seasonable” lower 80’s in New York City and Long Island. However just to the south in New Jersey and Pennsylvania temperatures are in the 90’s with high humidity – the epitome of an August day along the Eastern US coastline. And of course far to the south Tropical Storm Fay continues to subsume Florida with rain and wind.

Any way, the point of all of this is just to say that when we define climate we need to be careful to include variability in our description. Today’s cool temperatures are part of a “normal” climate for the Northeast – although one may consider this to be somewhat extreme weather. This is a good example that one could use to explain the difference between climate and weather.