Weather is defined as the condition of the atmosphere at a specific time, often for a specific place. As such, it is directly observable making it much less abstract than climate – more about this in Activity C. In observing weather, we break it down into elements that are discrete characteristics which vary over time and that are readily measurable (e.g. temperature or cloud cover).
Climate on the other hand, is a statistical portrait of the weather for specific places, regions, or even the entire planet. This information is meant to provide us a sense of what’s normal, what’s unusual, and what’s changing and how. To determine climate for a single station we use days, months, or years of data from that station to calculate averages and extremes of each of the elements observed at that station. To determine the climate of a region, we calculate these same statistics using data from several of the stations in the region. To calculate these statistics for the entire planet we use data from as many stations around the planet as is possible, as well as data from satellites and other mobile data collection platforms.
A weather report is like snapshot. By comparison, a climate record is a broad, long view of the data. The climate record enables us to see trends over the “noise” of the short-term fluctuations of our local, daily weather. The following activities are designed to illustrate this point by having you look at how the weather on two selected days reported from a single station compares to the climate statistics for that location.