The climate of a particular region (or planet) is based on the variation in the average weather over a long period of time, typically more than 30 years.
The variables that are measured are:
- atmospheric pressure
- atmospheric particle count
- and other meteorological variables.
When we talk about the weather it covers the same variables but describes the variation over shorter periods of time.
When the term climate change is used it refers to a significant change in the normal weather patterns over a long period of time.
This results in more extreme weather events such as storms and droughts.
More information on climate change can be found at the EPA site.