- Standard values for a location
- Data averaged on a monthly basis of at least 30 years
- Daily data including temperature and the amounts of rainfall
Limitations of normals
- Normals offer valuable information, they must be used with caution
- Normals are not intended to describe usual weather conditions; they average over a long period of time.
Causes of Climate
- Differences in latitude, topography, closeness of lakes and oceans, availability of moisture, global wind patterns, ocean currents, and air masses are different causes of climate.