The use of new computer technology has improved the accuracy of next-day forecasts tremendously, and the forecasts up to three days are fairly accurate. For forecasts of more than five days, however, the number of calculations and the effect of uncertainties increase greatly. The low, middle, and high latitudes provide a basic framework for describing the earth's climates, which are defined in terms of yearly temperature averages. It is necessary to define the basic climates in terms of temperature because land and water surfaces react differently to incoming solar radiation, creating a different temperature. In general, the low latitudes receive a high amount of incoming solar radiation that varies little during a year.
Temperatures are high throughout the year, varying little from month to month.
The middle latitudes receive a higher amount of incoming radiation during one part of the year and a lower amount during the other part. Overall temperatures are cooler than in the low latitudes and have a wide seasonal variation. The high latitudes receive a maximum amount of radiation during one part of the year and none during another part. Overall temperatures are low, with the highest range of annual temperatures. The humid subtropical climate is one of short mild winters, humid summers, moderate precipitation.