late 14c., "horizontal zone of the earth," Scottish, from Old French climat "region, part of the earth," from Latin clima (genitive climatis) "region; slope of the Earth," from Greek klima "region, zone," literally "an inclination, slope," thus "slope of the Earth from equator to pole," from root of klinein "to slope, to lean" (see lean (v.)).
The angle of sun on the slope of the Earth's surface defined the zones assigned by early geographers. Early references in English, however, are in astrology works, as each of the seven (then) climates was held to be under the influence of one of the planets. Shift from "region" to "weather associated with a region" perhaps began in Middle English, certainly by c.1600.
The general or average weather conditions of a certain region, including temperature, rainfall, and wind. On Earth, climate is most affected by latitude, the tilt of the Earth's axis, the movements of the Earth's wind belts, the difference in temperatures of land and sea, and topography. Human activity, especially relating to actions relating to the depletion of the ozone layer, is also an important factor.
A region's usual weather patterns. The climate at any point on Earth is determined by things such as the general movement of the atmosphere, the proximity of the oceans, and the altitude of the location.
Note: The climate also is affected by the sun, by changes in the orbit of the Earth, by plate tectonics, and by human activities, particularly the burning of fossil fuels, which may lead to a greenhouse effect.