8 Climate Basics
Learn how weather differs from climate, what shapes regional climate patterns and zones, and how natural variability differs from lasting climate change.
and
describes atmospheric conditions at a particular place and time, such as the day's temperature, wind, clouds, or precipitation. These conditions can change within minutes or from one day to the next.
describes long-term patterns in a region. It includes typical temperatures and precipitation, seasonal cycles, and the range of conditions that occur. Scientists often use averages over 30-year periods to describe . However, an average alone does not capture : the amount of variation and the frequency of extreme conditions matter too.
A single cold day does not by itself show that a place has a cold . records help show how that day compares with usual regional conditions and with the full range of conditions observed over many years. In short, is what happens on a given day; describes what is typical and how much can vary.
Patterns and Zones
patterns differ across Earth because the Sun heats the planet unevenly. Latitude is a major influence: places near the equator receive more direct sunlight through the year, while high-latitude regions receive less direct sunlight and have greater seasonal changes. Elevation, nearby oceans, mountains, and large-scale atmospheric circulation also shape regional temperature and precipitation patterns.
group regions with broadly similar long-term temperature and precipitation patterns. A common classification identifies five types:
Tropical
Dry
Temperate
Continental
Polar
Some classifications also describe highland climates, which are shaped by elevation. Each category may have subtypes. For example, dry climates may be deserts or steppes, and temperate climates may have wet or dry seasons.
-zone boundaries are not sharp lines. Conditions often change gradually across a landscape, and nearby mountains or coastlines can create distinct local climates.
and Change
means fluctuations in conditions around a longer-term pattern. It can occur across seasons, from year to year, or over longer periods. A region may experience a wetter-than-usual season or an unusually cool year without its long-term necessarily changing.
One source of year-to-year variability is , a natural pattern involving the tropical Pacific Ocean and atmosphere that can shift rainfall and temperature patterns in many regions.
Variability and change are related but distinct. Variability describes ups and downs around a pattern; change is a lasting shift in the pattern itself. To identify a long-term shift, scientists examine many years of observations rather than drawing conclusions from a single storm, season, or unusually hot or cold day.
Key Takeaways
describes short-term atmospheric conditions, while describes long-term regional patterns and their range of variability. organize broad patterns of temperature and precipitation, but local geography creates variation within zones. naturally varies across different timescales, and a temporary fluctuation is not, by itself, evidence of a lasting shift.