Climate and Weather
What’s the difference between climate and weather? Climate refers to the long-term weather patterns in a particular place, while weather refers to conditions at a particular time. We often say, “What is the weather right now?” or “What will the weather be like tomorrow?” On the other hand, if a friend is moving to another part of the country, we might ask, “What is the climate like there?”
Climate is not just the average temperature, precipitation, wind speed and direction, humidity, and so forth, but the ranges and types and seasonality of all those things. For example, Seattle and Washington, D.C. have similar annual precipitation totals, but quite different climates. The Seattle-Tacoma Airport receives an average of 37.4 inches (95.0 cm) of rain per year, and the Washington National Airport in D.C. receives an average of 39.7 inches (101 cm). But Seattle has 150 days with rain a year, while D.C. has only 107. Seattle is often drizzly in fall, winter, and spring, and dry in the summer, whereas D.C. can be snowy or icy in the winter and has frequent thunderstorms in the summer, as well as the occasional tornado or hurricane.1
Over time, plant and animal species have adapted, through natural selection, to the specific climate where they live. A plant species that thrives in the climate of the Amazon basin would not be able to survive in the Sonoran desert.
Local climate varies of course. One winter will be colder than usual, one summer will be wetter than usual. It can vary on larger scales as well—one decade can be colder, warmer, wetter, or dryer than usual. And there may be severe events—such as hurricanes or droughts or floods—that happen only once every several years or only once every generation or only once every century. Individual plants and animals may die during these types of variations or severe weather events, but natural communities as a whole survive and thrive in the climate where they are located.
For example, if a storm knocks over several mature trees in a forest, tree seedlings on the forest floor will take advantage of the sunlit opening to grow and become part of the canopy. Natural communities can recover from even very large storms if they are surrounded by natural areas that can serve as a source for new plants (seeds) and animals to populate the damaged area.
If, however, a natural community is small or isolated—perhaps surrounded by urban and suburban development—then severe natural disturbances such as hurricanes or widespread ice storms pose a greater threat.
Another more serious threat to natural communities around the world is global climate change.