How are weather and climate forecasts different? 


The old adage “climate is what you expect, weather is what you get” correctly expresses the main distinction between climate and weather. Climate is the average of weather conditions, such as temperature and precipitation, that are observed over extended time periods, such as a month, season, year or longer. This distinction is also reflected in forecasts.

Weather forecasts produced by NOAA’s National Weather Service provide a detailed description of expected weather conditions from several hours to several days into the future. For example, a forecast may read: Sunday in Washington, DC, will be mostly cloudy with a high of 86 degrees and West winds at 5 mph. These forecasts also include details about specific events, such as a winter storm or a severe thunderstorm.

Climate forecasts, issued by NOAA's Climate Prediction Center, are predictions further into the future (weeks, month, and seasons) where the daily details become more uncertain. To address this uncertainty, NOAA provides forecasts expressed in probabilities or chances. For example: There is a 40 percent chance of warmer-than-normal temperatures in July across the eastern half of the U.S.

Many sectors of the economy – including energy, agriculture, aviation, water resource management communities, private industry, and academia – rely heavily on the use of climate and weather data and forecasts to make informed economic decisions.

This month’s expert: Wayne Higgins, director, NOAA’s Climate Prediction Center

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