![]() Heavy snow (more than 10 inches in some locations) and severe icing caused widespread damage. In the northwest, temperatures remained below freezing for 8 consecutive days and fell to around 0☏. While the recent trend is toward fewer extremely cold events, a historic cold wave affected the state during February 11–20, 2021. ![]() The number of freezing days was mostly well above average between 19 but has been highly variable since then (Figure 2b). Since 2005, summer temperatures have been above average, but the highest multiyear average occurred during the 1950–1954 period (Figure 4). During the last 11 years, the number of very warm nights has been above average, with the 2010–2014 multiyear average exceeding that of previous multiyear-year periods (Figure 3). The number of extremely hot days was generally above average in the first half of the 20th century, but since 1955, the number of these days has generally been below average (Figure 2a). Hypothesized causes for this difference in warming rates include increased cloud cover and precipitation, increased small particles from coal burning, natural factors related to forest regrowth, decreased heat flux due to irrigation, and multidecadal variability in North Atlantic and tropical Pacific sea surface temperatures. The contiguous United States as a whole has warmed by about 1.8☏ since 1900, with only slight cooling from the 1930s into the 1960s. Temperatures have risen since that cool period by more than 2☏. Temperatures in Mississippi were above average in the 1920s, 1930s, and 1950s, followed by a substantial cooling of almost 2☏ throughout the 1960s and 1970s. Mississippi is one of the few areas globally to experience little net warming (Figure 1). The warmest consecutive 5-year interval was the most recent, 2016–2020. Temperatures in Mississippi have risen by a miniscule 0.1☏ since the beginning of the 20th century, but recent years have been very warm. Less warming is expected under a lower emissions future (the coldest end-of-century projected years being about as warm as the hottest year in the historical record green shading) and more warming under a higher emissions future (the hottest end-of-century projected years being about 11☏ warmer than the hottest year in the historical record red shading). ![]() Historically unprecedented warming is projected during this century. Observed temperatures are generally within, but on the low end of, the envelope of model simulations of the historical period (gray shading). Shading indicates the range of annual temperatures from the set of models. Mississippi is one of the few areas globally to experience little net warming. Temperatures in Mississippi (orange line) have risen by a miniscule 0.1☏ since the beginning of the 20th century, but recent years have been very warm. Projected changes for 2006–2100 are from global climate models for two possible futures: one in which greenhouse gas emissions continue to increase (higher emissions) and another in which greenhouse gas emissions increase at a slower rate (lower emissions). Extreme temperatures range from a record low of −19☏ at Corinth (January 30, 1966) to a record high of 115☏ at Holly Springs (July 29, 1930).įigure 1: Observed and projected changes (compared to the 1901–1960 average) in near-surface air temperature for Mississippi. Statewide annual average (1991–2020 normals) precipitation is 55.9 inches and ranges from 50 inches in the north to about 65 inches along the coast. This mild climate is an important economic driver for agricultural production and tourism. In addition to serving as a predominant source of moisture, the warm waters of the Gulf of Mexico help moderate temperatures along Mississippi’s coast. Thus, Mississippi’s climate is characterized by relatively mild winters, hot summers, and year-round precipitation. Clockwise circulation of air around a semipermanent high-pressure system in the North Atlantic (the Bermuda High) causes a quite persistent southerly flow of air off the Gulf during the warmer half of the year. The state is therefore exposed to diverse air masses, including the warm, moist air from the Gulf of Mexico and drier continental air masses, which are cold in the winter and warm in the summer. Mississippi is located between the Gulf of Mexico and the southern end of the vast, relatively flat plains of central North America, which extend from the Arctic Circle to the Gulf of Mexico.
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