Greensboro, like much of the southeastern United States, has a humid subtropical climate (Köppen Cfa), with four distinct seasons. Winters are short and generally cool, with a January daily average of 38.9 °F (3.8 °C). On average, there are 75 nights per year that drop to or below freezing,[a] and 4.3 days that fail to rise above freezing.[b] Measurable snowfall occurs nearly every winter, and accumulates to a normal of 7.5 inches (19.1 cm), usually in January and February and occasionally December and March; the actual amount may vary considerably from winter to winter.[c] Cold-air damming (CAD) can facilitate freezing rain, often making it a more pressing concern than snow. Summers are hot and humid, with a daily average in July of 78.5 °F (25.8 °C). There is an average 32 days per year with highs at or above 90 °F (32 °C), but, as in much of the Piedmont South, 100 °F (38 °C)+ readings are uncommon. Autumn is similar to spring in temperature but has fewer days of rainfall and less total rainfall. Extremes in temperature have ranged from −8 °F (−22 °C) on January 21, 1985, up to 104 °F (40 °C), on July 17, 1914.
Greenboro has a humid subtropical climate, typical for its latitude. It is characterized by four distinct seasons and high humidity year round. The area’s position on the Appalachian Mountains also contributes to some occasional cold winter air descending from the north, but Greenboro is generally milder than many other cities located at similar latitudes in the US. Hurricanes are rare due to the city’s location away from the Atlantic coastline and additionally out of the path of hurricanes traversing up either coast. The Appalachian Mountains also help protect Greenboro from potential cold air outbreaks from Canada, which contribute to the city’s moderately cool fall temperatures. Summers are hot and humid, with frequent afternoon thunderstorms. The daily average temperature in July is 81.7 °F (27.6 °C), with high temperatures reaching 90-100 °F (32-38 °C) approximately 43 days out of the year; however, partially due to the significant elevation changes in the area, morning relative humidity levels mean that actual ‘feels like’ temperatures are usually 10–15 degrees cooler than the reported temperature. On average, Greenboro receives about 46 inches (1143 mm) of precipitation per year; snowfall averages 3–4 inches (8 cm).
Greenboro’s lowest recorded temperature is 5 degrees Fahrenheit (-15 degrees Celsius), on January 21, 1985. Greenboro’s highest recorded temperature was 106 degrees Fahrenheit (41 degrees Celsius), on July 21, 1983.
The average number of days with any measurable precipitation is 85. On average, there are 212 sunny days per year in Greenboro. The July high averages around 86% possible sunshine while the December low sees about 33% possible sunshine. Greenboro lies within USDA Plant Hardiness Zone 7a or Sunset zone 4.
Thunderstorms are common during the humid spring and summer months, some being severe. On April 2, 1936, at around 7:00 pm, a large, F-4 tornado cut a seven-mile (11 km) swath of destruction through southern Greensboro. 14 people were killed and 144 were injured from the tornado, which moved through part of downtown. The storm was part of an outbreak known as the 1936 Cordele-Greensboro tornado outbreak. Strong tornadoes have struck the Greensboro area since then, notably Stoneville on March 20, 1998; Clemmons and Winston-Salem on May 5, 1989; Clemmons and Greensboro on May 7, 2008; High Point on March 28, 2010; and Greensboro on April 15, 2018.