The climate of North Carolina varies considerably from the Atlantic coast in the east to the Appalachian Mountains in the west. The mountains often act as a "shield", blocking low temperatures and storms from Canada and the Midwest from entering the Piedmont and Coastal Plain of North Carolina.North Carolina Department of the Secretary of State. North Carolina Climate & Geography. Retrieved on 2008-01-13.
Most of the state has a humid subtropical climate (Köppen climate classification Cfa), except in the higher elevations of the Appalachians which have a subtropical highland climate (Köppen Cfb).
The USDA Hardiness Zones for the state range from Zone 5B (-15 °F to -10 °F) in the mountains to Zone 9A (20 °F to 25 °F) along the easternmost portions of the coast.
For most areas of North Carolina, the temperatures in July during the daytime are approximately . In January, the average daytime temperatures can widely vary across the state, ranging from approximately 40 °F (4 °C) in the higher elevations of the Appalachians, near 50 °F (10 °C) in the Piedmont region, to around 60 °F (16 °C) along the southeastern coastal areas of the state.U.S. Travel Weather. North Carolina Weather. Retrieved on 2008-01-13.
Precipitation There is an average of of rain a year ( in the mountainous regions). July storms account for much of this precipitation. As much as 15 percent of the rainfall during the warm season in North Carolina can be attributed to tropical cyclones.David B. Knight Robert E. Davis. Retrieved on 2008-02-29. The western mountains usually see snowfall between November and March. Moist winds from the southwest drop an average of of precipitation on the western side of the mountains, while the northeast-facing slopes average less than half that amount.City-Data.com North Carolina - Climate Retrieved on 2008-02-09.
Average monthly precipitation City Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total AshevilleWeatherbase. Asheville, North Carolina Weather. Retrieved on 2008-02-08. Cape HatterasWeatherbase. Cape Hatteras, North Carolina Weather. Retrieved on 2008-02-08. CharlotteWeatherbase. Charlotte, North Carolina Weather. Retrieved on 2008-02-08. GreensboroWeatherbase. Greensboro, North Carolina Weather. Retrieved on 2024-05-09. RaleighWeatherbase. Raleigh, North Carolina Weather. Retrieved on 2008-02-08. WilmingtonWeatherbase. Wilmington, North Carolina Weather. Retrieved on 2008-02-08.
Snow
Snow in North Carolina is seen on a regular basis in the mountains. North Carolina averages of snow per winter season. However, this varies greatly across the state. Along the coast, most areas register less than per year while the state capital, Raleigh, averages . Farther west in the Piedmont-Triad, the average grows to approximately . The Charlotte area averages approximately . The town of Boone, North Carolina, located at an elevation of in the northwestern part of the state, receives on average nearly of snowfall annually. The mountains in the west act as a barrier, preventing most snowstorms from entering the Piedmont. When snow does make it past the mountains, it is usually light and is seldom on the ground for more than two or three days. However, several storms have dropped or more of snow within normally warm areas. The 1993 Storm of the Century that lasted from March 11 to March 15 affected locales from Canada to Central America, and brought exceptionally heavy snow to North Carolina. Newfound Gap received more than of snow with drifts more than , while Mount Mitchell measured over of snow with drifts to . Most of the northwestern part of the state received somewhere between and of snow.
Another significant snowfall hit the Raleigh area in January 2000 when more than of snow fell.Environmental Modeling Center. EMC MODEL GUIDANCE FOR THE BLIZZARD of 2000. Retrieved on 2008-02-09. There was also a heavy snowfall totaling that hit the Wilmington area on December 22–23, 1989. This storm affected only the Southeastern US coast, as far south as Savannah, Georgia, with little to no snow measured west of I-95. Most big snows that impact areas east of the mountains come from extratropical cyclones which approach from the south across Georgia and South Carolina and move off the coast of North or South Carolina. These storms typically throw Gulf or Atlantic moisture over cold Arctic air at ground level, usually propelled southward from Arctic high pressure over the Northeastern or New England states. If the storms track sufficiently far to the east, snow will be limited to the eastern part of the state (as with the December 22–23, 1989, storm, and the January 4, 2018, storm that dropped at Cape Hatteras, but virtually no snow in inland North Carolina locations). If the cyclones travel close to the coast, warm air will get pulled into eastern North Carolina due to increasing flow off the milder Atlantic Ocean, bringing a rain/snow line well inland with heavy snow restricted to the Piedmont, foothills and mountains, as with the January 22, 1987, storm that dropped at Charlotte. If the storm tracks inland into eastern North Carolina, the rain/snow line ranges between Raleigh and Greensboro. Average monthly snowfall City Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total Asheville - - - - - - Cape Hatteras - - - - - - - - Charlotte - - - - - - - Greensboro - - - - - - - Raleigh - - - - - - - Wilmington - - - - - - - -
Tropical cyclones
Located along the Atlantic Coast, many hurricanes that come up from the Caribbean Sea travel along the East Coast of the United States, passing by North Carolina.
On October 15, 1954, Hurricane Hazel struck North Carolina, at that time it was a Category 4 hurricane within the Saffir-Simpson Hurricane Scale. Hazel caused significant damage due to its strong winds. A weather station at Oak Island reported maximum sustained winds of , while in Raleigh winds of were measured. The hurricane caused 19 deaths and significant destruction. One person in Long Beach claimed that "of the 357 buildings that existed in the town, 352 were totally destroyed and the other five damaged". Hazel was described as "the most destructive storm in the history of North Carolina" in a 1989 report.State Climate Office of North Carolina. Research on North Carolina Severe Weather. Retrieved on 2008-03-09. Hazel remains the only Category 4 hurricane to ever make landfall in North Carolina.
In 1996, Hurricane Fran made landfall in North Carolina as a Category 3 hurricane. Fran caused significant wind and flood damage. Fran's maximum sustained wind speeds were , while North Carolina's coast saw surges of to above sea level. The amount of damage caused by Fran ranged from $1.275 to $2 billion in North Carolina.
In 2018, Hurricane Florence made landfall in North Carolina as a Category 1 hurricane. Although a low-end hurricane at landfall in terms of wind speed, the slow movement of Florence leading up to and following landfall contributed to the destructive persistence of rainbands over North Carolina between Wilmington and Elizabethtown. The training of rainbands over the same areas led to a swath of rainfall accumulations exceeding 30 inches (760 mm), and rainfall totals exceeded 10 inches (250 mm) over much of southeastern and south-central North Carolina. A maximum rainfall total of 35.93 inches (913 mm) was recorded around 7 miles (11 km) northwest of Elizabethtown, setting a new state record for the highest rainfall accumulation resulting from a tropical cyclone. The hurricane also produced 27 tornadoes across North Carolina. Damage statewide reached an estimated US $17 billion, more than the combined damage of Hurricane Floyd and Hurricane Matthew in the state, according to Governor Roy Cooper. Estimated insurance losses in North Carolina ranged between US $2.8-5 billion. Hurricane-related flooding damaged an estimated 75,000 structures, many of which had been previously damaged by Hurricane Matthew just two years prior.
In 2024, North Carolina was severely impacted by Hurricane Helene, primarily in its western Appalachian region, causing over 100 reported deaths and significant destruction of infrastructure and residential areas across multiple counties. After making landfall in the Big Bend region of Florida on September 27, the hurricane began to traverse over land across Georgia as a Category 2 hurricane and into the Appalachian mountain range as a strong tropical storm, bringing record rainfall to dozens of communities in western North Carolina, including Asheville, Boone, Chimney Rock, Lake Lure, Lansing, Montreat, and Swannanoa.
As a result of the historic rainfall, several rivers in the region overflowed and inundated entire communities, destroying homes and infrastructure, and severing power and communication services in several counties for prolonged periods. In addition, several dams were breached and mudslides occurred across the region, worsening existing damage.
According to meteorologist Ben Noll, Hurricane Helene released nearly 1.5 times more moisture in western North Carolina than in any prior previous recorded event in the region, with an estimated integrated vapor transport quantity of ~3,000 kilograms per meter per second. Helene surpassed the prior record of 1,883 kg/m/s. The amount of moisture and rainfall deposited in the region was considered exceptional due to its inland location, far from the East Coast and Gulf Coast.
The North Carolina State Climate Office at North Carolina State University reported that its Mount Mitchell weather station recorded of rainfall. The office referred to the total as "off the charts", comparing it to of rainfall being a once-in-1,000-year flood for the area. Asheville Regional Airport recorded of rainfall before a communication failure. A North Carolina Forest Service weather station recorded receiving of rain from September 25 to September 27, requiring further verification.
Rain Heavy rains accompany tropical cyclones and their remnants which move northeast from the Gulf of Mexico coastline, as well as inland from the western subtropical Atlantic Ocean. Over the past 30 years, the wettest tropical cyclone to strike the state was Hurricane Florence in September 2018, which dropped over of rainfall northwest of Elizabethtown. During hurricanes Hazel and Fran, the main force of destruction was from precipitation. Before Hurricane Floyd reached North Carolina, the state had already received large amounts of rain from Hurricane Dennis less than two weeks before Floyd. This saturated much of the western North Carolina soil and allowed heavy rains from Hurricane Floyd to turn into floods. Over 35 people died from Floyd. In the mountains, Hurricane Frances of September 2004 was nearly as wet, bringing over of rainfall to Mount Mitchell.
Severe weather In most years, the greatest weather-related economic loss incurred in North Carolina is due to severe weather spawned by summer thunderstorms. These storms affect limited areas, with their hail and wind accounting for an average annual loss of over US $5 million.State Climate Office of North Carolina. Overview. Retrieved on 2008-03-14.