December 2025 saw fairly standard conditions for the month on Grandfather Mountain, according to data recorded at the park’s official weather reporting stations.
The average high temperature for December 2025 was 38.43 degrees Fahrenheit, with an average low of 24.78 degrees and a mean of 31.60 degrees.
The warmest temperature recorded was 52.3 degrees on Dec. 27, just under 11 degrees shy of the mountain’s record December high of 63 degrees, observed Dec. 7, 1956. Generally, December sees winter weather conditions set in on Grandfather Mountain.
Dec. 14 saw the coldest temperature recorded last month with minus 2.4 degrees, breaking the daily low record for that day. The previous record for Dec. 14 was minus 1 degree, recorded in 1958.
A wind chill of minus 35.1 was also noted Dec. 14. A total of 12 days in December experienced a wind chill below zero. The lowest temperature ever observed on Grandfather Mountain in the month of December (not counting wind chill) was minus 21 degrees on Dec. 25, 1983.
The weather station on the Mile High Swinging Bridge noted 12 days in December with a wind gust higher than 60 mph. On Dec. 19, the weather station at the top recorded a wind gust of 94 mph, with a sustained wind speed clocking in at 58.2 mph that same day. The highest gust ever recorded on Grandfather Mountain was 124 mph, observed Feb. 25, 2019.
The weather station near the Swinging Bridge reported 2.92 inches of precipitation in December 2025. Precipitation at the top of the mountain includes rain and the liquid equivalent of any frozen precipitation (when applicable). The driest December on record was observed in 1965, when .55 inches were measured at the top. The mountain’s rainiest December was recorded in 2018, when 10.7 inches were measured.
There were 20 days of at least trace amounts of recorded liquid precipitation (rain and the liquid equivalent of frozen precipitation, when applicable) for December 2025. The record number of days for the month of December is 22 days, observed in 1972 and 1981. The December on record with the lowest number of days of precipitation is 2010, with only six days noted.
Observations recorded near the park’s Wilson Center for Nature Discovery totaled 2.89 inches of precipitation and also noted 6.6 inches of snowfall for the month. Precipitation is also measured at the latter location, as high winds can make it difficult to record accurate observations at the top. Due to wind, snow depth is not recorded at the top of the mountain.
The day last month with the highest amount of this precipitation observed was Dec. 19, when 1 inch was recorded at the top. The day with the highest amount of precipitation observed on record for December was Dec. 28, 1958, when the weather station noted 3.46 inches.
Weather Reporting
The Grandfather Mountain Stewardship Foundation records and reports data in two different ways:
- The park maintains an automated weather station at the top of the Mile High Swinging Bridge. The N.C. State Climate Office assists the foundation in calibrating the machines and ensuring overall accuracy of data.
- Grandfather Mountain has been an active member of the National Oceanic and Atmospheric Administration’s (NOAA) Cooperative Observer Program since 1955 by reporting weather data from locations near the Mile High Swinging Bridge and the Nature Museum (now the Wilson Center for Nature Discovery).
In the 69 years of weather collection at Grandfather Mountain, instrument locations for the Top Shop and Swinging Bridge area have moved around slightly as technology and understanding of what makes the best location for reporting have improved.
For more information on weather at Grandfather Mountain, visit www.grandfather.com/weather.