May 2025 was a wet month on Grandfather Mountain, according to data recorded at the park’s official weather reporting stations, with one precipitation record broken.
The average high temperature for May 2025 was 57.33 degrees Fahrenheit, with an average low of 46.34 degrees and a mean of 51.84 degrees.
The warmest temperature recorded last month was 68.9 degrees on May 15, more than 9 degrees shy of the mountain’s record May high of 78 degrees, observed on May 19, 1996.
Generally, May sees spring-like weather conditions arrive on Grandfather Mountain, though some chilly temperatures can still persist. May 23 saw the coldest temperature recorded last month with 35.8 degrees. The lowest temperature ever observed on Grandfather Mountain in the month of May (not counting wind chill) was 15 degrees on May 6, 1957.
The weather station on the Mile High Swinging Bridge noted six days in May with a wind gust higher than 60 mph. On May 17, the weather station at the top recorded a wind gust of 82.1 mph, while the month’s highest recorded sustained wind speed clocked in at 49.8 mph on May 22. The highest gust ever recorded on Grandfather Mountain was 124 mph, observed Feb. 25, 2019.
The weather station near the Swinging Bridge reported 11.15 inches of precipitation in May 2025, the fourth-highest total for this month on record. Precipitation at the top of the mountain includes rain and the liquid equivalent of any frozen precipitation (when applicable).
Observations recorded near the park’s Wilson Center for Nature Discovery totaled 13.8 inches of precipitation 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.
The mountain’s rainiest May was recorded in 2018, when 19.70 inches were observed near the bridge. That year saw widespread flooding and damage across the region from Tropical Storm Alberto. The driest May on record was observed in 2007, when 1.43 inches were measured at the top.
There were 23 days of at least trace amounts of recorded liquid precipitation (rain and the liquid equivalent of frozen precipitation, when applicable) for May 2025, two days short of the record 25 days in 2009.
The day last month with the highest amount of this precipitation observed was May 13, when 4.71 inches were recorded at the top. This amount is a new record, surpassing the former total for the most rain in one day in May of 4.67 inches, measured on May 28, 1973.
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).
For more information on weather at Grandfather Mountain, visit www.grandfather.com/weather.