Climate and Average Weather Year Round at Raleigh-Durham International Airport North Carolina, United States

At Raleigh-Durham International Airport, the summers are hot and muggy, the winters are short and very cold, and it is wet and partly cloudy year round. Over the course of the year, the temperature typically varies from 33°F to 89°F and is rarely below 19°F or above 95°F.

Based on the tourism score, the best times of year to visit Raleigh-Durham International Airport for warm-weather activities are from early May to mid June and from late August to mid October.

The hot season lasts for 3.6 months, from May 27 to September 15, with an average daily high temperature above 81°F. The hottest month of the year at Raleigh-Durham International Airport is July, with an average high of 89°F and low of 70°F.

The cool season lasts for 3.0 months, from December 1 to February 28, with an average daily high temperature below 58°F. The coldest month of the year at Raleigh-Durham International Airport is January, with an average low of 33°F and high of 51°F.

At Raleigh-Durham International Airport, the average percentage of the sky covered by clouds experiences mild seasonal variation over the course of the year.

The clearer part of the year at Raleigh-Durham International Airport begins around July 29 and lasts for 3.8 months, ending around November 24.

The clearest month of the year at Raleigh-Durham International Airport is October, during which on average the sky is clear, mostly clear, or partly cloudy 64% of the time.

The cloudier part of the year begins around November 24 and lasts for 8.2 months, ending around July 29.

The cloudiest month of the year at Raleigh-Durham International Airport is January, during which on average the sky is overcast or mostly cloudy 50% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at Raleigh-Durham International Airport varies throughout the year.

The wetter season lasts 3.6 months, from May 11 to August 30, with a greater than 32% chance of a given day being a wet day. The month with the most wet days at Raleigh-Durham International Airport is July, with an average of 13.5 days with at least 0.04 inches of precipitation.

The drier season lasts 8.4 months, from August 30 to May 11. The month with the fewest wet days at Raleigh-Durham International Airport is November, with an average of 6.4 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone at Raleigh-Durham International Airport is July, with an average of 13.5 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 45% on July 15.

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Raleigh-Durham International Airport experiences some seasonal variation in monthly rainfall.

Rain falls throughout the year at Raleigh-Durham International Airport. The month with the most rain at Raleigh-Durham International Airport is August, with an average rainfall of 4.0 inches.

The month with the least rain at Raleigh-Durham International Airport is November, with an average rainfall of 2.7 inches.

Snowfall

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Raleigh-Durham International Airport experiences some seasonal variation in monthly snowfall.

The snowy period of the year lasts for 3.1 months, from December 10 to March 14, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow at Raleigh-Durham International Airport is February, with an average snowfall of 3.4 inches.

The snowless period of the year lasts for 8.9 months, from March 14 to December 10. The least snow falls around July 23, with an average total accumulation of 0.0 inches.

The length of the day at Raleigh-Durham International Airport varies significantly over the course of the year. In 2025, the shortest day is December 21, with 9 hours, 43 minutes of daylight; the longest day is June 20, with 14 hours, 36 minutes of daylight.

The earliest sunrise is at 5:58 AM on June 13, and the latest sunrise is 1 hour, 40 minutes later at 7:37 AM on November 1. The earliest sunset is at 5:01 PM on December 5, and the latest sunset is 3 hours, 35 minutes later at 8:35 PM on June 28.

Daylight saving time (DST) is observed at Raleigh-Durham International Airport during 2025, starting in the spring on March 9, lasting 7.8 months, and ending in the fall on November 2.

The figure below presents a compact representation of key lunar data for 2025. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

Raleigh-Durham International Airport experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 4.5 months, from May 20 to October 2, during which time the comfort level is muggy, oppressive, or miserable at least 21% of the time. The month with the most muggy days at Raleigh-Durham International Airport is July, with 24.7 days that are muggy or worse.

The month with the fewest muggy days at Raleigh-Durham International Airport is February, with 0.0 days that are muggy or worse.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed at Raleigh-Durham International Airport experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 6.3 months, from November 5 to May 15, with average wind speeds of more than 5.3 miles per hour. The windiest month of the year at Raleigh-Durham International Airport is March, with an average hourly wind speed of 6.5 miles per hour.

The calmer time of year lasts for 5.7 months, from May 15 to November 5. The calmest month of the year at Raleigh-Durham International Airport is August, with an average hourly wind speed of 4.1 miles per hour.

The predominant average hourly wind direction at Raleigh-Durham International Airport varies throughout the year.

The wind is most often from the west for 2.0 weeks, from January 7 to January 21; for 1.6 weeks, from March 18 to March 29; for 1.3 weeks, from April 30 to May 9; and for 1.7 months, from June 3 to July 25, with a peak percentage of 36% on July 13. The wind is most often from the north for 1.9 months, from January 21 to March 18 and for 4.0 months, from September 8 to January 7, with a peak percentage of 34% on January 29. The wind is most often from the south for 1.0 months, from March 29 to April 30; for 3.6 weeks, from May 9 to June 3; and for 1.0 months, from July 25 to August 26, with a peak percentage of 33% on July 31.

To characterize how pleasant the weather is at Raleigh-Durham International Airport throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best times of year to visit Raleigh-Durham International Airport for general outdoor tourist activities are from early May to mid June and from late August to mid October, with a peak score in the third week of September.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Raleigh-Durham International Airport for hot-weather activities is from mid June to mid September, with a peak score in the second week of August.

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

The growing season at Raleigh-Durham International Airport typically lasts for 7.2 months (221 days), from around March 30 to around November 6, rarely starting before March 8 or after April 21, and rarely ending before October 19 or after November 25.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

Based on growing degree days alone, the first spring blooms at Raleigh-Durham International Airport should appear around February 16, only rarely appearing before January 28 or after March 8.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences significant seasonal variation over the course of the year.

The brighter period of the year lasts for 4.1 months, from April 15 to August 20, with an average daily incident shortwave energy per square meter above 5.9 kWh. The brightest month of the year at Raleigh-Durham International Airport is June, with an average of 6.8 kWh.

The darker period of the year lasts for 2.9 months, from November 9 to February 7, with an average daily incident shortwave energy per square meter below 3.3 kWh. The darkest month of the year at Raleigh-Durham International Airport is December, with an average of 2.5 kWh.

For the purposes of this report, the geographical coordinates of Raleigh-Durham International Airport are 35.879 deg latitude, -78.787 deg longitude, and 407 ft elevation.

The topography within 2 miles of Raleigh-Durham International Airport contains only modest variations in elevation, with a maximum elevation change of 190 feet and an average elevation above sea level of 371 feet. Within 10 miles also contains only modest variations in elevation (449 feet). Within 50 miles contains only modest variations in elevation (968 feet).

The area within 2 miles of Raleigh-Durham International Airport is covered by artificial surfaces (72%) and trees (25%), within 10 miles by artificial surfaces (57%) and trees (39%), and within 50 miles by trees (57%) and cropland (31%).