May 18 Weather at Raleigh-Durham International Airport North Carolina, United States

On May 18, the temperature at Raleigh-Durham International Airport typically ranges from 60°F to 78°F and is rarely below 49°F or above 87°F.

For reference, on July 19, the hottest day of the year, temperatures at Raleigh-Durham International Airport typically range from 71°F to 89°F, while on January 29, the coldest day of the year, they range from 33°F to 51°F.

The coolest time of the day is from 1:00 AM to 8:00 AM, with the coldest at 6:15 AM, at which time the temperature is below 65°F three days out of four, and below 68°F nine days out of ten.

The warmest time of the day is from 12:00 PM to 7:00 PM, with the hottest at 3:45 PM, at which time the temperature is above 73°F three days out of four, and above 66°F nine days out of ten.

The day has gained half its heat by 9:45 AM and lost it again by 9:00 PM.

The figure below shows you a compact characterization of the range of temperatures experienced on May 18 throughout the historical record. The horizontal axis is the time of day and the colored stacked areas indicate the percentage of hours spent in various temperature bands.

Shkodër, Albania (4,993 miles away) and Luoqiao, China (7,984 miles) are the far-away foreign places with temperatures most similar to Raleigh-Durham International Airport (view comparison).

Compared to May 18 (excluding 30 days before and after), September 24 has the most similar daily average high and low temperatures.

© OpenStreetMap contributors

Compare Raleigh-Durham International Airport to another city:

CompareMap

The average percentage of the sky covered by clouds at Raleigh-Durham International Airport on May 18 varies over the course of the day.

The cloudiest time of day is around 11:30 PM, at which time the chance of overcast or mostly cloudy conditions is 48%.

The clearest time of day is around 1:30 PM, at which time the chance of clear, mostly clear, or partly cloudy conditions is 59%.

For reference, on December 26, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 52%, while on October 11, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 65%.

On average, there is a 33% chance that more than 0.04 inches of total precipitation will fall at Raleigh-Durham International Airport throughout the day on May 18, all of which can be expected to be rain.

For reference, the year's highest daily chance of precipitation is 45% on July 16, and its lowest chance is 20% on October 30.

For those 33% of years with precipitation on May 18, the chart below shows when throughout the day that precipitation is more or less likely to occur, excluding hourly accumulations of less than 0.01 inches. If precipitation were equally likely throughout the day, all hours would report 4.2% (100% divided by 24 hours).

Precipitation is most likely between 2 PM and 3 PM, and least likely between 11 PM and 12 AM.

At Raleigh-Durham International Airport on Saturday, May 18, 2024, the Sun rises at 6:07 AM and sets 14 hours, 10 minutes later, at 8:16 PM. Solar noon is at 1:11 PM.

For reference, on June 20, the longest day of the year, the Sun rises at 5:59 AM and sets 14 hours, 36 minutes later, at 8:34 PM, while on December 21, the shortest day of the year, it rises at 7:21 AM and sets 9 hours, 43 minutes later, at 5:05 PM.

Civil twilight, the period before the Sun has risen or after the Sun has set during which time it is possible to engage in most outdoor activities without artificial lighting, begins and ends 29 minutes before sunrise and after sunset, at 5:38 AM and 8:45 PM respectively.

Nautical twilight, during which time it is possible to clearly discern the horizon (e.g., for navigational purposes), begins and ends 1 hour, 4 minutes before sunrise and after sunset, at 5:03 AM and 9:20 PM respectively.

Astronomical twilight, outside of which it is possible to make the most sensitive of astronomical observations, begins and ends 1 hour, 42 minutes before sunrise and after sunset, at 4:25 AM and 9:58 PM respectively.

At Raleigh-Durham International Airport on Saturday, May 18, 2024, the Moon sets at 3:31 AM and rises at 3:48 PM. The phase of the moon is waxing gibbous, with 78% of the disk illuminated.

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.

The chance of muggy, oppressive, or miserable conditions at Raleigh-Durham International Airport on May 18 varies over the course of the day, with an average daily chance of 19%.

The muggiest time of day on May 18 is around 11:30 AM, with muggy conditions 26% of the time.

The least muggy time of day is around 4:30 AM, with muggy conditions 14% of the time.

For reference, on July 23, the muggiest day of the year, there are muggy conditions 84% of the time, while on January 24, the least muggy day of the year, there are muggy conditions 0% of the time.

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 on May 18 varies throughout the day, with a daily average of 5.2 miles per hour.

The windiest time of day is around 2:45 PM, with an average hourly wind speed of 6.1 miles per hour, mostly staying between 4.2 miles per hour and 7.7 miles per hour, and rarely falling below 2.7 miles per hour or exceeding 9.7 miles per hour.

The calmest time of day is around 7:30 PM, with an average hourly wind speed of 4.0 miles per hour, mostly staying between 3.0 miles per hour and 4.7 miles per hour, and rarely falling below 2.4 miles per hour or exceeding 6.5 miles per hour.

For reference, on February 27, the windiest day of the year, the daily average wind speed is 6.5 miles per hour, while on August 8, the calmest day of the year, the daily average wind speed is 4.0 miles per hour.

Over the entire course of May 18 at Raleigh-Durham International Airport, the hourly average wind direction, in order of prevalence, is from the south (31%), west (30%), north (23%), and east (16%).

This section discusses the incident shortwave solar power 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 peak incident shortwave solar power per square meter is 0.82 kilowatts at around 1:15 PM.

In contrast, the corresponding value on June 22, the brightest day of the year, is 0.83 kilowatts at around 12:00 PM. The corresponding value on December 24, the darkest day of the year, is 0.41 kilowatts at around 11:15 AM.

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%).