Average Weather at Charleston, Navelexcen South Carolina, United States
At Charleston, Navelexcen, the summers are hot and oppressive, the winters are short and cold, and it is wet and partly cloudy year round. Over the course of the year, the temperature typically varies from 40°F to 90°F and is rarely below 27°F or above 96°F.
Based on the tourism score, the best times of year to visit Charleston, Navelexcen for warm-weather activities are from mid April to late May and from late September to late October.
The hot season lasts for 3.7 months, from May 24 to September 15, with an average daily high temperature above 84°F. The hottest day of the year is July 19, with an average high of 90°F and low of 76°F.
The cool season lasts for 3.0 months, from November 30 to February 28, with an average daily high temperature below 65°F. The coldest day of the year is January 17, with an average low of 40°F and high of 59°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
At Charleston, Navelexcen, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year at Charleston, Navelexcen begins around September 13 and lasts for 2.9 months, ending around December 10. On October 27, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 66% of the time, and overcast or mostly cloudy 34% of the time.
The cloudier part of the year begins around December 10 and lasts for 9.1 months, ending around September 13. On July 27, the cloudiest day of the year, the sky is overcast or mostly cloudy 56% of the time, and clear, mostly clear, or partly cloudy 44% of the time.
Cloud Cover Categories
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at Charleston, Navelexcen varies significantly throughout the year.
The wetter season lasts 3.5 months, from May 31 to September 15, with a greater than 35% chance of a given day being a wet day. The chance of a wet day peaks at 51% on August 5.
The drier season lasts 8.5 months, from September 15 to May 31. The smallest chance of a wet day is 19% on October 30.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 51% on August 5.
Daily Chance of Precipitation
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. Charleston, Navelexcen experiences significant seasonal variation in monthly rainfall.
Rain falls throughout the year at Charleston, Navelexcen. The most rain falls during the 31 days centered around August 18, with an average total accumulation of 5.2 inches.
The least rain falls around November 11, with an average total accumulation of 2.3 inches.
Average Monthly Rainfall
The length of the day at Charleston, Navelexcen varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 59 minutes of daylight; the longest day is June 21, with 14 hours, 20 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 6:10 AM on June 12, and the latest sunrise is 1 hour, 29 minutes later at 7:39 AM on November 3. The earliest sunset is at 5:13 PM on December 4, and the latest sunset is 3 hours, 19 minutes later at 8:32 PM on June 29.
Daylight saving time (DST) is observed at Charleston, Navelexcen during 2018, starting in the spring on March 11, lasting 7.8 months, and ending in the fall on November 4.
Sunrise & Sunset with Twilight and Daylight Saving Time
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.
Charleston, Navelexcen experiences extreme seasonal variation in the perceived humidity.
The muggier period of the year lasts for 5.7 months, from May 3 to October 24, during which time the comfort level is muggy, oppressive, or miserable at least 25% of the time. The muggiest day of the year is July 22, with muggy conditions 98% of the time.
The least muggy day of the year is January 31, with muggy conditions 1% of the time.
Humidity Comfort Levels
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
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 Charleston, Navelexcen experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 6.3 months, from November 2 to May 12, with average wind speeds of more than 7.6 miles per hour. The windiest day of the year is February 26, with an average hourly wind speed of 8.9 miles per hour.
The calmer time of year lasts for 5.7 months, from May 12 to November 2. The calmest day of the year is August 17, with an average hourly wind speed of 6.3 miles per hour.
Average Wind Speed
The predominant average hourly wind direction at Charleston, Navelexcen varies throughout the year.
The wind is most often from the west for 2.3 months, from January 8 to March 17, with a peak percentage of 36% on January 20. The wind is most often from the south for 5.3 months, from March 17 to August 27, with a peak percentage of 51% on July 16. The wind is most often from the north for 3.3 months, from September 29 to January 8, with a peak percentage of 36% on January 1.
Charleston, Navelexcen is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average water temperature experiences some seasonal variation over the course of the year.
The time of year with warmer water lasts for 3.4 months, from June 14 to September 28, with an average temperature above 79°F. The day of the year with the warmest water is August 4, with an average temperature of 83°F.
The time of year with cooler water lasts for 4.0 months, from December 20 to April 21, with an average temperature below 67°F. The day of the year with the coolest water is March 6, with an average temperature of 63°F.
Average Water Temperature
Best Time of Year to Visit
To characterize how pleasant the weather is at Charleston, Navelexcen 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 Charleston, Navelexcen for general outdoor tourist activities are from mid April to late May and from late September to late October, with a peak score in the first week of May.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best times of year to visit Charleston, Navelexcen for hot-weather activities are from mid May to early July and from mid August to late September, with a peak score in the first week of September.
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 Charleston, Navelexcen typically lasts for 9.4 months (284 days), from around February 26 to around December 7, rarely starting before February 3 or after March 21, and rarely ending before November 17 or after December 29.
Time Spent in Various Temperature Bands and the Growing Season
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
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 Charleston, Navelexcen should appear around January 22, only rarely appearing before January 14 or after February 8.
Growing Degree Days
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 3.0 months, from April 7 to July 7, with an average daily incident shortwave energy per square meter above 5.9 kWh. The brightest day of the year is May 14, with an average of 6.7 kWh.
The darker period of the year lasts for 2.8 months, from November 11 to February 5, with an average daily incident shortwave energy per square meter below 3.5 kWh. The darkest day of the year is December 21, with an average of 2.7 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Charleston, Navelexcen are 32.916 deg latitude, -79.979 deg longitude, and 16 ft elevation.
The topography within 2 miles of Charleston, Navelexcen is essentially flat, with a maximum elevation change of 62 feet and an average elevation above sea level of 18 feet. Within 10 miles is essentially flat (151 feet). Within 50 miles also contains only modest variations in elevation (302 feet).
The area within 2 miles of Charleston, Navelexcen is covered by artificial surfaces (55%) and herbaceous vegetation (30%), within 10 miles by artificial surfaces (47%) and herbaceous vegetation (26%), and within 50 miles by water (39%) and trees (34%).
This report illustrates the typical weather at Charleston, Navelexcen, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
Charleston, Navelexcen has a weather station that reported reliably enough during the analysis period that we have included it in our network. When available, historical temperature and dew point measurements are taken directly from this weather station. These records are obtained from NOAA's Integrated Surface Hourly data set, falling back on ICAO METAR records as required.
In the case of missing or erroneous measurements from this station, we fall back on records from nearby stations, adjusted according to typical seasonal and diurnal intra-station differences. For a given day of the year and hour of the day, the fallback station is selected to minimize the prediction error over the years for which there are measurements for both stations.
The stations on which we may fall back include but are not limited to Charleston NAS, Charleston International Airport, Charleston Executive Airport, Berkeley County Airport, Summerville Airport, Lowcountry Regional Airport, Santee Cooper Regional Airport, and Georgetown County Airport.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.
The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.
We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.
We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.