May Weather in Charleston, United States

Last updated: February 24, 2025

In May, Charleston experiences a vibrant transition into summer, showcasing a maximum temperature reaching up to 37°C (98°F). The average temperature settles at a comfortable 23°C (74°F), while the nights can cool down to as low as 9°C (49°F). This month typically sees about 87 mm (3.4 in) of rainfall over 9 days, contributing to the region's lush greenery. With humidity levels hovering around 75%, visitors can expect a warm and slightly muggy atmosphere, perfect for enjoying Charleston’s rich history and inviting outdoor spaces.

May Temperature in Charleston

In May, Charleston experiences a delightful transition into warmer weather, with temperatures reflecting the city's vibrant atmosphere. The minimum temperature starts at a comfortable 9°C (49°F), while the average climbs to a pleasant 23°C (74°F), setting the stage for outdoor activities. As the month progresses, peaks can reach an impressive 37°C (98°F), creating the perfect backdrop for soaking up the southern sun. This significant increase from April not only suggests a shift towards summer but also invites locals and visitors alike to explore the city's charming streets and lush landscapes. Overall, May is marked by a delightful warmth, making it an ideal time to enjoy Charleston's unique blend of history and hospitality.

May Weather in Charleston: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Charleston, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec525760667479828178725954
Data source: Temperature data for Charleston generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

May Precipitation in Charleston

In May, Charleston experiences a moderate precipitation total of 87 mm (3.4 in), falling just short of the heavier rains seen in April. With nine days of rainfall, the month strikes a balance between the drier earlier months and the looming summer downpours. This trend hints at a transitional period, as the city prepares for the upcoming peak of the rainy season in June, which averages a significant jump to 150 mm (5.9 in) over 19 days. May's precipitation is characterized by consistent light showers rather than intense storms, allowing for lush greenery while still setting the stage for the wetter months ahead.

May Precipitation Trends in Charleston

The chart displays monthly precipitation patterns in Charleston, with values for each month alongside May's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec597860101871501871831767993127
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Charleston

In May, Charleston, United States, experiences a noticeable dip in humidity, resting at 75%, which marks the beginning of a subtle summer transition. This level is slightly lower than the 79% recorded in April, showcasing a trend of decreased humidity as the warmer months approach. Interestingly, Charleston's humidity in May is at its lowest compared to the months preceding and following it, with levels rising again as summer settles in—July and August see humidity levels soar to 80% and 81%, respectively. This gradual decrease in May provides a brief reprieve before the more humid summer months, making it a particularly pleasant time to enjoy the historic charm and vibrant outdoor life of Charleston.

May Average Humidity in Charleston

This chart illustrates the average monthly humidity levels in Charleston, with May's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how May's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec86%81%81%79%75%75%80%81%83%78%85%87%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Charleston

As May unfolds in Charleston, the UV Index reaches a peak of 11, signaling an extreme exposure category and a notably reduced burn time of just 10 minutes. This trend highlights a significant escalation from the moderate levels seen in January through to very high levels in March and April. With this increase, it's vital for residents and visitors alike to prioritize sun protection measures, ensuring they remain safe while enjoying the warm southern sunshine. This pattern of increasing UV intensity continues into June and July, making awareness and proactive protection all the more essential. For more details on managing UV exposure, visit Charleston UV Index.

Maximum UV Index Levels in Charleston for May

The chart shows the monthly maximum UV Index (UVI) for Charleston in May, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec47910111111119864
Data source: Charleston May UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

May Sunshine in Charleston

May shines brightly in Charleston, boasting an impressive 336 hours of sunshine. This delightful month stands out as a peak point in the year, with only July, at 341 hours, surpassing it. Transitioning from the cooler winter months, where January offers just 186 hours, the sunny days progressively increase; February brings 213 hours, and by April, residents enjoy 306 hours of light. As the warmth of summer approaches, May's vibrant sunshine invites locals and visitors alike to explore the city's historic charm and beautiful waterfront, setting the tone for an inviting summer atmosphere. This trend of increasing daylight not only illuminates Charleston but also uplifts the spirits of those who experience it.

Monthly Sunshine Duration in Charleston: May Highlighted

The May sunshine duration represents the total number of hours Charleston experiences direct sunlight during the month of May, excluding cloudy or obstructed periods. This chart compares the sunshine duration of May with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec186h213h275h306h336h316h341h314h300h288h247h217h
Data source: Charleston May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Charleston During May

In May, Charleston beckons with a 52% chance of sunny weather, making it a delightful time to enjoy the outdoors. This slight dip from April's 56% suggests a minor shift as spring transitions toward summer, yet it remains a promising month for sunshine. Looking at the broader trends, we see a gradual decrease in sunny probabilities as the summer months approach, with June plummeting to 29%. Meanwhile, May stands out as a favorable time, sandwiched between the vibrant spring and the potential humidity of summer. With a beautiful mix of mild temperatures and ample sun, May is indeed a lovely window for those yearning for a taste of Charleston's charm.

Percentage of Sunny Days in May in Charleston

The chart illustrates the percentage of sunny days in Charleston throughout the year, with May highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Charleston experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec45%39%38%56%52%29%34%30%51%50%62%45%
Data source: Charleston May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Charleston in May

As spring transitions into summer in Charleston, the city experiences a notable increase in daylight hours. In January, residents enjoy around 10 hours of daylight, slowly increasing to 11 hours by February and March. By April, the days lengthen to 13 hours, signaling the arrival of warmer weather and outdoor activities. Interestingly, May maintains this 13-hour daylight mark, providing ample time for residents to bask in the sun before the summer months kick in. In June and July, Charleston reaches its peak with 14 hours of daylight, allowing for extended evenings filled with vibrant sunsets and social gatherings. As August approaches, daylight begins to wane slightly to 13 hours, with a gradual decline through the autumn months, ultimately returning to 10 hours by December. This rhythm of daylight reflects both the changing seasons and the lifestyle shifts of Charleston's community.

Average Daylight Hours in Charleston for May

The chart illustrates the variation in daylight duration in Charleston throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 14m11h11h 59m13h13h 51m14h 16m14h 2m13h 17m12h 19m11h 19m10h 26m10h
Data source: Charleston daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in Charleston

In May, Charleston enjoys a refreshing average wind speed of 4.0 m/s (9 mph), maintaining a delightful breeze that lingers from the spring months. This slight uptick from April's 3.9 m/s contributes to the city's vibrant atmosphere, as residents and visitors alike revel in outdoor activities amid balmy temperatures. As the weather warms, the winds begin to ease into summer, with June typically experiencing a decrease, settling to an average of 3.7 m/s (8 mph). This trend reflects a gradual transition, inviting a more laid-back pace as the summer heat sets in. Such gentle winds in May help showcase Charleston's enchanting scenery while encouraging leisurely strolls and outdoor gatherings.

Average May Wind Speed in Charleston

The chart displays monthly wind speed patterns in Charleston, with values for each month shown alongside May's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how May's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec3.93.84.03.94.0 m/s3.73.22.82.93.23.63.5
Data source: Charleston May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in Charleston Compares to Other Months

The weather in Charleston changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of May's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Charleston and find detailed weather information for every month.

In comparing the weather between May and January, there is a stark contrast in temperature and conditions. May boasts a comfortable average temperature of 23°C (74°F) with highs reaching up to 37°C (98°F), while January experiences much cooler temperatures with an average of 11°C (52°F) and lows plunging to -13°C (9°F). Precipitation is slightly higher in May at 87 mm (3.4 in) over 9 days, compared to January's 59 mm (2.3 in) across 7 days. Additionally, humidity levels are generally high in both months, with January being slightly more humid at 86% compared to May's 75%. For more detailed insights on January weather patterns, you can visit Charleston weather in January.

May and February present contrasting weather patterns. In May, temperatures range from a minimum of 9°C (49°F) to a scorching maximum of 37°C (98°F), with an average temperature of 23°C (74°F). The month experiences about 87 mm (3.4 in) of precipitation over 9 days, alongside a humidity level of 75%. In comparison, February is much cooler, with temperatures ranging from a chilly -2°C (29°F) to a mild maximum of 26°C (79°F), averaging at 14°C (57°F). Precipitation in February is slightly less at 78 mm (3.1 in) over the same 9 days, but the humidity is higher at 81%. For more insights on February's weather, check out Charleston weather in February.

May and March present distinct climate profiles, showcasing the transition from early spring to late spring. In March, temperatures range from a chilly minimum of -1°C (30°F) to a comfortable average of 15°C (60°F), with a maximum reaching 28°C (82°F). The month experiences around 60 mm (2.4 in) of precipitation over 6 days, providing a relatively mild and slightly humid atmosphere with 81% humidity. In contrast, May boasts a much warmer climate, with temperatures ranging from a minimum of 9°C (49°F) to an average of 23°C (74°F), and highs soaring up to 37°C (98°F). Although May sees more precipitation at 87 mm (3.4 in) over 9 days, it maintains a slightly lower humidity level of 75%. For more detailed information, you can check Charleston weather in March.

In comparing the weather between April and May, we see a notable rise in temperature as spring transitions into early summer. May experiences a minimum temperature of 9°C (49°F), an average of 23°C (74°F), and peaks at 37°C (98°F), while April's temperatures range from a minimum of 4°C (39°F) to a maximum of 31°C (89°F), with an average of 19°C (66°F). Precipitation in April is slightly higher at 101 mm (4.0 in) over 8 days, compared to May's 87 mm (3.4 in) over 9 days. Additionally, humidity remains relatively high in both months, with April at 79% and May at 75%. For more detailed information, you can refer to Charleston weather in April.

In comparing the weather between May and June, it's clear that June generally presents warmer temperatures, with a minimum of 16°C (61°F) and an average of 26°C (79°F), compared to May's minimum of 9°C (49°F) and average of 23°C (74°F). Although June's maximum temperature reaches 35°C (95°F), it falls slightly short of May's peak of 37°C (98°F). However, June experiences significantly more precipitation, with 150 mm (5.9 in) over 19 days, compared to May's 87 mm (3.4 in) over just 9 days. Despite both months having the same humidity level of 75%, the increased rainfall in June may lead to more cloudy days. For a closer look at June's weather conditions, you can explore Charleston weather in June.

May and July exhibit notable differences in weather patterns, highlighting the transition from late spring to peak summer. In May, temperatures range from a minimum of 9°C (49°F) to a maximum of 37°C (98°F), with an average of 23°C (74°F). The month sees around 87 mm (3.4 in) of precipitation over 9 days, coupled with a humidity level of 75%. In contrast, July experiences milder minimum temperatures at 20°C (69°F) and a lower maximum of 34°C (94°F), with an average of 28°C (82°F). However, it brings increased rainfall, totaling 187 mm (7.4 in) over 20 days, and slightly higher humidity at 80%. For more detailed information on July’s weather, you can visit Charleston weather in July.

May and August exhibit notable differences in weather patterns. May offers a wider temperature range with a minimum of 9°C (49°F) and a maximum of 37°C (98°F), averaging around 23°C (74°F). In contrast, August presents a milder minimum temperature of 21°C (70°F) and a lower maximum of 35°C (95°F), with an average of 27°C (81°F). Precipitation also varies significantly; May receives 87 mm (3.4 in) over roughly 9 days, whereas August sees a substantial increase to 183 mm (7.2 in) over 21 days, contributing to higher humidity levels in August at 81% compared to 75% in May. For more detailed insights about the weather in August, you can visit Charleston weather in August.

May and September present contrasting weather patterns, with May typically offering a warmer range of temperatures, from a minimum of 9°C (49°F) to a maximum of 37°C (98°F). The average temperature in May is 23°C (74°F), accompanied by relatively lower precipitation at 87 mm (3.4 in) over about nine rainy days and humidity levels around 75%. In contrast, September experiences a slightly higher average temperature of 26°C (78°F), with minimum and maximum temperatures ranging from 14°C (57°F) to 35°C (94°F). However, it also sees increased precipitation, totaling 176 mm (6.9 in) over about 14 days, and higher humidity at 83%. This shift in weather underscores the transition from late spring warmth to early autumn conditions. For more insights, you can check Charleston weather in September.

In May, temperatures range from a minimum of 9°C (49°F) to a maximum of 37°C (98°F), with an average temperature of 23°C (74°F). The month experiences about 87 mm (3.4 in) of precipitation spread over 9 days, accompanied by a humidity level of 75%. In contrast, October offers cooler weather, with temperatures ranging from a minimum of 3°C (38°F) to a maximum of 31°C (89°F) and an average of 22°C (72°F). October's precipitation is slightly lower at 79 mm (3.1 in) over the same number of days, and humidity is marginally higher at 78%. For more details on what to expect, check out Charleston weather in October.

May and November present distinctly different weather patterns. In May, temperatures range from a minimum of 9°C (49°F) to a scorching maximum of 37°C (98°F), with an average temperature of 23°C (74°F). This month experiences approximately 87 mm (3.4 in) of precipitation over about 9 days, maintaining a humidity level of 75%. In contrast, November showcases a cooler climate, with temperatures ranging from a minimum of -1°C (31°F) to a maximum of 28°C (84°F), averaging around 15°C (59°F). The month sees similar precipitation levels at 92 mm (3.6 in) over 8 days, but with a higher humidity of 85%. For those interested in weather specifics for Charleston in November, more details can be found at Charleston weather in November. Overall, May is marked by heat and humidity, while November offers a cooler and slightly wetter climate.

May and December exhibit distinct weather characteristics that cater to different preferences. In May, temperatures range from a mild minimum of 9°C (49°F) to a maximum of 37°C (98°F), with an average temperature of 23°C (74°F). The month sees about 87 mm (3.4 in) of precipitation over 9 days and maintains a humidity level of 75%. In contrast, December experiences cooler temperatures, with a minimum of -3°C (28°F) and a maximum of 25°C (77°F), averaging at 12°C (54°F). This month sees increased precipitation of 127 mm (5.0 in) over the same number of days, alongside higher humidity at 87%. For more details on December's climate, you can view Charleston weather in December.

Compare Charleston's Climate with Cities Worldwide

Conclusion: What to Expect From May Weather in Charleston

As spring blossoms into early summer, Charleston's May weather showcases a delightful mix of warmth and humidity, setting the stage for vibrant outdoor activities. With temperatures averaging a comfortable 23°C (74°F) and highs reaching up to a sizzling 37°C (98°F), this month stands out from the cooler spring months while still offering refreshing evenings. However, be prepared for the occasional rain, as May also sees an increase in precipitation days, totaling around 9 days throughout the month. The humidity, hovering around 75%, can make those warm days feel a bit stickier, yet it adds to the lush beauty of the season. For more insights on how Charleston's climate shifts with the seasons, check out Charleston Climate.