Last updated: February 24, 2025
Discover the delightful May weather in National Harbor, United States, where temperatures range from a charming minimum of 3°C (37°F) to a soaring maximum of 35°C (95°F). The average temperature settles at a comfortable 19°C (67°F), making it an ideal time for outdoor activities. While May brings with it 121 mm (4.8 in) of rain spread over 12 days, the humidity hovers around 78%, adding a refreshing feel to the warm air. Whether you're exploring the waterfront or indulging in local festivities, National Harbor's May climate offers a vibrant setting for a memorable experience.
In May, National Harbor experiences a delightful transition into warmer weather, with temperatures showcasing a noticeable climb. The minimum temperature settles around 3°C (37°F), setting the stage for pleasant days ahead. The average temperature of 19°C (67°F) makes this month ideal for outdoor activities, as the environment shifts towards the warmth of summer. The maximum temperature can reach a sizzling 35°C (95°F), hinting at the heat that will soon envelop the region. This month is characterized by a healthy blend of mild mornings and sweltering afternoons, highlighting the gradual seasonal shift that brings life back to the area. As May unfolds, visitors can look forward to vibrant days filled with sunshine, perfect for enjoying all that National Harbor has to offer.
In May, National Harbor experiences a notable uptick in precipitation, with 121 mm (4.8 in) of rain falling over an average of 12 days. This marks an increase from the previous months, reflecting a trend of escalating rainfall as spring transitions into summer. The month of May not only showcases the highest precipitation for the year up to this point, but it also signals the peak of the wet season leading into the summer months. Following May, the rainfall continues to rise in June and July, with June contributing 107 mm (4.2 in) and July reaching 132 mm (5.2 in), further solidifying the region's shift towards a wetter climate as warmer temperatures dominate.
As spring transitions into summer, May in National Harbor, United States, brings a welcome dip in humidity to 78%, marking a gradual decline from the wetter months of winter and early spring. This slight decrease in moisture is indicative of the approaching summer season, following the trend observed from earlier months where humidity hovered around the 80% mark. As the weather warms, June sees a minor rise to 79%, but the overall trend suggests that May offers a refreshing respite before the peak heat of summer, making it an ideal time to enjoy outdoor activities in the harbor's scenic beauty. The less humid atmosphere not only enhances comfort but also sets the stage for vibrant blooms and lively waterfront experiences.
As the days warm up in National Harbor, May marks a peak in sun exposure with a UV Index of 10, categorized as very high. This level of UV radiation significantly reduces the time one can safely spend in the sun without protection, bringing the burn time down to just 15 minutes. The trend leading into May shows a steady increase in UV intensity from the moderate levels of January and February, transitioning through high levels in March and April. With summer just around the corner, the UV Index remains elevated, indicating that precautions against sunburn and prolonged exposure are crucial during this time. For more detailed information on UV levels throughout the year, check out the National Harbor UV Index.
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As spring gives way to summer, May shines brightly in National Harbor, boasting an impressive 286 hours of sunshine. This delightful increase in sunshine hours from April reflects the transition into warmer months and sets the stage for outdoor activities and celebrations. The trend continues upward into June and July, where residents can bask in the peak sunshine of 331 and 357 hours, respectively. The gradual rise from January's modest 153 hours to May’s vibrant warmth indicates a community poised to embrace the joy of summer. With a consistent increase in daylight, May serves as the perfect harbinger of the glorious summer days that follow.
In May, the likelihood of sunny weather in National Harbor stands at 40%, a slight dip from April's 49%. This transient sunshine trend is in line with the overall variability observed in the early months of the year. While spring blooms bring fresh optimism, the chances for sun in May are notably lower than in the preceding months like March, which boasts a 52% chance. However, as the seasons transition into summer, it is interesting to note that sunny spells tend to resurge, with June recording a 39% chance. This fluctuating pattern underscores the unpredictable nature of weather, reminding us that while May may start off a bit cloudy, there are still bright moments waiting to emerge.
As the seasons unfold in National Harbor, the May daylight duration heralds the peak of spring, offering 14 hours of sunlight. This marks a delightful increase from the 11 hours in March and is part of a broader trend of escalating daylight as winter’s grip releases its hold. The gradual increase from just 9 hours in January to May’s generous offering exemplifies the awakening of nature, inviting residents and visitors alike to relish longer days filled with outdoor activities. Following May, daylight remains steady at 14 hours through June and July, creating a vibrant backdrop for summer festivities. As the year progresses, a gentle decline in daylight begins, a rhythmic dance of light that characterizes the path from spring to autumn.
In May, the winds in National Harbor, United States, begin to shift slightly as the weather warms. Average wind speeds dip to 2.8 m/s (6 mph), marking a subtle decline from the consistent breezes of the earlier months. This trend suggests a transition to a more tranquil atmosphere, which is typical as summer approaches. Continuing into June, the wind speeds decrease further to 2.5 m/s (6 mph), signaling a general pattern of diminishing winds through the summer months, with July and August exhibiting the lowest averages at 2.3 m/s (5 mph) and 1.9 m/s (4 mph), respectively. However, as fall approaches, September and October witness a slight uptick, returning to 2.5 m/s and 2.7 m/s (6 mph and 6 mph), offering a prelude to the more blustery conditions of late autumn. Overall, May's gentle breezes reflect the serene ambiance of spring, setting the stage for the heat of summer while hinting at the dynamic weather patterns to come.
The weather in National Harbor 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 National Harbor and find detailed weather information for every month.
May and January present stark contrasts in weather conditions. In May, temperatures range from a cool 3°C (37°F) to a warm 35°C (95°F), with an average of 19°C (67°F), while January experiences much colder weather, with temperatures ranging from -14°C (7°F) to 22°C (71°F) and an average of just 3°C (38°F). May also sees higher precipitation at 121 mm (4.8 in) over about 12 days, compared to January’s 61 mm (2.4 in) over only 7 days. Additionally, the humidity in May is slightly lower at 78%, compared to January's 84%. For more details on January's weather, you can visit National Harbor weather in January.
The weather in May is significantly warmer than in February, with temperatures ranging from a chilly minimum of 3°C (37°F) to a warm maximum of 35°C (95°F) and an average of 19°C (67°F). In contrast, February experiences much colder temperatures, with a minimum of -14°C (7°F), an average of 5°C (42°F), and a maximum of 27°C (81°F). While both months see a fair amount of precipitation, May has a higher total of 121 mm (4.8 in) over 12 days compared to February's 96 mm (3.8 in) over 11 days. Humidity levels are also fairly similar, with May at 78% and February slightly higher at 83%. For more detailed insights, you can check National Harbor weather in February.
In comparing the weather of May and March, it's clear that May experiences significantly warmer temperatures, with average highs reaching 19°C (67°F) and maximums soaring up to 35°C (95°F). In contrast, March’s temperatures are much cooler, with averages around 8°C (47°F) and maximums capping at 29°C (84°F). While May sees a higher precipitation total of 121 mm (4.8 in) over about 12 days, March is slightly drier, recording 82 mm (3.2 in) in approximately 9 days. Humidity levels are similar, with May at 78% and March slightly higher at 83%. For more detailed weather information about March, you can visit National Harbor weather in March.
In comparing the weather of May and April, May presents a warmer climate with average temperatures rising to 19°C (67°F), peaking at a high of 35°C (95°F). In contrast, April’s average temperature is cooler at 14°C (58°F), with a maximum of 33°C (92°F). Additionally, May experiences slightly more rainfall, totaling 121 mm (4.8 inches) over 12 days, compared to April's 102 mm (4.0 inches) across 11 days. Humidity levels are also relatively high in both months, with May at 78% and April at 81%. For more details on April weather, you can visit National Harbor weather in April.
In comparing the weather between May and June, we see a noticeable increase in average temperatures. May experiences a minimum temperature of 3°C (37°F) and an average of 19°C (67°F), while June sees a jump to a minimum of 9°C (49°F) and an average of 24°C (76°F). The maximum temperatures also rise, with May reaching up to 35°C (95°F) compared to June's 37°C (98°F). Precipitation is relatively similar, with May recording 121 mm (4.8 in) over 12 days and June slightly less at 107 mm (4.2 in) over 13 days. Humidity levels remain consistent, hovering around 78% in May and 79% in June. For more detailed information about June weather, you can visit National Harbor weather in June.
In comparing the weather patterns of May and July, a stark contrast can be observed. May typically experiences cooler temperatures, with a minimum of 3°C (37°F) and an average of 19°C (67°F), while July boasts significantly warmer conditions, starting from a minimum of 16°C (61°F) and reaching an average of 27°C (81°F). The peak temperatures in July can soar up to 38°C (102°F), compared to May’s maximum of 35°C (95°F). Rainfall is relatively consistent, with May recording 121 mm over 12 days and July experiencing slightly higher precipitation at 132 mm over the same number of days. Additionally, humidity levels are marginally lower in July at 74%, compared to 78% in May. For a more detailed view of July's weather, you can visit National Harbor weather in July.
In comparing the weather between May and August, we see notable differences in temperature and precipitation patterns. May experiences a wider temperature range, with minimums dropping to 3°C (37°F) and maximums reaching up to 35°C (95°F), averaging at 19°C (67°F). In contrast, August boasts a milder minimum of 15°C (59°F) and a higher maximum of 37°C (99°F), with an average temperature of 25°C (78°F). Precipitation is also slightly higher in August at 146 mm (5.7 in) over 15 days compared to May's 121 mm (4.8 in) over 12 days, although the humidity is lower at 72% in August compared to 78% in May. For more detailed information, visit National Harbor weather in August.
In comparing the weather of May and September, May typically experiences a wider temperature range, with minimums as low as 3°C (37°F) and maximums reaching up to 35°C (95°F). In contrast, September sees slightly milder temperatures, with minimums around 6°C (44°F) and maximums peaking at 37°C (99°F), leading to a more consistent average of 22°C (73°F). Precipitation levels in May are noticeably higher, totaling 121 mm (4.8 in) over 12 days, while September has less rainfall at 93 mm (3.7 in) across 11 days. The humidity is somewhat higher in May at 78%, compared to September's 75%. For more detailed information on the climate during this month, you can check National Harbor weather in September.
When comparing the weather in May and October, we find some notable differences and similarities. In May, temperatures range from a minimum of 3°C (37°F) to a maximum of 35°C (95°F), with an average temperature of 19°C (67°F). The month experiences approximately 121 mm (4.8 in) of precipitation over about 12 days, with a humidity level of around 78%. In contrast, October offers slightly cooler conditions, with temperatures ranging from a minimum of 2°C (36°F) to a maximum of 36°C (97°F) and an average temperature of 17°C (63°F). Precipitation is less frequent, totaling around 105 mm (4.2 in) over 9 days, with a slightly higher humidity of 81%. For more detailed insights on how October weather compares in specific locations, you can check National Harbor weather in October.
May and November exhibit contrasting weather patterns, with May generally offering warmer temperatures and higher precipitation. In May, temperatures range from a minimum of 3°C (37°F) to a maximum of 35°C (95°F), with an average of 19°C (67°F) and 121 mm (4.8 in) of rain over 12 days. In contrast, November showcases cooler weather, with temperatures dropping to a minimum of -5°C (23°F) and reaching a maximum of 26°C (78°F), while averaging around 9°C (48°F). November also sees less rainfall, totaling 77 mm (3.0 in) over just 7 days, and slightly higher humidity at 85%. For more details on November weather, check out National Harbor weather in November.
May and December present contrasting weather patterns, highlighting the shift from spring warmth to winter chill. In May, temperatures range from a minimum of 3°C (37°F) to a warm average of 19°C (67°F), peaking at 35°C (95°F). With an average of 121 mm (4.8 in) of precipitation over 12 days, May tends to be humid with a humidity level of 78%. In contrast, December sees much colder conditions, with temperatures ranging from a frigid -10°C (14°F) to a maximum of 20°C (69°F), averaging around 5°C (42°F). The month experiences less precipitation, totaling 89 mm (3.5 in) over 9 days, but with a slight increase in humidity at 84%. For a detailed look at what to expect during December, check out National Harbor weather in December.
As May unfolds in National Harbor, it ushers in a refreshingly mild climate, starkly contrasting the chilly remnants of winter. With temperatures reaching their peak, visitors can bask in the warmth, while the average treads a comfortable balance that invites exploration. Although rainfall may grace the month with its presence on a few days, this adds a refreshing touch, enhancing the lush scenery characteristic of spring. The elevated humidity punctuates the air, reminding us of the impending summer months yet to come. To learn more about what to expect throughout the year, be sure to visit National Harbor Climate.