July Weather in National Harbor, United States

Last updated: February 24, 2025

July in National Harbor, United States showcases summer at its peak, with temperatures soaring to a maximum of 38°C (102°F) and an average of 27°C (81°F), while dipping to a pleasant minimum of 16°C (61°F) at night. Travelers can expect a humid environment, with 74% humidity contributing to the warm atmosphere. Despite the heat, this month also sees 132 mm (5.2 in) of rainfall spread across 12 days, offering a refreshing interlude amidst the sun-soaked days. Whether basking in the warmth or seeking shade during the rain, July promises a vibrant mix of summer experiences in National Harbor.

July Temperature in National Harbor

In July, National Harbor experiences its warmest temperatures of the year, showcasing a striking climate shift that peaks at a max of 38°C (102°F). With a comfortable min of 16°C (61°F) and an average temperature of 27°C (81°F), July invites outdoor enthusiasts to bask in summer activities. This month stands in stark contrast to the colder depths of winter; notably, January's frigid min of -14°C (7°F) highlights the dramatic seasonal transition. The trend of rising temperatures continues from the prior month, June, which wraps up with an impressive max of 37°C (98°F), signaling a continual climb towards midsummer. As the heat settles in, both locals and tourists flock to the scenic waterfront, making the most of the vibrant summer ambience.

July Weather in National Harbor: Daily Temperature Highs, Lows, and Averages

The chart illustrates July temperature patterns in National Harbor, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec374247576776817872634841
Data source: Temperature data for National Harbor 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.

July Precipitation in National Harbor

In July, National Harbor experiences one of its wettest months, receiving an average of 132 mm (5.2 inches) of rainfall over about 12 days. This spike in precipitation is a noticeable trend as summer reaches its peak, often bringing afternoon thunderstorms that contribute to the overall totals. Compared to the preceding months, July's rainfall marks a significant increase from June's 107 mm (4.2 inches), highlighting a shift towards the wetter conditions typical of late summer. Following closely is August, which continues this pattern with an even higher average of 146 mm (5.7 inches), indicating a transitional climate as the region navigates the vibrant, stormy heart of the season.

July Precipitation Trends in National Harbor

The chart displays monthly precipitation patterns in National Harbor, with values for each month alongside July's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how July's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec619682102121108132146931057789
Data source: Precipitation data for July generated using information from the Copernicus Climate Change Service.
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July Humidity in National Harbor

In July, National Harbor experiences a noticeable dip in humidity, with levels averaging 74%. This decline from the warmer months reflects a broader trend as the summer progresses; after peaking earlier in the season, humidity levels gradually decrease, hitting their lowest point in mid-summer. Following July, August continues this trend with even lower humidity at 72%, suggesting a shift toward drier conditions. If we look at the year as a whole, it's clear that the winter months bring higher humidity levels, starting at 84% in January and settling at 85% in November. This cyclical pattern highlights the transition from moist winter air to the relatively drier atmosphere of summer, offering a comfortable reprieve for residents and visitors alike during the peak of summer heat.

July Average Humidity in National Harbor

This chart illustrates the average monthly humidity levels in National Harbor, with July's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how July's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec84%83%83%81%78%79%74%72%75%81%85%84%
Data source: Humidity data for July generated using information from the Copernicus Climate Change Service.

July UV Index in National Harbor

In July, the UV Index in National Harbor, United States, remains at a peak of 10, categorizing exposure as very high with a burn time of just 15 minutes. This trend of elevated UV levels began in April, reaching its apex with consistent ratings of 10 in both June and July. As summer reaches its zenith, sun protection becomes crucial, as the potential for skin damage intensifies. Following July, the UV Index will dip slightly in August and September, transitioning back to high levels in the fall. For more detailed information, visit the National Harbor UV Index.

Maximum UV Index Levels in National Harbor for July

The chart shows the monthly maximum UV Index (UVI) for National Harbor in July, 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.
JanFebMarAprMayJunJulAugSepOctNovDec357910101098753
Data source: National Harbor July 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.

July Sunshine in National Harbor

July shines brightly in National Harbor, boasting an impressive 357 hours of sunshine, the pinnacle of the year's sun-filled days. This peak comes on the heels of a steady increase that begins in the new year, with January starting at a modest 153 hours. As the seasons progress, the hours of sunlight rise gradually each month, with June already providing a generous 331 hours. July's abundant sunshine not only enhances the warmth of summer but also sets the stage for the vibrant outdoor activities that characterize this lively destination. Following July, the sunlight begins to wane, slipping to 321 hours in August, illustrating a natural ebb as summer transitions to fall. This pattern of rising and falling hours reflects the typical seasonal shift in National Harbor, with July standing out as a golden gem of summertime brightness.

Monthly Sunshine Duration in National Harbor: July Highlighted

The July sunshine duration represents the total number of hours National Harbor experiences direct sunlight during the month of July, excluding cloudy or obstructed periods. This chart compares the sunshine duration of July with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec153h180h259h259h286h331h357h321h276h249h226h190h
Data source: National Harbor July Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in National Harbor During July

In National Harbor, July offers a 49% chance of sunny weather, making it one of the more favorable months for enjoying the outdoors. This aligns closely with the preceding months, where the likelihood of sunshine fluctuates, particularly peaking in September at 55%. Interestingly, while July’s sunshine probability matches April and is higher than the summer months of August and June, it does not quite reach the levels of November’s 58%. As a result, visitors can anticipate relatively bright days with a blend of summer warmth, making it a delightful time to explore the scenic waterfront and partake in outdoor activities.

Percentage of Sunny Days in July in National Harbor

The chart illustrates the percentage of sunny days in National Harbor throughout the year, with July 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 National Harbor experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec46%29%52%49%40%39%49%35%55%41%58%39%
Data source: National Harbor July chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in National Harbor in July

In National Harbor, United States, July boasts a generous 14 hours of daylight, maintaining the same amount found in June. This peak in daylight hours not only illuminates the warm summer days but also invites outdoor adventures and vibrant activities. Following July, as summer wanes, daylight begins to gradually decrease, dropping to 13 hours in August and continuing a subtle decline into the fall months. The trend reveals a seasonal rhythm where longer days herald the summer's warmth, transitioning into the shorter, cozier days of autumn. As the year progresses, daylight durations ebb and flow, reflecting the natural cycle of the seasons, and offering a dynamic backdrop to life in National Harbor.

Average Daylight Hours in National Harbor for July

The chart illustrates the variation in daylight duration in National Harbor throughout the year, with July highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 47m10h 45m11h 58m13h 14m14h 18m14h 49m14h 32m13h 35m12h 23m11h 8m10h 2m9h 29m
Data source: National Harbor daylight hours, calculated by summing the hours between sunrise and sunset for each day.

July Winds in National Harbor

In July, the winds in National Harbor experience a notable shift, with an average speed of 2.3 m/s (5 mph), making it the lightest month of the year for breezes. This decline follows a gradual decrease from the spring months, where winds were consistently stronger at around 3.2 m/s (7 mph). As the summer unfolds, the winds trend further down into August, reaching an average of 1.9 m/s (4 mph). This pattern indicates a calming environment, perfect for leisurely activities by the water, yet it contrasts with the fresher breezes felt in the earlier months. Such fluctuations not only reflect the seasonal changes but also enhance the region's inviting charm during the warmer months.

Average July Wind Speed in National Harbor

The chart displays monthly wind speed patterns in National Harbor, with values for each month shown alongside July's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how July's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec2.93.23.23.22.82.52.3 m/s1.92.52.72.92.8
Data source: National Harbor July wind data, generated using information from the Copernicus Climate Change Service.

How July Weather in National Harbor Compares to Other Months

The weather in National Harbor changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of July'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.

When comparing the weather in July and January, a stark contrast emerges. July typically boasts a warm climate with average temperatures around 27°C (81°F) and highs reaching up to 38°C (102°F), accompanied by higher humidity levels at 74%. In contrast, January experiences much colder temperatures, with averages around 3°C (38°F) and lows dipping to -14°C (7°F). January also sees less precipitation, with about 61 mm (2.4 in) over fewer days, making it a drier month overall compared to July's 132 mm (5.2 in) spread over 12 days. For more detailed insights, check National Harbor weather in January.

July and February present a stark contrast in weather patterns. In July, temperatures range from a minimum of 16°C (61°F) to a maximum of 38°C (102°F), with an average of 27°C (81°F), making it the warmest month. This summer heat is accompanied by significant humidity levels at 74% and 132 mm (5.2 in) of precipitation over 12 days. In sharp contrast, February typically experiences much colder conditions, with temperatures fluctuating from a chilling -14°C (7°F) to a maximum of 27°C (81°F), averaging only 5°C (42°F). Despite having slightly lower total precipitation at 96 mm (3.8 in) over 11 days, February's higher humidity of 83% adds to the crispness of the winter air. For more detailed insights, you can check out National Harbor weather in February.

In comparing the weather between July and March, it's evident that July is significantly warmer and more humid. While July boasts average temperatures around 27°C (81°F) and can reach highs of 38°C (102°F), March experiences much cooler conditions with averages of only 8°C (47°F) and a maximum of 29°C (84°F). Additionally, July sees more precipitation, totaling 132 mm (5.2 in) over 12 days, compared to March's 82 mm (3.2 in) over 9 days. Interestingly, while March is cooler, it has a higher humidity level at 83%, compared to July's 74%. For more insights on the weather in March, you can visit National Harbor weather in March.

When comparing the weather in July and April, there are notable differences in temperature and precipitation patterns. July tends to be significantly warmer, with average temperatures hovering around 27°C (81°F) and maximums reaching as high as 38°C (102°F). In contrast, April experiences much cooler conditions, with averages around 14°C (58°F) and maximums of 33°C (92°F). Both months see considerable precipitation, but July has a slightly higher total of 132 mm (5.2 in) compared to April's 102 mm (4.0 in), and both months experience similar numbers of rainy days—12 in July and 11 in April. Additionally, while July has a humidity level of 74%, April is slightly more humid at 81%. For more details, you can check National Harbor weather in April.

In comparing the weather of July and May, July tends to be much warmer, with average temperatures reaching 27°C (81°F) compared to May's average of 19°C (67°F). July also experiences higher maximum temperatures, soaring up to 38°C (102°F), whereas May's peak reaches a comfortable 35°C (95°F). Both months see a similar amount of precipitation, with July receiving 132 mm (5.2 in) and May closely following at 121 mm (4.8 in), both experiencing rainfall over 12 days. Interestingly, humidity levels are slightly lower in July at 74%, while May maintains a higher humidity of 78%. For a closer look at how May weather unfolds, check out National Harbor weather in May.

In comparing the weather between June and July, July typically offers warmer temperatures, with a minimum of 16°C (61°F) and an average high of 27°C (81°F), while June starts off cooler with a minimum of 9°C (49°F) and an average temperature of 24°C (76°F). Although July reaches a maximum of 38°C (102°F), it also experiences slightly higher precipitation, totaling 132 mm (5.2 in) over 12 days, compared to June's 107 mm (4.2 in) across 13 days. Furthermore, humidity levels are slightly lower in July at 74%, compared to June's 79%. For a detailed look at the weather in June, check out National Harbor weather in June.

In comparing the weather of July and August, July tends to be slightly warmer with average temperatures reaching 27°C (81°F) and maximums hitting 38°C (102°F). In contrast, August has a cooler average temperature of 25°C (78°F) and a maximum of 37°C (99°F). Precipitation is also a notable factor; July receives 132 mm (5.2 inches) over 12 days, while August sees increased rainfall of 146 mm (5.7 inches) across 15 days. Additionally, humidity is marginally lower in August at 72% compared to July's 74%. For more detailed weather information, check out National Harbor weather in August.

July and September present distinctly different weather patterns. In July, temperatures can soar with daytime highs averaging around 27°C (81°F) and peaking at 38°C (102°F), while nighttime lows rarely drop below 16°C (61°F). This month also sees a substantial amount of precipitation, totaling 132 mm (5.2 in) over approximately 12 days, contributing to a high humidity level of 74%. In contrast, September experiences cooler temperatures, with an average of 22°C (73°F), minimums dropping to 6°C (44°F), and maximums reaching 37°C (99°F). The month sees less rainfall, with a total of 93 mm (3.7 in) over 11 days and slightly higher humidity at 75%. For more detailed insights into September weather, visit National Harbor weather in September.

In July, the weather typically features much warmer temperatures, with a minimum of 16°C (61°F) and an average high reaching 38°C (102°F), accompanied by significant humidity at 74%. The month sees around 132 mm (5.2 in) of precipitation spread over 12 days, making for a relatively wet summer. In contrast, October experiences considerably cooler temperatures, with a minimum of 2°C (36°F) and an average of 17°C (63°F), though it can still reach a maximum of 36°C (97°F) on warmer days. October has less rainfall, with 105 mm (4.2 in) over just 9 days, but the humidity increases to 81%. For those interested in more details, you can check out National Harbor weather in October.

July and November offer stark contrasts in weather. July enjoys warm temperatures with a minimum of 16°C (61°F) and an average of 27°C (81°F), peaking at a sweltering 38°C (102°F). Additionally, it experiences a significant amount of rainfall, totaling 132 mm (5.2 in) over about 12 days, with humidity levels at a high 74%. In contrast, November brings much cooler conditions, with temperatures ranging from a minimum of -5°C (23°F) to an average of 9°C (48°F), reaching a maximum of 26°C (78°F). The month sees less precipitation, totaling 77 mm (3.0 in) over 7 days, yet it has higher humidity at 85%. For a more detailed look at November weather, check out National Harbor weather in November.

In July, temperatures are significantly warmer, with a minimum of 16°C (61°F) and an average of 27°C (81°F), reaching highs of up to 38°C (102°F). The month experiences substantial rainfall, totaling 132 mm (5.2 in) over approximately 12 days, coupled with a humidity level of 74%.

In contrast, December brings much cooler weather, with temperatures dropping to a minimum of -10°C (14°F) and an average of just 5°C (42°F), reaching a maximum of 20°C (69°F). Although precipitation is lower at 89 mm (3.5 in) over 9 days, humidity is slightly higher at 84%. For more details on the specific weather conditions during this month, you can visit National Harbor weather in December.

Compare National Harbor's Climate with Cities Worldwide

Conclusion: What to Expect From July Weather in National Harbor

In July, National Harbor experiences a distinct transformation in its weather, marked by higher temperatures and increased humidity compared to other months. With average highs reaching a sizzling 38°C (102°F) and nights cooling down pleasantly to 16°C (61°F), visitors can enjoy vibrant summer days and warm evenings. However, this warmth comes with increased precipitation, as July sees about 12 days of rain, contributing to a humidity level that hovers around 74%. These factors together create a lush and lively atmosphere, perfect for summer adventures. For a deeper look at how July stands out from the rest of the year, explore National Harbor Climate.