August Weather in Guaynabo, Puerto Rico

Last updated: August 31, 2025

In August, Guaynabo, Puerto Rico experiences a warm and humid tropical climate, with temperatures typically peaking at 31°C (89°F) and averaging around 27°C (81°F). Nighttime brings a slight relief, with minimum temperatures dropping to 23°C (74°F). The month's wet conditions are marked by approximately 130 mm (5.1 in) of rainfall occurring over 25 days, making showers a common occurrence. With humidity levels averaging 80%, the atmosphere feels moist, enhancing the island's lush scenery and vibrant landscapes. Visitors can expect a mix of sun and rain, perfect for experiencing Guaynabo's rich culture and natural beauty.

August Temperature in Guaynabo

In August, Guaynabo, Puerto Rico, experiences a warm and inviting climate, with temperatures reflecting the peak of summer. The month offers a comfortable average temperature of 27°C (81°F), with nighttime lows settling at 23°C (74°F) and daytime highs reaching a steamy 31°C (89°F). This trend of warm weather is consistent with the preceding months of June and July, where temperatures remain relatively stable. As August progresses, the tropical humidity enhances the heat, inviting both residents and visitors to bask in the sun or seek relief in the refreshing Caribbean waters. Overall, August in Guaynabo encapsulates the essence of summer, combining warmth with the vibrant energy of the island.

August Weather in Guaynabo: Daily Temperature Highs, Lows, and Averages

The chart illustrates August temperature patterns in Guaynabo, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Guaynabo, August typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec757575777980818181807877
Data source: Temperature data for Guaynabo 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.

August Precipitation in Guaynabo

In August, Guaynabo, Puerto Rico, experiences a noticeable spike in precipitation, with an average of 130 mm (5.1 in) recorded over 25 days of rain. This trend marks a continuation of the wet season, following July's already significant rainfall of 124 mm (4.9 in). As the summer transitions into fall, precipitation peaks as August stands out for its frequent rainfall, setting the stage for the even wetter months ahead. Interestingly, the increase in precipitation is reflective of a broader pattern, with September typically bringing even higher totals, reaching an impressive 200 mm (7.9 in). This steady rise in both the amount of rainfall and the number of rainy days underscores the tropical climate's influence on the region, making water management a vital focus for residents and visitors alike.

August Precipitation Trends in Guaynabo

The chart displays monthly precipitation patterns in Guaynabo, with values for each month alongside August’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how August’s conditions compare to those of other months. In Guaynabo, August typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec485380779810012413020018312066
Data source: Precipitation data for August generated using information from the Copernicus Climate Change Service.
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August Humidity in Guaynabo

In August, Guaynabo, Puerto Rico experiences a peak in humidity, stabilizing at around 80%, a continuation of the upward trend from the previous months. As the summer progresses, the humidity consistently rises from 76% in January to this summer high, reflecting the tropical climate's influence. Following a brief dip in September to 79%, the humidity gradually decreases towards the end of the year but remains notably high, hovering around 78% in the cooler months. This pattern underscores a humid subtropical environment where summer brings increased moisture, creating a distinctive weather experience that defines Guaynabo's climate.

August Average Humidity in Guaynabo

This chart illustrates the average monthly humidity levels in Guaynabo, with August’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In August, average humidity in Guaynabo is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%75%74%75%75%77%80%80%79%78%78%76%
Data source: Humidity data for August generated using information from the Copernicus Climate Change Service.

August UV Index in Guaynabo

In Guaynabo, Puerto Rico, the UV Index remains consistently high throughout the summer months, reflecting a strong trend of extreme sun exposure. As August rolls in, the UV Index reaches an impressive 13, categorizing it as extreme, with a burn time of just 10 minutes. This pattern of elevated UV levels begins as early as January, peaking in May with an Index of 14, before gradually stabilizing around 13 from August through September. Though the intensity diminishes slightly in October, the first part of the year showcases significant risks, urging residents and visitors alike to protect their skin vigorously. To stay informed and safe under the blazing sun, check out more details at Guaynabo UV Index.

Maximum UV Index Levels in Guaynabo for August

The chart shows the monthly maximum UV Index (UVI) for Guaynabo in August, 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. In August, the maximum UV index in Guaynabo typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec911131314131213131298
Data source: Guaynabo August 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.

August Sunshine in Guaynabo

In Guaynabo, Puerto Rico, August shines brightly with an impressive 349 hours of sunshine, marking one of the sunniest months of the year. This trend of abundant sunshine begins in the spring and continues through the summer, peaking in May with 356 hours, before maintaining a warm glow into August. The sun starts to wane slightly in September, yet still offers a generous 313 hours. Overall, the gradual decline in sunshine hours after August suggests a transition towards the cooler months, but the summer glow lingers, making Guaynabo a radiant destination during these vibrant sunny days.

Monthly Sunshine Duration in Guaynabo: August Highlighted

The August sunshine duration represents the total number of hours Guaynabo experiences direct sunlight during the month of August, excluding cloudy or obstructed periods. This chart compares the sunshine duration of August with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec257h303h346h346h356h343h353h349h313h313h299h319h
Data source: Guaynabo August Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Guaynabo During August

In Guaynabo, Puerto Rico, the likelihood of sunny weather in August takes a dip, with only a 37% chance of sunshine, marking it as one of the less luminous months of the year. This trend follows the typical pattern observed during the summer months, where chances of sun decline significantly—dipping as low as 20% in June and 38% in July. Interestingly, while the spring months boast healthier prospects, peaking at 65% in February, the shift toward late summer suggests a transition into wetter conditions, typical of the island's tropical climate. As September rolls in, the chance of sun slightly rebounds to 44%, indicating a gradual return of brighter days as the season changes.

Percentage of Sunny Days in August in Guaynabo

The chart illustrates the percentage of sunny days in Guaynabo throughout the year, with August 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 Guaynabo experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec48%66%60%43%50%20%39%37%44%44%55%58%
Data source: Guaynabo August chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Guaynabo in August

In Guaynabo, Puerto Rico, the trend in daylight duration reveals a fascinating rhythm throughout the year. As the year begins, daylight stretches to 11 hours in both January and February, hinting at the shorter winter days. The arrival of March marks a subtle increase to 12 hours, a change that persists through April and May as spring unfolds. The daylight reaches its peak in June and July with a generous 13 hours, celebrating the height of summer. However, come August, there’s a slight retreat as daylight returns to 12 hours, similar to earlier spring months, before tapering off again to 11 hours from October to December. This cyclical pattern showcases Guaynabo's consistent climate, where daylight duration varies elegantly around the equatorial axis.

Average Daylight Hours in Guaynabo for August

The chart illustrates the variation in daylight duration in Guaynabo throughout the year, with August highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 9m11h 32m12h 2m12h 33m12h 59m13h 11m13h 4m12h 42m12h 12m11h 42m11h 15m11h 2m
Data source: Guaynabo daylight hours, calculated by summing the hours between sunrise and sunset for each day.

August Winds in Guaynabo

In August, Guaynabo, Puerto Rico experiences a refreshing average wind speed of 3.5 m/s (8 mph), maintaining a gentle breeze that slightly lags behind the windier months of July and February, both peaking at 4.0 m/s (9 mph). As summer transitions towards fall, the winds tend to soften, dropping to their annual low of 2.4 m/s in September. However, August's winds provide a delightful reprieve from the tropical heat, fostering an inviting atmosphere ideal for outdoor activities. Overall, the month showcases a trend of moderate winds, hinting at the shifting seasons while still embracing the island's vibrant summer spirit.

Average August Wind Speed in Guaynabo

The chart displays monthly wind speed patterns in Guaynabo, with values for each month shown alongside August's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how August's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec3.14.03.42.93.43.74.03.5 m/s2.42.62.73.3
Data source: Guaynabo August wind data, generated using information from the Copernicus Climate Change Service.

How August Weather in Guaynabo Compares to Other Months

Weather in Guaynabo varies notably across the year, with each month offering distinct climate conditions. This page compares August’s weather to other months in Guaynabo, focusing on differences in temperature, rainfall, humidity, and UV levels.

In August, the weather is notably warmer and more humid compared to January, with average temperatures hovering around 27°C (81°F) and a maximum of 31°C (89°F). The month sees significant rainfall, averaging 130 mm (5.1 in) over 25 days. In contrast, January experiences milder temperatures, with an average of 24°C (76°F) and a maximum of 29°C (84°F). Precipitation is substantially lower in January, totaling 48 mm (1.9 in) across 16 days, accompanied by slightly lower humidity at 76%. For more detailed information on the weather, you can visit Guaynabo weather in January.

Comparing the weather in August and February reveals some notable differences. August tends to be warmer, with temperatures ranging from a minimum of 23°C (74°F) to a maximum of 31°C (89°F) and an average of 27°C (81°F). In contrast, February is slightly cooler, with temperatures ranging from 20°C (69°F) to 28°C (83°F) and an average of 24°C (75°F). Additionally, August sees higher precipitation levels, totaling 130 mm (5.1 in) over 25 days, while February experiences significantly less rain at 53 mm (2.1 in) across 18 days. The humidity is also slightly higher in August at 80%, compared to 75% in February. For a detailed look at February weather, visit Guaynabo weather in February.

When comparing the weather in August and March, August tends to be warmer and more humid. In August, temperatures range from a minimum of 23°C (74°F) to a maximum of 31°C (89°F), with an average of 27°C (81°F). In contrast, March features slightly cooler temperatures, with a minimum of 20°C (69°F) and a maximum of 29°C (85°F), averaging 24°C (76°F). Precipitation is also more substantial in August, totaling 130 mm (5.1 in) over 25 rainy days, compared to March's 80 mm (3.2 in) spread across 21 days. Additionally, the humidity in August is notably higher at 80% versus March's 74%. For more information on March weather specifics, you can visit Guaynabo weather in March.

When comparing the weather in August and April, one can observe notable differences in temperature and precipitation patterns. August tends to be hotter, with average temperatures reaching up to 27°C (81°F) and maximums soaring to 31°C (89°F). In contrast, April has a slightly cooler average temperature of 25°C (77°F) and a maximum of 30°C (86°F). Precipitation is also more significant in August, with 130 mm (5.1 in) spread over 25 days, compared to 77 mm (3.0 in) over 20 days in April. Moreover, humidity levels are higher in August at 80%, while April experiences a more comfortable 75%. For a more detailed look at April's weather, visit Guaynabo weather in April.

In comparing the weather between August and May, we find that both months experience warm temperatures, but August tends to be slightly hotter on average, with temperatures ranging from a minimum of 23°C (74°F) to a maximum of 31°C (89°F). In contrast, May offers a similar temperature range but slightly cooler, with averages of 22°C (72°F) to 31°C (87°F). However, August sees more precipitation, with 130 mm (5.1 in) over 25 days compared to May's 98 mm (3.9 in) across 24 days, resulting in higher humidity levels of 80% in August versus 75% in May. For a detailed look at the weather patterns in May, you can visit Guaynabo weather in May.

In comparing the weather between June and August, both months exhibit similar temperature patterns, with minimums around 23°C (74°F), averages near 27°C (81°F), and maximums peaking at 31°C (89°F) for August and slightly lower at 31°C (88°F) for June. However, August tends to be wetter, with a total precipitation of 130 mm (5.1 in) across 25 days, compared to June's 99 mm (3.9 in) over 23 days. Additionally, humidity levels are slightly higher in August at 80%, versus June’s 77%. For a detailed look at June's weather, you can check Guaynabo weather in June.

When comparing the weather conditions in August and July, we find several similarities and slight variations. Both months have the same minimum temperature of 23°C (74°F) and average temperature of 27°C (81°F). However, August experiences a marginally higher maximum temperature at 31°C (89°F) compared to July's 31°C (88°F). In terms of precipitation, August has 130 mm (5.1 in) over 25 days, which is slightly more than July's 124 mm (4.9 in) over 24 days. Despite these minor differences, both months maintain a high humidity level of 80%. For a more detailed look at July's weather, you can check out Guaynabo weather in July.

In August, the weather is characterized by a minimum temperature of 23°C (74°F) and an average of 27°C (81°F), peaking at a maximum of 31°C (89°F), accompanied by substantial rainfall totaling 130 mm (5.1 in) over 25 days, and a humidity level of 80%. In contrast, September maintains a similar temperature range with a minimum of 23°C (74°F) and an average of 27°C (81°F), but it reaches a slightly higher maximum of 32°C (90°F). September is notably wetter, with precipitation increasing to 200 mm (7.9 in) over 27 days, and humidity remains relatively stable at 79%. For more detailed information, check out Guaynabo weather in September.

In comparing the weather between August and October, we notice some intriguing similarities and differences. Both months share the same minimum (23°C or 74°F), average (27°C or 81°F), and maximum temperatures (31°C or 89°F for August and 88°F for October), indicating a consistent warm climate. However, October experiences slightly more rainfall with 183 mm (7.2 in) spread over 27 days, compared to August's 130 mm (5.1 in) over 25 days. The humidity remains high in both months, but October's 78% is a tad lower than August's 80%. For more detailed insights, you can check Guaynabo weather in October.

The weather in August tends to be warmer and more humid compared to November, with average temperatures ranging from a minimum of 23°C (74°F) to a maximum of 31°C (89°F). In contrast, November sees slightly cooler temperatures, with averages between 22°C (72°F) and 30°C (86°F). August also experiences higher precipitation, totaling 130 mm (5.1 in) over 25 days, while November has 120 mm (4.7 in) of rainfall over 23 days. Humidity in August stands at 80%, making it feel even hotter, while November's humidity is a bit lower at 78%. For a closer look at the weather specifics in November, you can visit Guaynabo weather in November.

In comparing the weather between August and December, we notice distinct differences in temperature and precipitation. August typically features warmer conditions, with average temperatures reaching 27°C (81°F) and highs of 31°C (89°F), while December is slightly cooler, averaging 25°C (77°F) with a maximum of 30°C (86°F). Humidity levels remain high in both months, but August (80%) is slightly more humid than December (76%). Additionally, August experiences significantly more rainfall, with 130 mm (5.1 in) spread over 25 days, compared to December's 66 mm (2.6 in) over 22 days. For a detailed look at the December climate, you can visit Guaynabo weather in December.

Compare Guaynabo's Climate with Cities Worldwide

Conclusion: What to Expect From August Weather in Guaynabo

As August unfolds in Guaynabo, the weather showcases distinct characteristics that set it apart from other months. With daily temperatures peaking around 31°C (89°F), the heat is palpable, contrasting with the milder climates of earlier months. This month is also notably humid, with humidity levels averaging around 80%, creating a tropical feel that can be intense. The rainfall is significant, with August experiencing frequent showers on about 25 days, accumulating around 130 mm (5.1 in) of precipitation. These conditions are indicative of the transition towards the wetter season, making August a unique blend of warmth and moisture. For those interested in understanding more about Guaynabo's climate, be sure to check out Guaynabo Climate.