Last updated: August 21, 2025
September in Hagatna, Guam showcases a tropical climate defined by warm temperatures and high humidity. With maximum temperatures reaching 30°C (86°F) and an average of 28°C (82°F), the island offers a cozy yet humid atmosphere, as the minimum temperature can drop to 25°C (77°F). The month is characterized by significant rainfall, accumulating around 375 mm (14.8 in) over 28 days, creating lush surroundings but also requiring travelers to seek shelter from the showers. This rich tropical setting makes September a unique time to experience the vibrant allure of Guam, despite the persistent humidity hovering around 81%.
In September, Hagatna, Guam, experiences a delightful transition as temperatures peak slightly, with maximums reaching up to 30°C (86°F). The consistent maritime climate keeps minimum temperatures stable at around 25°C (77°F), while the average hovers near a comfortable 28°C (82°F). This month marks a subtle warming trend compared to the previous summer months, where temperatures rarely broke the 29°C (85°F) barrier. As the island remains cocooned in tropical warmth, September presents an inviting atmosphere ideal for beachgoers and adventurers alike, blending sunny days with the soft breezes that characterize Guam's unique charm.
In September, Hagatna, Guam experiences a substantial precipitation amount of 375 mm (14.8 in), highlighting the tail end of the region's wet season. This figure is indicative of a steady trend in rainfall throughout the summer months, particularly after the record-breaking 405 mm (16.0 in) seen in August. Notably, September features an impressive 28 rainy days, allowing for consistent moisture and lush greenery in the surrounding landscape. As the transition to October approaches, precipitation begins to slightly decrease to 356 mm (14.0 in), but the overall trend remains high, emphasizing Guam's tropical climate and its significant rain patterns during this time of year.
In September, Hagatna, Guam experiences a slight dip in humidity, averaging around 81%. This month tends to serve as a bridge between the more humid summer months and the gradual decrease in humidity that follows. Notably, the humidity levels in September mirror those of November, suggesting a seasonal consistency that reflects the tropical climate of the region. Throughout the year, humidity remains relatively high, oscillating between 80% and 84%, but September's reading indicates a subtle shift towards drier conditions as the year transitions into the latter months. As summer fades, residents and visitors can expect a comfortable balance in humidity that complements the warm tropical weather.
In September, Hagatna, Guam, sees a UV Index of 15, categorizing it as extreme and indicating a burn time of just 10 minutes. This month maintains a trend observed throughout the year, where residents and visitors alike must remain vigilant against the strong sun's rays. The UV Index has consistently been high, peaking at 15 in both March and April, with only slight variations as the year progresses. Interestingly, the UV levels tend to decrease gradually from October through December, making September one of the standout months for solar exposure in Hagatna. For more detailed information on UV levels year-round, visit Hagatna UV Index.
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September in Hagatna, Guam, brings a warm embrace of sunshine, although it marks a notable dip in daylight hours compared to the vibrant summer months. With 259 hours of sunshine, September showcases a slight decline from the sun-drenched 336 hours in May. This trend reflects the transition into the latter part of the year, where sunshine gradually wanes from the peak summer days. Despite this decrease, the weather remains inviting, ensuring that outdoor adventures and beach outings can still flourish under the golden sun. As the island gears up for fall, September stands as a reminder of the tropical warmth that characterizes Guam's climate throughout the year.
In Hagatna, Guam, September typically brings a low likelihood of sunny weather, with only a 13% chance of sunshine. This figure is consistent with the notably gloomy conditions of the preceding two months, July and August, which see similar rates of 13% and 5% respectively. Interestingly, this marks a significant drop compared to the sunny spells earlier in the year, where March enjoys the highest sunshine probability at 63%. As the year transitions back toward late fall, the chances of sunshine begin to recover, climbing back up to 50% in November, indicating a clear trend of fluctuating sun availability throughout the year.
In Hagatna, Guam, the daylight duration remains remarkably consistent throughout the year, reflecting the region's tropical climate. As summer gives way to autumn, September maintains the trend with 12 hours of daylight, identical to the preceding months of June, July, and August. This steady illumination provides a vibrant backdrop for the island's lush landscapes and cultural festivities. As daylight hours gradually dip in October to 11 hours, the shift marks the transition towards shorter, cooler days, yet the abundance of sunlight in September offers ample opportunity to soak in the natural beauty and warmth of Guam.
In September, the wind in Hagatna, Guam gently whispers at an average speed of 5.0 m/s (11 mph), maintaining a serene and comfortable atmosphere as the island transitions from summer to fall. This marks a slight dip from the previous month, reflecting a trend of decreasing wind speeds that began in late spring. June and July also saw lower averages, with winds slowing to 4.7 m/s (10 mph) and 5.5 m/s (12 mph), respectively. Interestingly, as the year moves toward its end, wind speeds tend to increase again, showcasing the island's dynamic weather patterns. Overall, September's mild breezes provide a perfect backdrop for enjoying the tropical beauty of Guam.
Weather in Hagatna varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Hagatna, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January exhibit distinct differences in weather patterns. In September, temperatures are generally higher, with a minimum of 25°C (77°F) and an average peak of 30°C (86°F), while January sees slightly lower temperatures, averaging a minimum of 25°C (77°F) and a maximum of 28°C (83°F). Notably, September is much wetter, receiving 375 mm (14.8 in) of precipitation over 28 days, compared to January's 61 mm (2.4 in) across 15 days. Humidity remains relatively stable, with September at 81% and January at 83%. For more detailed weather information, you can check Hagatna weather in January.
September and February exhibit notable differences in weather patterns. September experiences warmer temperatures, with an average of 28°C (82°F) and maximums reaching up to 30°C (86°F), compared to February's slightly cooler average of 27°C (80°F) and a maximum of 28°C (83°F). Additionally, September is much wetter, receiving 375 mm (14.8 in) of precipitation over 28 days, while February is relatively dry, with only 77 mm (3.0 in) of rain spread across 15 days. The humidity levels remain quite similar, with September at 81% and February at 82%. For more details, you can visit Hagatna weather in February.
In September, the weather tends to be warmer, with average temperatures peaking at 28°C (82°F) and a maximum of 30°C (86°F). This month also experiences significantly higher precipitation, with around 375 mm (14.8 in) spread over 28 days, contributing to a humid atmosphere with an average humidity of 81%. In contrast, March brings slightly cooler temperatures, averaging 27°C (81°F) with a maximum of 28°C (83°F). Precipitation drops dramatically to 53 mm (2.1 in) over 15 days, resulting in a somewhat drier and less humid environment, despite the humidity remaining relatively high at 84%. For more details on the weather in March, check out Hagatna weather in March.
September and April showcase distinct weather patterns. In September, the temperature typically ranges from a minimum of 25°C (77°F) to a maximum of 30°C (86°F), with an average of 28°C (82°F). However, this month is characterized by substantial rainfall, accumulating 375 mm (14.8 in) over 28 days, and a humidity level of 81%. In contrast, April experiences slightly cooler temperatures, with a minimum of 25°C (77°F) and a maximum of 29°C (84°F), averaging around 27°C (81°F). Rain in April is significantly reduced, totaling only 94 mm (3.7 in) over 18 days, while humidity remains slightly higher at 84%. For a more detailed outlook on April weather, visit Hagatna weather in April.
In comparing the weather between September and May, we find that both months share similar average temperatures, with minimum temperatures around 25°C (77°F) and average highs of 28°C (82°F). However, September is significantly wetter, receiving 375 mm (14.8 in) of precipitation over 28 days, while May sees a much lower rainfall of 78 mm (3.1 in) over 22 days. Additionally, humidity levels are slightly higher in May at 83%, compared to 81% in September. For more detailed information, you can check Hagatna weather in May.
When comparing the weather in September and June, we see a few notable differences despite their similar average temperatures. September tends to be slightly warmer with a maximum temperature of 30°C (86°F) compared to June's maximum of 29°C (85°F). Additionally, September experiences significantly higher precipitation, totaling 375 mm (14.8 in) across 28 days, whereas June has only 159 mm (6.3 in) over 23 days. The humidity levels remain quite comparable, with September at 81% and June slightly lower at 80%. These factors contribute to a more humid and wetter climate in September. For more detailed information, you can check out Hagatna weather in June.
In comparing the weather of September and July, we see that both months share a similar average temperature, hovering around 28°C (82°F). However, September tends to feature slightly higher maximum temperatures, with a peak of 30°C (86°F) compared to July’s 29°C (85°F). One notable difference is the precipitation levels; September experiences more rain, with 375 mm (14.8 in) over 28 days, while July has a lower total of 276 mm (10.9 in) spread across 30 days. Humidity levels are also similar, with September at 81% and July at 80%. To explore more about July weather, you can check out Hagatna weather in July.
In comparing the weather conditions of September and August, both months exhibit similar temperature ranges, with minimums around 25°C (77°F), average highs of 28°C (82°F), and maximums reaching about 30°C (86°F) in September and 29°C (85°F) in August. However, September experiences slightly less precipitation at 375 mm (14.8 in) compared to August's 405 mm (16.0 in), despite the rainfall being spread over 28 days in September versus 30 days in August. Humidity levels remain consistent, with September at 81% and August at 80%. For a more detailed look at August's weather, visit Hagatna weather in August.
In September, the weather features slightly warmer conditions with a minimum temperature of 25°C (77°F) and an average high of 30°C (86°F). This month is characterized by significant rainfall, accumulating to 375 mm (14.8 in) over 28 days, resulting in a high humidity level of 81%.
In contrast, October maintains a similar temperature range with a minimum of 25°C (78°F) and an average high of 29°C (85°F), but experiences a slight decrease in total precipitation to 356 mm (14.0 in) across 29 days. The humidity is marginally lower at 80%, indicating a slightly drier atmosphere. For more detailed information, check out Hagatna weather in October.
September and November exhibit comparable average temperatures, with both months averaging around 28°C (82°F). However, September tends to be slightly warmer with maximum temperatures reaching up to 30°C (86°F), compared to November's max of 29°C (85°F). A notable difference emerges in precipitation, as September experiences significantly higher rainfall at 375 mm (14.8 in) over 28 days, while November sees reduced precipitation of 202 mm (8.0 in) across 26 days. Humidity levels remain consistent at 81% for both months. For a detailed look at November weather patterns, visit Hagatna weather in November.
September and December weather show notable differences despite their relatively close temperatures. In September, the minimum temperature hovers around 25°C (77°F), with an average of 28°C (82°F) and a peak of 30°C (86°F). This month is characterized by high humidity at 81% and significant rainfall, with 375 mm (14.8 in) of precipitation over 28 days. In contrast, December sees slightly higher minimum temperatures at 26°C (78°F) but lower averages and maximums at 27°C (82°F) and 29°C (84°F), respectively. The humidity increases slightly to 84%, yet the total precipitation drops drastically to 105 mm (4.1 in) over 22 days, indicating a more stable weather pattern. For more detailed information, check Hagatna weather in December.
As September unfolds in Hagatna, expect a delightful blend of warm average temperatures hovering around 28°C (82°F), punctuated by high humidity levels at 81%. Unlike the drier months, this period is characterized by significant precipitation, totaling about 375 mm (14.8 in) over nearly the entire month. The frequent rain showers contribute to the lush, vibrant landscape, making it a unique time in Hagatna's climate calendar. For those eager to learn more about the distinct weather patterns throughout the year, visit Hagatna Climate.