September Weather in Roseau, Dominica

Last updated: August 21, 2025

In September, Roseau, Dominica experiences warm temperatures and a tropical ambiance, with maximums reaching 29°C (84°F) and an average of 27°C (81°F). The evenings offer a mild respite, with minimum temperatures around 25°C (78°F). However, this month is characterized by significant rainfall, totaling 114 mm (4.5 in), spread over 17 days, contributing to a high humidity level of 80%. Travelers can expect a lush, vibrant landscape shaped by this seasonal precipitation, perfect for exploring the island's natural beauty amidst warm, tropical conditions.

September Temperature in Roseau

In September, Roseau, Dominica, experiences pleasantly warm temperatures, marking a consistent transition into the tail end of the summer season. With minimum temperatures around 25°C (78°F) and maximums reaching 29°C (84°F), the month maintains an average of 27°C (81°F)—a slight increase from August. This warmth sets a tropical backdrop, perfect for exploring the lush landscapes and vibrant culture that Dominica has to offer. As the temperatures hover steady, it's clear that September continues the trend of balmy weather, inviting visitors to soak in the sun-drenched beauty of the island before the cooler months approach.

September Weather in Roseau: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Roseau, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Roseau, September 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).
JanFebMarAprMayJunJulAugSepOctNovDec777777787980808181818079
Data source: Temperature data for Roseau 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.

September Precipitation in Roseau

September marks a notable peak in precipitation in Roseau, Dominica, where the monthly rainfall reaches 114 mm (4.5 in), further intensifying from the previous month. With 17 days of rain, September holds a significant place in the annual cycle, showcasing a transition into the wet season. This trend clearly indicates that as summer wanes, the Island not only experiences an uptick in rainfall but also prepares for the following months, which continue to see elevated precipitation levels, peaking in October. Thus, September serves as a crucial bridge, linking the heavier rains of late summer with the upcoming months, enhancing the vibrant, lush landscape that Dominica is known for.

September Precipitation Trends in Roseau

The chart displays monthly precipitation patterns in Roseau, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Roseau, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec363634323568971101141179753
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Roseau

In September, the humidity in Roseau, Dominica, reaches 80%, continuing the trend of high moisture levels characteristic of the island. Following the peak of 84% in July, there’s a slight dip, but the humidity remains notably elevated, reflecting the tropical climate. This month, along with May and October, ranks among the more humid periods, marking a transition as the rainy season begins to soften its grip. Overall, the consistent humidity, which hovers around the 80% mark during these late summer months, plays a vital role in shaping the lush landscapes and vibrant ecosystems that Dominica is renowned for.

September Average Humidity in Roseau

This chart illustrates the average monthly humidity levels in Roseau, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Roseau is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec78%77%78%78%80%82%84%82%80%80%80%79%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Roseau

September in Roseau, Dominica, continues the trend of extremely high UV exposure, maintaining a UV Index of 13. This index places it alongside the peak summer months, where the burn time remains notably brief at just 10 minutes. Such intensity underscores the need for sun protection as residents and visitors alike enjoy the tropical climate. As we transition into the fall, this extreme UV exposure mirrors the patterns observed from late spring through August, indicating that caution is crucial during this time. For more detailed information on UV levels throughout the year, visit Roseau UV Index.

Maximum UV Index Levels in Roseau for September

The chart shows the monthly maximum UV Index (UVI) for Roseau in September, 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 September, the maximum UV index in Roseau typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec10111314141314131312109
Data source: Roseau September 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.

September Sunshine in Roseau

As September unfolds in Roseau, Dominica, the island basks in a delightful 319 hours of sunshine, a blend of warm, golden days that precede the gentle transition into autumn. This month typically maintains a generous share of sunlight, slightly lower than the peak in May but still abundant compared to the earlier months of the year. Following the lively summer months of July and August, which recorded 354 and 347 hours respectively, September showcases a steady trend of sun-soaked days that linger longer as the year draws to a close. With an average of over 300 hours of sunshine throughout the months, Roseau continues to charm visitors and locals alike, inviting outdoor adventures and tranquil moments under the sun's warm embrace.

Monthly Sunshine Duration in Roseau: September Highlighted

The September sunshine duration represents the total number of hours Roseau experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec267h305h347h339h357h328h354h347h319h320h311h329h
Data source: Roseau September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Roseau During September

In September, Roseau, Dominica, enjoys a 59% chance of sunny weather, making it a delightful choice for sun-seekers who want to experience the lush scenery of the island. As the rainy season approaches its peak in late summer, the likelihood of clear skies actually rises slightly from the previous months of July and August, which recorded 54% and 49% respectively. This trend suggests that early September can still provide plenty of opportunities to soak up the sun before the heavier rains of autumn set in. With a relatively high chance of sunshine compared to surrounding months, September presents a unique window to explore the natural beauty and vibrant culture of Dominica.

Percentage of Sunny Days in September in Roseau

The chart illustrates the percentage of sunny days in Roseau throughout the year, with September 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 Roseau experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec56%73%51%44%52%31%54%49%59%52%66%67%
Data source: Roseau September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Roseau in September

In September, Roseau, Dominica enjoys a delightful 12 hours of daylight, maintaining the steady rhythm established during the preceding months of July and August. This consistency is a hallmark of the island’s tropical climate, where daylight duration generally hovers around 11 to 13 hours throughout the year. As the year transitions from summer into autumn, daylight slowly wanes, with October signaling a slight decrease to 11 hours. The overall trend reflects a harmonious balance of light and darkness, making Roseau a paradise for outdoor enthusiasts and sun-seekers alike.

Average Daylight Hours in Roseau for September

The chart illustrates the variation in daylight duration in Roseau throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 19m11h 38m12h 2m12h 28m12h 50m13h12h 55m12h 36m12h 11m11h 45m11h 23m11h 13m
Data source: Roseau daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Roseau

As September rolls in, the winds in Roseau, Dominica, begin to soften, with an average speed of 5.3 m/s (12 mph), making it the calmest month of the year. Following a summer of more bracing breezes, where speeds reached up to 9.7 m/s (22 mph) in February, September's gentle airflow invites a tranquil atmosphere ideal for relaxation. This month typically experiences a noticeable dip compared to the summer months, marked by a steady decrease from July's 8.7 m/s (19 mph) and August's 7.1 m/s (16 mph). As the hurricane season lingers, the prevailing softness of September's winds offers a reminder of the island's serene beauty, encouraging locals and visitors alike to savor the peaceful moments before autumn settles in.

Average September Wind Speed in Roseau

The chart displays monthly wind speed patterns in Roseau, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec8.29.78.27.08.28.68.77.15.3 m/s7.36.68.4
Data source: Roseau September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Roseau Compares to Other Months

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

In September, the weather is generally warmer and wetter, with temperatures ranging from a minimum of 25°C (78°F) to a maximum of 29°C (84°F) and an average of 27°C (81°F). The month sees significant rainfall, totaling 114 mm (4.5 inches) over 17 days, contributing to the high humidity of 80%. In contrast, January experiences slightly cooler temperatures, with a range from 23°C (73°F) to 27°C (80°F) and an average of 25°C (78°F). Precipitation is much lower, at 36 mm (1.4 inches) over 13 days, and humidity is slightly reduced at 78%. For a more detailed look at January's weather patterns, you can visit Roseau weather in January.

In September, the weather tends to be warmer and more humid, with temperatures averaging around 27°C (81°F) and reaching a maximum of 29°C (84°F). The month also experiences significant rainfall, with a total of 114 mm (4.5 in) over 17 days, resulting in a humidity level of 80%. In contrast, February brings milder temperatures, with an average of 25°C (77°F) and a maximum of 26°C (80°F). Additionally, February enjoys considerably less precipitation, totaling 36 mm (1.4 in) over 13 days, and a slightly lower humidity level of 77%. For a closer look at February's weather patterns, you can check Roseau weather in February.

In September, the weather tends to be warmer and more humid, with average temperatures ranging from a minimum of 25°C (78°F) to a maximum of 29°C (84°F). This month also experiences significant rainfall, with about 114 mm (4.5 in) spread over 17 days, leading to a humidity level of around 80%. In contrast, March offers slightly cooler conditions, with average temperatures from a minimum of 23°C (73°F) to a maximum of 26°C (80°F). Additionally, precipitation is much less frequent in March, totaling 34 mm (1.3 in) over 14 days, and the humidity is slightly lower at 78%. For more detailed information, you can check Roseau weather in March.

In comparing the weather of September and April, September tends to be slightly warmer with average temperatures reaching 27°C (81°F) during the day and a maximum of 29°C (84°F). In contrast, April’s temperatures are milder, with averages around 25°C (78°F) and maximums of 27°C (81°F). Notably, September experiences significantly higher precipitation, totaling 114 mm (4.5 in) over approximately 17 days, compared to just 32 mm (1.3 in) over 12 days in April. Humidity levels are relatively high in both months, with September at 80% and April at 78%. For more detailed information, you can check out Roseau weather in April.

In comparing the weather of September and May, both months experience warm temperatures, but September tends to be slightly warmer with an average temperature of 27°C (81°F) compared to May's average of 26°C (79°F). September also sees higher maximum temperatures, reaching up to 29°C (84°F), while May peaks at 28°C (82°F). However, September is considerably wetter, with 114 mm (4.5 in) of precipitation over 17 days, compared to May's 35 mm (1.4 in) over just 10 days. Humidity levels remain constant at 80% for both months, creating a tropical feel. For a closer look at May's weather, you can refer to Roseau weather in May.

In comparing the weather between September and June, we note that September tends to be slightly warmer, with average temperatures reaching 27°C (81°F) and a maximum of 29°C (84°F), compared to June’s maximum of 28°C (82°F). Moreover, September experiences higher precipitation levels, with 114 mm (4.5 in) over 17 days, while June sees only 68 mm (2.7 in) over 14 days. Humidity remains relatively high in both months, with September at 80% and June at 82%. For more detailed insights, you can explore Roseau weather in June.

In comparing the weather between September and July, we can observe that both months feature similar minimum and average temperatures, with September slightly warmer at a maximum of 29°C (84°F) compared to July's maximum of 28°C (83°F). However, September experiences higher precipitation levels, totaling 114 mm (4.5 in) over 17 days, in contrast to July's 97 mm (3.8 in) over 20 days. Additionally, September's humidity is slightly lower at 80%, while July sees a higher humidity level at 84%. For a more detailed view, check out Roseau weather in July.

In comparing the weather of September to that of August, we see that both months have similar temperature ranges, with minimums of 25°C (77°F), average temperatures of 27°C (81°F), and maximums reaching 29°C (84°F). However, September experiences slightly higher precipitation, with 114 mm (4.5 in) over 17 days, compared to August's 109 mm (4.3 in) over 21 days. Humidity levels are also comparable, but September is a bit lower at 80% compared to August's 82%. For a more detailed look at August weather, visit Roseau weather in August.

September and October exhibit quite similar weather patterns, with both months maintaining an average temperature of around 27°C (81°F). Notably, the minimum and maximum temperatures are consistent as well, ranging from 25°C (78°F) to 29°C (84°F) in both months. However, October experiences slightly more precipitation, with 117 mm (4.6 in) recorded over 20 days, compared to September's 114 mm (4.5 in) over 17 days. Humidity levels remain steady at 80% for both months. For more detailed information, you can check Roseau weather in October.

In September, the weather is slightly warmer with average temperatures reaching up to 27°C (81°F), while November sees a marginal decrease, averaging at 26°C (80°F). Both months experience similar minimum temperatures of around 25°C (78°F), but September has a slightly higher maximum temperature of 29°C (84°F) compared to November’s 28°C (82°F). Precipitation is heavier in September, with 114 mm (4.5 in) over 17 days, whereas November receives 97 mm (3.8 in) spread over 20 days, indicating a wetter month despite slightly less overall rainfall. Humidity remains consistent at 80% in both months. For a more detailed overview, you can check Roseau weather in November.

In September, temperatures in Roseau are slightly warmer, with averages reaching 27°C (81°F) and a maximum of 29°C (84°F). The month experiences considerable rainfall, totaling 114 mm (4.5 in) over 17 days, coupled with high humidity levels at 80%. In contrast, December sees a slight decrease in temperature with averages of 26°C (79°F) and a maximum of 28°C (82°F). The month also enjoys significantly less precipitation, with only 53 mm (2.1 in) over 18 days, and humidity remains comparable at 79%. For more details, you can check Roseau weather in December.

Compare Roseau's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Roseau

In September, Roseau experiences a unique blend of warmth and moisture, characterized by its high humidity levels and frequent rainfall. The average temperature hovers around a comfortable 27°C, but it feels more tropical due to the 80% humidity. Unlike the drier months, September sees significant precipitation, with rain gracing the city on nearly half the days of the month. This shift invites lush greenery and vibrant landscapes, making it a time of renewal, albeit with the unpredictability of sudden showers. For those planning to visit, understanding this distinct weather pattern is essential—check out more about the climate in Roseau Roseau Climate.