September Weather in Charlestown, Saint Kitts and Nevis

Last updated: August 31, 2025

September in Charlestown, Saint Kitts and Nevis presents a tropical experience marked by warm temperatures and significant humidity. The maximum temperature reaches around 29°C (85°F), with an average of 28°C (82°F), creating a comfortable yet sultry atmosphere. Minimum temperatures hover around 25°C (77°F), providing a mild respite at night. Visitors can expect 147 mm (5.8 in) of rainfall over approximately 19 days, indicating a wet month conducive for lush landscapes. With humidity levels at a high 80%, it's essential to stay hydrated and embrace the vibrant, tropical essence of this Caribbean paradise.

September Temperature in Charlestown

In September, Charlestown, Saint Kitts and Nevis experiences a delightful blend of warmth and humidity, with temperatures showcasing a slight upward trend compared to the preceding months. The minimum temperature hovers around 25°C (77°F), while the *average climbs to a cozy 28°C (82°F), reaching a pleasant *maximum of 29°C (85°F). This marks a continuation of the summer heat, as September mirrors August's sultry embrace, making it an ideal time for beach lovers and outdoor enthusiasts. As the month progresses, the temperatures remain consistently warm, creating a lush and inviting atmosphere that embodies the tropical charm of this Caribbean paradise.

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

The chart illustrates September temperature patterns in Charlestown, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Charlestown, 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).
JanFebMarAprMayJunJulAugSepOctNovDec777777787980818182818079
Data source: Temperature data for Charlestown 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 Charlestown

In September, Charlestown, Saint Kitts and Nevis experiences a significant spike in precipitation, with an impressive total of 147 mm (5.8 in), marking it as the wettest month of the year. This increase is a notable departure from the preceding months, where rainfall remains relatively moderate. Interestingly, the 19 days of rainfall in September aligns with the trend of higher precipitation days observed during the peak of the wet season, as seen in July and August as well. The gradual rise in rainfall from January's modest 35 mm to the lush September deluge hints at the vibrant climatic transition, underscoring the island's lush tropical landscape and setting the stage for a distinctly green and flourishing environment.

September Precipitation Trends in Charlestown

The chart displays monthly precipitation patterns in Charlestown, 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 Charlestown, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec35352738504976941471089349
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Charlestown

September in Charlestown, Saint Kitts and Nevis, experiences a humidity level of 80%, reflecting a slight decline from the peak humidity observed in the hotter summer months of July (83%) and August (82%). This drop signifies a gradual transition towards the drier months of October and November, where humidity levels hover around 79%. Throughout the year, humidity remains relatively high, fluctuating between 77% and 83%, which highlights the tropical climate's consistency. As the island approaches the end of the wet season, September's weather offers a blend of warmth and moisture, setting the stage for the upcoming shift in atmospheric conditions.

September Average Humidity in Charlestown

This chart illustrates the average monthly humidity levels in Charlestown, 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 Charlestown is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec77%77%77%78%79%81%83%82%80%79%79%78%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Charlestown

In September, Charlestown, Saint Kitts and Nevis, experiences a high UV Index of 13, categorized as extreme, resulting in a burn time of just 10 minutes under direct sun exposure. This trend of elevated UV levels continues from the hotter summer months, where the index remains consistently high at 13 from April through August. Notably, the UV Index in September mirrors the intensity seen in the preceding months, highlighting a persistent need for sun protection. As we transition into October, the UV Index slightly decreases to 12, but vigilance is still essential to safeguard against the sun's harmful rays. For those looking to better understand their sun exposure risks, further information can be found at Charlestown UV Index.

Maximum UV Index Levels in Charlestown for September

The chart shows the monthly maximum UV Index (UVI) for Charlestown 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 Charlestown typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec911131313131313131299
Data source: Charlestown 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 Charlestown

September in Charlestown, Saint Kitts and Nevis, continues the island's trend of abundant sunshine, boasting 322 hours of bright, beautiful light. As summer edges toward fall, the sun-soaked days remain plentiful, though slightly less than the peak our sandy shores enjoyed in July with 362 hours. This subtle dip in sunshine aligns with the typical transition of the months, as August also reflected the lingering warmth with 352 hours. The consistent high levels of sunlight throughout the year, particularly from March to July, highlight the island's appeal as a tropical paradise, making every month an enticing option for sun-seekers. With October promising a still bright 318 hours, Charlestown's charm is undeniably enhanced by its radiant September days.

Monthly Sunshine Duration in Charlestown: September Highlighted

The September sunshine duration represents the total number of hours Charlestown 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.
JanFebMarAprMayJunJulAugSepOctNovDec262h302h350h347h359h340h362h352h322h318h309h326h
Data source: Charlestown September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Charlestown During September

In September, Charlestown, Saint Kitts and Nevis enjoys a 60% chance of sunny weather, marking a notable improvement compared to the cloudier months of June and July, which see chances as low as 24% and 47%, respectively. This trend indicates a return to more favorable conditions following the summer, as September generally offers better prospects for sunshine among the late summer months. The likelihood of sun increases further in the following months, with October’s 56% and November’s impressive 68% providing a pleasing transition into the drier season. Thus, if you're planning a visit in September, you can expect a warm and predominantly sunny climate, ideal for enjoying the beauty of this Caribbean gem.

Percentage of Sunny Days in September in Charlestown

The chart illustrates the percentage of sunny days in Charlestown 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 Charlestown experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec58%71%68%45%53%24%47%46%60%57%69%67%
Data source: Charlestown September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Charlestown in September

In September, Charlestown, Saint Kitts and Nevis enjoys a delightful 12 hours of daylight, maintaining the vibrant trend established in April and May. As the summer months of June and July offer their peak of 13 hours, September marks a gentle transition towards shorter days as autumn approaches, still granting ample sunlight. This consistent daylight duration reflects the tropical climate's steady rhythm, providing a perfect backdrop for outdoor activities and exploration. Following this pattern, October will usher in a slight decrease, bringing the daylight back to 11 hours as the year gradually winds down.

Average Daylight Hours in Charlestown for September

The chart illustrates the variation in daylight duration in Charlestown throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 13m11h 34m12h 2m12h 31m12h 55m13h 7m13h 1m12h 39m12h 12m11h 43m11h 18m11h 6m
Data source: Charlestown daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Charlestown

As summer gently bows out in September, the winds of Charlestown, Saint Kitts and Nevis, experience a noticeable shift. With an average wind speed of just 5.2 m/s (12 mph), September marks the calmest month of the year, considerably quieter compared to the brisk breezes of July and August. This reduction in wind speed signals the transition into the heart of the Caribbean's autumn, where the hustle of summer gives way to a more tranquil atmosphere. Notably, the winds have been gradually varying throughout the year, peaking in February at 9.2 m/s (21 mph) and showing a consistent decline as the year progresses towards September. This shift not only enhances the region's serene charm but also creates an inviting backdrop for those seeking a peaceful escape amidst nature's splendor.

Average September Wind Speed in Charlestown

The chart displays monthly wind speed patterns in Charlestown, 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.
JanFebMarAprMayJunJulAugSepOctNovDec7.29.27.56.67.48.28.47.25.2 m/s6.46.18.0
Data source: Charlestown September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Charlestown Compares to Other Months

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

In September, the weather is characterized by warmer temperatures, with an average of 28°C (82°F) and a high of 29°C (85°F), making it quite humid at 80%. However, this month also sees considerable rainfall, with precipitation amounting to 147 mm (5.8 in) over 19 days. In contrast, January experiences slightly cooler temperatures, averaging 25°C (78°F) with a maximum of 27°C (81°F) and lower humidity at 77%. Additionally, January has significantly less rainfall, with only 35 mm (1.4 in) over 13 days, making it a drier month overall. For more detailed information, check out Charlestown weather in January.

In September, temperatures are generally warmer with a minimum of 25°C (77°F) and an average of 28°C (82°F), peaking at a maximum of 29°C (85°F). This month also experiences significant rainfall, with 147 mm (5.8 in) over 19 days, contributing to a high humidity level of 80%. In contrast, February sees slightly cooler temperatures, with a minimum of 22°C (72°F), an average of 25°C (77°F), and a maximum of 27°C (80°F). Precipitation is considerably lower in February, totaling only 35 mm (1.4 in) over 11 days, and humidity is also a bit less at 77%. For more detailed insights about February weather, check out Charlestown weather in February.

In September, the weather is noticeably warmer with temperatures ranging from a minimum of 25°C (77°F) to a maximum of 29°C (85°F), with an average temperature of 28°C (82°F). The month also sees significant rainfall, averaging 147 mm (5.8 in) over 19 days, contributing to a high humidity level of 80%. In contrast, March offers a milder climate, with temperatures dipping slightly to a minimum of 22°C (73°F) and a maximum of 26°C (80°F), averaging 25°C (77°F). Additionally, precipitation in March is much lower at 27 mm (1.0 in) over just 9 days and the humidity is slightly less at 77%. For a detailed comparison, you can explore Charlestown weather in March.

In comparing the weather between September and April, September tends to be warmer and wetter. The average temperature in September is around 28°C (82°F), with maximums reaching 29°C (85°F), while April's average temperature is a bit cooler at 25°C (78°F), with maximums of 27°C (82°F). Additionally, September experiences significantly more rainfall, totaling 147 mm (5.8 in) over 19 days, compared to April's 38 mm (1.5 in) spread over 13 days. Humidity levels are similar, with September at 80% and April slightly lower at 78%. For a closer look at the specifics of April weather, visit Charlestown weather in April.

In comparing the weather between September and May, September tends to be warmer and wetter. With temperatures peaking at 29°C (85°F) and an average of 28°C (82°F), September experiences higher warmth compared to May, where the maximum temperature reaches 28°C (82°F) and averages around 26°C (79°F). However, September also sees significantly more rainfall, with 147 mm (5.8 in) spread over 19 days, while May only receives 50 mm (2.0 in) across 14 days. Humidity levels are quite similar in both months, hovering around 80% in September and 79% in May. For more detailed information on the weather in May, check out Charlestown weather in May.

September weather tends to be slightly warmer than June, with average temperatures reaching 28°C (82°F) compared to June's average of 27°C (81°F). While the minimum temperatures are quite comparable, September experiences higher maximum temperatures at 29°C (85°F), compared to June's 28°C (83°F). However, September is significantly wetter, with 147 mm (5.8 in) of precipitation over 19 days, contrasted with June's much drier conditions that only see 49 mm (1.9 in) over 12 days. Humidity remains relatively constant between the two months, with September at 80% and June at 81%. For a more detailed look at June conditions, you can check Charlestown weather in June.

In comparing the weather patterns of September and July, we can observe that both months have similar temperature ranges, with September experiencing slightly higher averages at 28°C (82°F) compared to July's 27°C (81°F). However, September is notably rainier, with a total precipitation of 147 mm (5.8 in) over 19 days, while July sees only 76 mm (3.0 in) during the same number of days. Humidity levels are also high in both months, with September at 80% and July slightly higher at 83%. For more details, check out Charlestown weather in July.

In comparing the weather of September to August, we see some notable differences. September typically has a minimum temperature of 25°C (77°F) and an average of 28°C (82°F), with a maximum reaching up to 29°C (85°F). This month also experiences higher precipitation, totaling 147 mm (5.8 in) over 19 days, resulting in humidity levels around 80%. In contrast, August maintains similar minimum and maximum temperatures, with an average of 27°C (82°F) and a lower precipitation of 94 mm (3.7 in) over 16 days, along with a slightly higher humidity of 82%. Overall, September is marked by increased rainfall and slightly higher humidity compared to August. For more details, you can check Charlestown weather in August.

September ushered in warmer weather with an average temperature of 28°C (82°F) and high humidity levels of 80%. The month saw significant rainfall, accumulating to 147 mm (5.8 in) over 19 days. In contrast, October offers slightly cooler conditions, with average temperatures decreasing to 27°C (81°F) while maintaining a similar high of 29°C (85°F). Precipitation also decreases to 108 mm (4.3 in) over 18 days, and humidity levels drop just slightly to 79%. For a detailed look at the weather patterns in October, you can check out Charlestown weather in October.

In comparing the weather between September and November, September tends to be slightly warmer with an average temperature of 28°C (82°F) and a maximum of 29°C (85°F), compared to November's average of 27°C (80°F) and maximum of 28°C (83°F). Additionally, September experiences significantly more precipitation, with 147 mm (5.8 in) of rainfall over 19 days, while November sees a decrease to 93 mm (3.6 in) over 17 days. Both months maintain high humidity levels, with September at 80% and November slightly lower at 79%. For more detailed information, you can check Charlestown weather in November.

In September, the weather features warmer temperatures with a minimum of 25°C (77°F) and an average high of 29°C (85°F), making it feel quite hot and humid, particularly with an 80% humidity level. The month is also characterized by significant rainfall, receiving around 147 mm (5.8 in) over 19 days. In contrast, December sees slightly cooler temperatures, with a minimum of 24°C (75°F) and an average high of 28°C (82°F). Precipitation drops notably to 49 mm (1.9 in) over 18 days, and humidity decreases slightly to 78%, creating a more comfortable atmosphere. For more detailed information, visit Charlestown weather in December.

Compare Charlestown's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Charlestown

As September unfolds in Charlestown, the weather presents a unique blend of warmth and humidity, with temperatures remaining comfortably high, but the air feels noticeably thicker with an average humidity of 80%. While the daily highs can reach a toasty 29°C, this month also witnesses increased rainfall, with nearly half the days experiencing some precipitation. This combination of warmth and wetness distinguishes September from other months, making it essential for visitors to prepare for frequent showers. For more insights into the region’s climate trends, you can explore Charlestown Climate.