Last updated: August 31, 2025
Experience the tropical allure of Basseterre, Saint Kitts and Nevis in September, where the average temperature hovers around 27°C (82°F), with maximums reaching 29°C (84°F) and minimums dipping to 25°C (78°F). This month is characterized by a notable humidity level of 80%, contributing to the island's lush scenery. Prepare for frequent showers, as September sees 146 mm (5.7 in) of rainfall over 20 days, inviting vibrant flora and a refreshing atmosphere. Whether you're exploring local attractions or simply lounging on the beach, the weather offers a warm yet invigorating experience!
In September, Basseterre, Saint Kitts and Nevis, experiences a warm climate with temperatures that reflect the Caribbean's tropical allure. The month boasts a minimum temperature of 25°C (78°F), complemented by an average of 27°C (82°F) and a peak of 29°C (84°F). This slight increase from the previous months signals a transition towards the warmer season, with both nighttime lows and daytime highs maintaining a consistent warmth reminiscent of July and August. As summer wanes, the balmy heat and inviting breezes make September a delightful time to soak in the vibrant island atmosphere, perfect for both relaxation and exploration.
In September, Basseterre experiences a notable surge in precipitation, with a striking average of 146 mm (5.7 in), marking it as the wettest month of the year. This increase is reflected in the 20 rainy days that often characterize the month, setting the stage for lush landscapes and vibrant greenery across the island. Following the trend established in the summer months, the rainfall in September significantly surpasses the figures seen in August, which recorded 101 mm (4.0 in) over 16 days. The pattern of increasing rainfall from the drier early months of the year to this peak highlights Saint Kitts and Nevis's tropical climate, making September a key period for those looking to experience the island's natural beauty, albeit with an umbrella in hand.
September in Basseterre, Saint Kitts and Nevis, experiences an average humidity of 80%, marking a slight decline from the peak levels seen in the previous summer months. This drop follows a steady increase throughout the summer, where humidity reached 83% in July and remained high at 82% in August. As the island transitions into fall, the humidity begins to dip gradually, signaling a shift in the tropical climate. Overall, September’s humidity reflects a balance of warmth and comfort, with conditions still favorable for those enjoying the lush Caribbean environment, while hinting at the approaching drier months ahead.
In September, Basseterre, Saint Kitts and Nevis typically experiences a UV Index of 14, signaling an extreme exposure category that warrants caution. This trend aligns with the summer months, where the UV Index reaches its annual peak; from June to August, it consistently hovers at 13. As you soak in the sun, keep in mind that the burn time is just 10 minutes, making it crucial to apply sunscreen and seek shade during the hottest hours. As the year transitions into October, there is a slight dip to 12, but the need for sun protection remains paramount. For more detailed information on UV levels, check out Basseterre UV Index.
UV Risk Categories
As September arrives in Basseterre, Saint Kitts and Nevis, the sun continues to shine brightly, granting the island an impressive 321 hours of sunshine this month. Following the vibrant peak of summer, where July dazzles with an impressive 362 hours, September maintains a delightful tropical warmth, though slightly dipping compared to the peak months. This trend of abundant daylight persists as autumn approaches, with October and November also showcasing considerable sunshine, averaging 318 and 308 hours respectively. Comparing September’s hours to earlier months reveals a gentle transition from the summer highs, yet still offers ample opportunity for sun-soaked adventures in picturesque surroundings. Whether lounging on the beach or exploring lush landscapes, September’s golden rays provide an inviting backdrop for both relaxation and discovery on this enchanting Caribbean island.
In September, Basseterre, Saint Kitts and Nevis, enjoys a 60% chance of sunny weather, making it one of the more favorable months for sunshine on the island. This probability marks an increase from the preceding months of July and August, which hover around the mid-40s. As the season transitions into fall, the likelihood of clear skies starts to climb again, reflecting a broader trend of improving sun exposure after the relatively overcast summer months. Notably, September’s sunshine likelihood is closely aligned with the post-hurricane season in October, both offering a delightful backdrop for visitors seeking to bask in tropical sunshine.
In Basseterre, Saint Kitts and Nevis, the daylight duration elegantly transitions throughout the year, reflecting the island's tropical climate. As we progress from January to March, daylight gradually increases, peaking at 13 hours during the height of summer in June and July. This sunny abundance then tapers off slightly, settling back to 12 hours in August and September, creating a delightful balance as the rainy season approaches. By October, daylight begins its decline again, returning to 11 hours as the year draws to a close. This rhythmic ebb and flow of sunlight not only highlights the island’s seasonal shifts but also sets the perfect backdrop for outdoor adventures and leisurely pursuits year-round.
As September rolls into Basseterre, Saint Kitts and Nevis, the winds begin to mellow, showcasing an average speed of 5.3 m/s (12 mph). This marks a noticeable dip from the summer months, where the wind had been consistently brisk, averaging around 8.5 m/s (19 mph) in July and 8.3 m/s (19 mph) in June. The gentle breezes of September create a serene atmosphere, perfect for enjoying the tranquil coastal views and vibrant sunsets. Following this seasonal lull, wind speeds gradually begin to increase again in October, hinting at the island's dynamic climatic patterns. The transition from the lively summer gales to September’s calming whispers offers a unique charm, inviting locals and visitors alike to savor the beauty of the island in a quieter, more reflective setting.
Weather in Basseterre varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Basseterre, focusing on differences in temperature, rainfall, humidity, and UV levels.
In comparing the weather between September and January, we see some notable differences. September tends to be warmer 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 (82°F). However, it is also wetter, receiving 146 mm (5.7 in) of precipitation over 20 days, which contributes to a high humidity level of 80%. In contrast, January experiences cooler temperatures, with a minimum of 23°C (73°F) and a maximum of 27°C (81°F), averaging 25°C (78°F). Precipitation is significantly lower in January, at just 35 mm (1.4 in) over 13 days, along with a slightly lower humidity of 77%. For more details, you can explore Basseterre weather in January.
September and February present notably different weather conditions. In September, temperatures are warmer, with a minimum of 25°C (78°F) and an average of 27°C (82°F), often peaking at 29°C (84°F). This month also experiences significant rainfall, totaling 146 mm (5.7 in) over about 20 days, coupled with high humidity levels at 80%. In contrast, February offers milder weather with a minimum of 22°C (72°F) and an average temperature of 25°C (77°F), reaching a maximum of 26°C (80°F). Rainfall is considerably less, at just 35 mm (1.4 in) spread over 12 days, and humidity is slightly lower at 77%. For more detailed information about February weather, you can visit Basseterre weather in February.
September and March each present distinct weather characteristics. In September, temperatures are typically warmer, with a minimum of 25°C (78°F) and an average of 27°C (82°F), while March features slightly cooler temperatures, with a minimum of 22°C (73°F) and an average of 25°C (77°F). Moreover, September experiences significantly more rainfall, with an average precipitation of 146 mm (5.7 in) over 20 days, compared to March's 27 mm (1.1 in) over just 10 days. Humidity levels are relatively high in both months, with September at 80% and March slightly lower at 77%. For more detailed information on March weather, you can check Basseterre weather in March.
In comparing the weather in September and April, September tends to be warmer and wetter. With average temperatures reaching up to 27°C (82°F) and a high of 29°C (84°F), September experiences significant precipitation, totaling 146 mm (5.7 in) over approximately 20 days, contributing to a high humidity level of 80%. In contrast, April has slightly cooler temperatures, averaging 25°C (78°F) with a maximum of 27°C (81°F), and considerably less rainfall, amounting to only 41 mm (1.6 in) over 13 days. Humidity in April is somewhat lower at 78%, making it a more pleasant month overall. For a detailed look at the weather in April, visit Basseterre weather in April.
When comparing September and May weather, both months exhibit warm temperatures, but September tends to be slightly hotter with average temperatures reaching 27°C (82°F), whereas May averages at 26°C (79°F). Although minimum temperatures are closely aligned at 25°C (78°F) in September and 24°C (75°F) in May, September is marked by significantly higher precipitation, totaling 146 mm (5.7 in) over 20 rainy days, compared to May’s 53 mm (2.1 in) over just 14 days. The humidity levels remain quite similar, with September at 80% and May slightly lower at 79%. For more detailed weather information, check Basseterre weather in May.
When comparing the weather in September and June, we observe slight differences in temperature and precipitation. Both months feature a minimum temperature of around 25°C (78°F) and an average of 27°C (82°F); however, September sees a marginally higher maximum temperature of 29°C (84°F) compared to June's 28°C (83°F). In terms of rainfall, September experiences significantly more precipitation, with 146 mm (5.7 in) over 20 days, while June has a much lighter rainfall of 51 mm (2.0 in) spread across only 12 days. Humidity levels are similar in both months, hovering around 80-81%. For a detailed look at the weather specifics in June, you can check Basseterre weather in June.
When comparing the weather in September to that of July, we see some notable differences despite their similar temperature ranges. Both months have a minimum temperature of around 25°C (77-78°F) and an average high of 29°C (84°F), but September experiences significantly more precipitation, totaling 146 mm (5.7 in) over 20 days, compared to July’s 78 mm (3.1 in) over 18 days. Additionally, September has a slightly lower humidity level at 80% compared to July's 83%. This increase in rain during September may indicate a shift towards a wetter climate as the month progresses. For more details about the July weather, you can visit Basseterre weather in July.
In comparing the weather of September and August, we find that both months share similar temperature ranges, with minimums at 25°C (77°F), average temperatures around 27°C (82°F), and maximums hitting 29°C (84°F). However, September experiences significantly more rainfall, with 146 mm (5.7 in) over 20 days, compared to August's 101 mm (4.0 in) across 16 days. Humidity levels are also quite comparable, at 80% for September and 82% for August. For a more detailed look at August weather, you can visit Basseterre weather in August.
In comparing the weather between September and October, we observe that both months maintain a similar temperature range, with September having a minimum of 25°C and a maximum of 29°C, while October mirrors this with the same min and a slightly higher max of 29°C. Precipitation also decreases from 146 mm in September over 20 days to 112 mm in October over 18 days, indicating a slight improvement in weather conditions as the month progresses. Additionally, humidity remains relatively consistent, starting at 80% in September and dropping slightly to 79% in October. For a detailed look at what to expect during October, check out Basseterre weather in October.
In comparing the weather of September and November, we see that September tends to be slightly warmer overall, with average temperatures ranging from a minimum of 25°C (78°F) to a maximum of 29°C (84°F). In contrast, November features a slightly cooler range with temperatures from a minimum of 24°C (76°F) to a maximum of 28°C (83°F). Additionally, September experiences higher precipitation, totaling 146 mm (5.7 in) over 20 days, compared to November's 94 mm (3.7 in) over 17 days, resulting in a drier atmosphere in November. Humidity levels remain quite similar in both months at 80% in September and 79% in November, suggesting that while the temperature may be a bit more pleasant in November, the overall climate remains humid. For more detailed information about the weather in November, you can check Basseterre weather in November.
In September, the weather is typically warm and humid, with average temperatures around 27°C (82°F) and maximums reaching 29°C (84°F). The month experiences significant rainfall, with about 146 mm (5.7 in) spread over 20 days, resulting in a humidity level of 80%. In contrast, December presents slightly cooler conditions, with an average temperature of 26°C (79°F) and maximums of 28°C (82°F). Precipitation decreases markedly to 50 mm (2.0 in) over 17 days, and humidity drops to 78%. For a closer look at the December climate, you can visit Basseterre weather in December.
As September rolls in, Basseterre experiences a unique shift in weather patterns that distinguishes it from other months. With higher humidity levels and an increase in precipitation, this period often feels more tropical, contributing to the lush ambiance of the island. While temperatures remain warm and inviting, the frequent rain showers serve as a refreshing contrast to the heat, creating a dynamic climate that is both challenging and invigorating. For those looking to explore the vibrant landscapes and rich culture of Saint Kitts, understanding this transitional weather is essential. To learn more about Basseterre's year-round climate, check out Basseterre Climate.