St. Thomas Climate

Last updated: January 18, 2025

St. Thomas, Jamaica, exemplifies a tropical savanna climate classified under the Köppen-Geiger system as Aw. The region experiences a minimum temperature of 21°C (69°F) in March, gradually rising to an average of 26°C (79°F) throughout the year. The warming trend peaks in September, where temperatures can soar to a maximum of 31°C (89°F). This climate pattern fosters a vibrant ecosystem, offering a unique blend of warmth and humidity that defines the enchanting landscape of St. Thomas.

St. Thomas temperature by month

In St. Thomas, Jamaica, temperature patterns reveal a consistent warmth throughout the year, characteristic of its tropical climate. The year begins with mild temperatures, where January and February see minimums around 21°C (70°F) and averages of 25°C (77°F). As spring approaches in April and May, temperatures gradually rise, with minimums reaching 22°C (71°F) and 23°C (73°F) and maximums peaking at 29°C (85°F). The summer months of June through September showcase the highest temperatures, with maxima consistently hitting 31°C (88-89°F), while minimums remain stable around 24°C (75°F). The transition into autumn in October and November witnesses a slight cooling, yet temperatures remain pleasant, with average temperatures of 26-27°C (79-81°F) and maxima not dipping below 30°C (86°F). By December, the climate cools slightly, closing the year with averages of 25°C (78°F) and comfortable highs, creating a consistently warm and inviting climate throughout the seasons.

Monthly Temperatures in St. Thomas, Jamaica

The chart illustrates St. Thomas's temperature patterns throughout the year, with values aggregated from various locations across the region. It highlights seasonal variations and temperature changes across the months.
JanFebMarAprMayJunJulAugSepOctNovDec777676777980818181807978
Data source: St. Thomas temperature data aggregated from multiple regional locations, generated using Copernicus Climate Change Service information.
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The average of daily temperatures (24 hours) calculated across all days in the month.

Morant Bay experiences a varied climate throughout the year, with temperatures ranging from a minimum of 21°C (69°F) in March to a maximum of 31°C (89°F) in September. For more detailed information on the monthly temperatures in Morant Bay, visit monthly temperatures in Morant Bay.

Precipitation Patterns in St. Thomas

Precipitation in St. Thomas, Jamaica, exhibits notable seasonal variation, highlighting a clear wet season from May to November. The year begins relatively dry, with January and February receiving 68 mm and 62 mm of rainfall respectively. March and April see a slight increase, with rainfall measuring 85 mm and 88 mm, setting the stage for the wettest months. May marks a significant uptick in precipitation with 149 mm (5.9 in) over 21 days, followed by even heavier rains in August, totaling 155 mm (6.1 in). This trend continues into the fall, as September and October witness substantial rainfall, with October being particularly notable at 256 mm (10.1 in), occurring over 25 days.

The frequency of rainy days also reflects this seasonal pattern, with May experiencing the highest number of rainy days at 21. Following closely, June, August, and October maintain elevated rainfall days, which contribute to the lush tropical vegetation characteristic of the region. Meanwhile, the drier months of January and February, despite having fewer rain days, still ensure a moderate climate. Overall, St. Thomas experiences an annual total of varied precipitation, which is essential for sustaining its diverse ecosystem and agricultural practices, while also balancing the tropical allure for both residents and visitors alike.

Monthly Average Precipitation in St. Thomas, Jamaica

The average monthly precipitation in St. Thomas, providing insights into seasonal rainfall patterns and the region's precipitation trends throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec68628588149887015512225717689
Data source: St. Thomas precipitation data aggregated from multiple regional locations, generated using Copernicus Climate Change Service information.
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Sunshine Duration in St. Thomas

In St. Thomas, Jamaica, sunlight is abundant, with sunshine duration showcasing a clear seasonal trend. The year begins with 251 hours of sunshine in January, gradually increasing to 304 hours in February. March is particularly bright, featuring 347 hours, marking the transition into spring. As the region moves towards summer, April and May maintain high levels of sunshine with 344 hours and 332 hours, respectively. This trend peaks in July, where St. Thomas basks in an impressive 355 hours of sunshine—the highest for the year—before tapering slightly with 342 hours in August and 320 hours in September, signaling the beginning of the wet season.

As autumn approaches, sunshine hours begin to decline, dropping to 304 hours in October and further down to 291 hours in November. Nonetheless, December experiences a resurgence in sunlight with 316 hours, providing a warm close to the year. The overall pattern highlights a consistent rise in daylight hours from winter's shorter days to the long, sun-filled days of summer, offering a vibrant and inviting climate. This seasonal brightness not only enriches the natural beauty of St. Thomas but also enhances its appeal as a tropical getaway for visitors seeking sun-soaked adventures.

Monthly Sunshine in St. Thomas, Jamaica

Monthly sunshine duration represents the total hours of direct sunlight St. Thomas receives each month, excluding periods when the sun is obscured by clouds or other obstructions.
JanFebMarAprMayJunJulAugSepOctNovDec251h304h347h344h332h342h355h342h320h304h291h316h
Data source: St. Thomas sunshine duration data aggregated from multiple regional locations, generated using Copernicus Climate Change Service information.

St. Thomas UV Index Trends

In St. Thomas, Jamaica, the UV Index demonstrates a pronounced annual pattern, peaking during the summer months when sun exposure can be particularly intense. Starting the year, January records a UV Index of 9, categorized as very high, prompting a burn time of just 15 minutes. As the months progress into February and March, the UV Index rises significantly, reaching 11 and 13, respectively, both classified as extreme. April and May maintain this extreme status, hitting a peak UV Index of 14, with a critical exposure time reduced to just 10 minutes. This trend continues into the summer months of June, July, and August, where the UV Index remains at 13, emphasizing the need for protective measures against the sun's rays.

As autumn approaches, the UV Index experiences a gradual decline. By September and October, it drops slightly to 12, still indicating extreme levels of sun exposure. Interestingly, in November, the UV Index decreases to 9 once more, categorizing it as very high, while December closes the year with an 8, indicating a similar level of caution necessary for outdoor activities. Overall, St. Thomas presents a climate where vigilance against UV exposure is crucial throughout much of the year, especially during the hotter months when sun protection becomes paramount for health and safety.

Monthly Maximum UV Index for St. Thomas, Jamaica

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in St. Thomas. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec911131414131313121298
Data source: St. Thomas UV Index data aggregated from multiple regional locations, generated using Copernicus Climate Change Service information.

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.

Daylight Hours in St. Thomas

Daylight duration in St. Thomas, Jamaica, showcases a consistent pattern characteristic of its tropical climate, with minimal fluctuations throughout the year. The year begins with 11 hours of daylight in both January and February, providing a stable base for outdoor activities. As spring arrives, daylight begins to stretch gradually, with 12 hours available from March through May. This increase not only enhances daily life but also promotes vibrant natural activities, allowing residents and visitors to fully enjoy the rich landscapes and cultural experiences that St. Thomas has to offer.

The peak daylight months occur during the summer, where June and July benefit from 13 hours of sunlight, maximizing the potential for beach outings and exploration. As summer transitions into late summer and autumn, daylight starts to decrease gently, returning to 12 hours in August and September, before settling back to 11 hours by October through December. This steady variation in daylight duration underscores the island's tropical rhythm, offering a reliable and enjoyable environment for year-round activities while also implying seasonal adaptations for both residents and tourists alike.

Average Monthly Daylight Hours in St. Thomas, Jamaica

This chart shows the total daylight hours St. Thomas receives each month, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec670h692h722h752h777h790h783h761h732h702h676h663h
Data source: St. Thomas daylight hours, calculated based on aggregated data for various regional locations, determined by the times between sunrise and sunset.

Climate Highlights of St. Thomas's Popular Destinations

Morant Bay, Jamaica, experiences a tropical climate characterized by warm temperatures year-round, with monthly averages ranging from 24°C (76°F) in the cooler months to 27°C (81°F) in the summer. Precipitation varies significantly, peaking in October at 256 mm (10.1 in), while the sun shines most in July with 355 hours. The region enjoys warm weather throughout the year, with maximum temperatures reaching up to 31°C (88°F) in the summer months. For detailed climate data, visit Morant Bay climate.

Conclusion

In conclusion, St. Thomas, Jamaica, presents a captivating climatic profile characterized by generous sunshine, significant UV exposure, and consistent daylight duration throughout the year. The region's tropical savanna climate not only fosters a warm and inviting atmosphere but also influences seasonal activities and lifestyle choices for both locals and visitors. With peak sunshine and intense UV levels during the summer months, awareness of sun protection is essential. Conversely, the reliable daylight hours facilitate a variety of outdoor pursuits year-round. Understanding these climatic elements allows for enhanced planning and appreciation of the vibrant, natural beauty that St. Thomas has to offer.

Discover the Climate of St. Thomas's Places

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