January weather forecast
Port Royal, Jamaica

January in Port Royal, Jamaica kickstarts the year with steady weather conditions characterized by moderate rainfall and constant temperatures. Despite it being one of the cooler months, temperatures remain pleasantly warm, practically falling in line with the season's tropical climate. The anticipated rainfall measures up to 52mm (2.05") and the city experiences an average of 23.9 days of rain throughout the month. The marine influence is notable, with a sea temperature, only slightly lower than the air temperature. As the year begins, residents and visitors can expect to enjoy a reasonable amount of daylight and sunshine hours, with relatively clear visibility.

Temperature

January and February, when the average high-temperature in Port Royal reaches 27.3°C (81.1°F), are the coldest months.

Heat index

Throughout January, the heat index is appraised at a hot 30°C (86°F). If one continues to be active during enduring exposure, it could result in fatigue and heat cramps.
Data suggests that the heat index is set for environments in shade and with a light wind. Being exposed to direct sunshine might trigger a heat index increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', comes about by integrating the temperature readings with the humidity levels. Additional factors encompassing metabolic differences, the level of physical activity, and clothing can impact the individual's perception of temperature. Always consider that direct sunlight exposure might heighten the heat's effects, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical to babies and toddlers. Youths are typically more endangered than adults since they usually sweat less. Their larger skin surface concerning their smaller bodies and higher heat production due to activity further adds to their vulnerability.

Humidity

The average relative humidity in January is 80%.

Rainfall

In Port Royal, during January, the rain falls for 23.9 days and regularly aggregates up to 52mm (2.05") of precipitation. In Port Royal, during the entire year, the rain falls for 310.9 days and collects up to 1286mm (50.63") of precipitation.

Sea temperature

In Port Royal, the average seawater temperature in January is 27.1°C (80.8°F).
Note: Water temperatures between 25°C (77°F) and 29°C (84.2°F) are ideal for swimming, diving, and other activities, ensuring comfort and enjoyment for lengthened periods.

Daylight

In January, the average length of the day is 11h and 12min.
On the first day of the month, sunrise is at 06:38 and sunset at 17:43. On the last day of January, sunrise is at 06:40 and sunset at 18:01 EST.

Sunshine

The average sunshine in January is 6.8h.

UV index

The months with the lowest UV index are January through May, November and December, with an average maximum UV index of 6. A UV Index value of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for the average person.
Note: The UV index of 6 during January leads to these advisories:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. Seek shade and limit direct Sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its peak, but be aware that not all shade structures provide complete sun protection. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Beware! Reflecting off water and sand, UV rays are much stronger.