December weather forecastGrantham, Jamaica
December
Weather in December
The first month of the winter, December, is also a moderately hot month in Grantham, Jamaica, with an average temperature varying between 21.5°C (70.7°F) and 28.9°C (84°F).Temperature
The advent of December denotes an average high-temperature of a still warm 28.9°C (84°F), subtly different from November's 29.7°C (85.5°F). Throughout the month of December, Grantham reports a steady low-temperature average of 21.5°C (70.7°F).Heat index
The average heat index in December is computed to be a very hot 35°C (95°F). Undertake extra safety actions, heat cramps and heat exhaustion are expected. Heatstroke may result from lengthy activity.Observations indicate that the heat index values are for shady locations with light wind. Exposure to unobstructed sunshine could lead to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', offers an insight into how hot it feels when we factor in moisture content. A person's impression of weather can be swayed by numerous aspects, among them metabolic variations, pregnancy, and activity levels. Given direct exposure to sunlight, one might experience a rise in the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Children often overlook the need for breaks and fluid intake. Thirst is a late-stage sign of dehydration - hence, it is necessary to stay hydrated, especially during extended periods of physical activities.
Perspiring is a crucial mechanism for the human body, allowing it to release excessive warmth through evaporating sweat. When relative humidity is heightened, it slows the rate of evaporation, thereby decreasing the body's ability to shed heat and creating a sensation of overheating. Excessive heat gain, when not shed effectively by the body, can result in increasing body temperatures and related hazards.
Humidity
The months with the highest humidity in Grantham are October through December, with an average relative humidity of 81%.Rainfall
In December, the rain falls for 19.9 days. Throughout December, 42mm (1.65") of precipitation is accumulated. In Grantham, during the entire year, the rain falls for 265.1 days and collects up to 806mm (31.73") of precipitation.Daylight
The month with the shortest days is December, with an average of 11h and 6min of daylight.On the first day of the month, sunrise is at 06:23 and sunset at 17:30. On the last day of December, sunrise is at 06:38 and sunset at 17:42 EST.
Sunshine
December has the least sunshine of the year in Grantham, with an average of 6.7h of sunshine.UV index
January through April, September, November and December, with an average maximum UV index of 6, are months with the lowest UV index in Grantham. A UV Index of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV radiation for the average person.Note: A daily high UV index of 6 in December leads to these guidelines:
Use protective steps and abide by sun safety guidelines. Safeguarding against skin and eye harm is necessary. Minimize exposure to direct sunlight and seek shade from 10 a.m. to 4 p.m., when UV radiation is most intense, but remember that shade structures may not offer complete protection. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Grantham, Jamaica
- Average high temperature in December: 28.9°C
The warmest months (with the highest average high temperature) are July and August (31.7°C).
The month with the lowest average high temperature is January (28.4°C).
- Average low temperature in December: 21.5°C
The month with the highest average low temperature is August (23.8°C).
The coldest month (with the lowest average low temperature) is January (20.5°C).
Average pressure in December
Grantham, Jamaica
- Average pressure in December: 1014.4mbar
The month with the highest atmospheric pressure is January (1015.5mbar).
The month with the lowest atmospheric pressure is October (1011.5mbar).
Average wind speed in December
Grantham, Jamaica
- Average wind speed in December: 7.3km/h
The windiest month (with the highest average wind speed) is June (9km/h).
The calmest month (with the lowest average wind speed) is November (6.6km/h).
Average humidity in December
Grantham, Jamaica
- Average humidity in December: 81%
The months with the highest relative humidity are October, November and December (81%).
The months with the lowest relative humidity are March, July and August (77%).
Average rainfall in December
Grantham, Jamaica
- Average rainfall in December: 42mm
The wettest month (with the highest rainfall) is October (123mm).
The driest month (with the least rainfall) is January (26mm).
Average rainfall days in December
Grantham, Jamaica
- Average rainfall days in December: 19.9 days
The month with the highest number of rainy days is October (26.5 days).
The month with the least rainy days is February (19.2 days).
Average daylight in December /
Average sunshine in December
Grantham, Jamaica
- Average daylight in December: 11h and 6min
The month with the longest days is June (Average daylight: 13h and 12min).
The month with the shortest days is December (Average daylight: 11h and 6min).
- Average sunshine in December: 6h and 42min
The month with the most sunshine is August (Average sunshine: 11h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in December
Grantham, Jamaica
- Average sunshine days in December: 4.6 days
The month with the most sunshine days is January (6 days).
The month with the least sunshine days is October (1.5 days).
Average UV index in December
Grantham, Jamaica
- Average UV index in December: 6
The months with the highest UV index are May, June, July, August and October (UV index 7).
The months with the lowest UV index are January, February, March, April, September, November and December (UV index 6).
Average cloud cover in December
Grantham, Jamaica
- Average cloud cover in December: 32
The month with the most cloud cover is June (Cloud cover 38).
The month with the least cloud cover is September (Cloud cover 29).
Average visibility in December
Grantham, Jamaica
- Average visibility in December: 9km
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (9km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (9km).
