September weather forecastGrantham, Jamaica
September
Weather in September
The first month of the autumn, September, is also a hot month in Grantham, Jamaica, with an average temperature ranging between min 23.3°C (73.9°F) and max 31.4°C (88.5°F).Temperature
The beginning of September records an average high-temperature of a still hot 31.4°C (88.5°F), almost echoing the conditions of the previous month. Grantham records a steady low-temperature average of 23.3°C (73.9°F) during September.Heat index
The average heat index in September is computed to be an extremely hot 42°C (107.6°F). Ensure additional precautions, heat exhaustion and heat cramps may be expected. Heatstroke could occur from sustained activity.Realize that the values for the heat index are set for shaded places and light winds. A direct sunlight exposure may boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', evaluates the perceived heat by adding the effect of moisture in the air. The influence of weather can be personal, changing with an individual's body mass, height, and level of physical exertion. Considering the impact of direct sunlight, it's possible for the heat index to surge by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Children frequently do not comprehend the need for rest and hydration. Thirst is an advanced stage of dehydration - staying hydrated, especially during extended physical exercises, is essential.
By perspiring, the human body can shed its excessive warmth since evaporated sweat cools it off. Under high air temperature and high humidity (high heat index) conditions, the body's ability to perspire is compromised, increasing the sensation of heat. When body temperature rises due to excess heat gain beyond its removal capability, one might experience heat-related disorders.
Humidity
In Grantham, the average relative humidity in September is 79%.Rainfall
In Grantham, during September, the rain falls for 23.1 days and regularly aggregates up to 106mm (4.17") of precipitation. Throughout the year, there are 265.1 rainfall days, and 806mm (31.73") of precipitation is accumulated.Daylight
In September, the average length of the day in Grantham is 12h and 14min.On the first day of the month, sunrise is at 05:53 and sunset at 18:21. On the last day of September, in Grantham, sunrise is at 05:57 and sunset at 17:56 EST.
Sunshine
The average sunshine in September in Grantham is 10.9h.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 reading of 6 to 7 represents a high threat to health from unsafe exposure to UV radiation for the average person.Note: In September, a regular UV index of 6 translates into these guidelines:
Follow precautions and abide by sun safety rules. Deterrence of sunburn is imperative. From 10 a.m. to 4 p.m., when UV radiation is at its strongest, limit direct exposure to the Sun and note that shade structures may not provide full sun protection. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Grantham, Jamaica
- Average high temperature in September: 31.4°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 September: 23.3°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 September
Grantham, Jamaica
- Average pressure in September: 1012.3mbar
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 September
Grantham, Jamaica
- Average wind speed in September: 6.8km/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 September
Grantham, Jamaica
- Average humidity in September: 79%
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 September
Grantham, Jamaica
- Average rainfall in September: 106mm
The wettest month (with the highest rainfall) is October (123mm).
The driest month (with the least rainfall) is January (26mm).
Average rainfall days in September
Grantham, Jamaica
- Average rainfall days in September: 23.1 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 September /
Average sunshine in September
Grantham, Jamaica
- Average daylight in September: 12h and 12min
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 September: 10h and 54min
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 September
Grantham, Jamaica
- Average sunshine days in September: 1.7 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 September
Grantham, Jamaica
- Average UV index in September: 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 September
Grantham, Jamaica
- Average cloud cover in September: 29
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 September
Grantham, Jamaica
- Average visibility in September: 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).
