September weather forecast
Kalmunai, Sri Lanka

As August bows out with a small hint of monsoon, September amplifies the rainfall right back to 81mm (3.19"). Climatic conditions elicit the sense of the approaching wet season. However, temperatures remain relatively high, providing a juxtaposed experience of warm days and sublime showers. It is recommended to carry umbrellas in anticipation of bouts of rain. Despite the fickle weather, September in Kalmunai manages to charm with its unique mix of climate parameters.

Temperature

The average high-temperature in Kalmunai during September registers at a still tropical 31.8°C (89.2°F), closely corresponding to the preceding month. An average temperature of 25.7°C (78.3°F) is recorded in Kalmunai during the nights in September.

Heat index

September's heat index is estimated at a blistering 41°C (105.8°F). Take more safety measures, heat exhaustion and heat cramps are potential outcomes. Persistent activity might lead to heatstroke.
Know that the heat index computations account for shaded terrains and slight winds. The direct sun can potentially cause the heat index to increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is what the temperature feels like to the human body when the air temperature is combined with the relative humidity. Additional factors encompassing metabolic differences, the level of physical activity, and clothing can impact the individual's perception of temperature. Do note, being directly under sun rays can amplify the heat you feel, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children frequently do not understand the need for recuperation and hydration. Thirst, being a late manifestation of dehydration, underlines the need to hydrate frequently, especially when engaging in prolonged physical exercises.
Perspiring is a crucial mechanism for the human body, allowing it to release excessive warmth through evaporating sweat. When there is abundant moisture in the air, the body's cooling through the evaporation process becomes less effective, leading to the sensation of overheating. When the heat gained surpasses the body's cooling capacity, temperatures rise, signaling potential health concerns.

Humidity

In September, the average relative humidity is 72%.

Rainfall

In September, in Kalmunai, the rain falls for 22 days. Throughout September, 81mm (3.19") of precipitation is accumulated. In Kalmunai, during the entire year, the rain falls for 237.8 days and collects up to 1259mm (49.57") of precipitation.

Sea temperature

In Kalmunai, the average seawater temperature in September is 28.7°C (83.7°F).
Note: Engaging in water activities, such as swimming or diving, in temperatures from 25°C (77°F) to 29°C (84.2°F) is very pleasurable for extended periods, without any discomfort.

Daylight

In September, the average length of the day is 12h and 10min.
On the first day of September, sunrise is at 05:54 and sunset at 18:10. On the last day of the month, sunrise is at 05:50 and sunset at 17:54 +0530.

Sunshine

The average sunshine in September in Kalmunai is 10.7h.

UV index

January through October, with an average maximum UV index of 7, are months with the highest UV index in Kalmunai. A UV Index of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for the ordinary person.
Note: The maximum daily UV index, 7 in September, converts into the following recommendations:
Take precautions and utilize sun safety practices. Protection against skin and eye damage is required. Avoid direct exposure to the Sun between 10 a.m. and 4 p.m., the peak period for UV radiation, noting that objects like parasols or canopies might not offer complete sun protection. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Attention! The reflection of both water and sand can increase the intensity of UV rays.