September weather forecast
Biratnagar, Nepal

As monsoon season begins to fade, September in Biratnagar reveals a decrease in rainfall to 123mm (4.84"). The temperature comes down further, providing a much-needed reprieve from the preceding scorching months. Predominantly, the weather is warmer, with the sun casting its glow for about 9.7 hours in a day. With precipitation levels dwindling and temperatures dipping, September brings forth the onset of autumn. The end of the monsoon season signals a revival in outdoor activities, thanks to the more predictable weather pattern.

Temperature

The arrival of September records an average high-temperature of a still hot 32.9°C (91.2°F), closely related to the 33.9°C (93°F) observed in August. The average temperature during September nights is registered at a warm 25.4°C (77.7°F).

Heat index

In September, the average heat index is calculated to be a life-threatening hot 45°C (113°F). Take note: Heat exhaustion and heat cramps are expected. Heatstroke can occur with prolonged effort.
Heat index's context suggests values are appropriate for shady areas and slight breezes. The heat index could see an increase by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is a single figure representing how weather conditions feel when combining temperature and humidity. The influence of weather is personal, with varied individuals experiencing it differently due to differences in body mass, stature, and physical exertion levels. Direct sunlight exposure should be noted as it has the potential to increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. In general, children are more at risk than adults because they sweat less. Furthermore, the large skin surface compared to their small bodies and the high heat production due to their actions contribute to this vulnerability.
The human body keeps its cool primarily through perspiration, as this process enables sweat to evaporate, taking away the excess heat. When relative humidity increases, the body's capacity to evaporate heat decreases, leading to a heightened sense of warmth. When the body's heat gain surpasses its removal capacity, body temperature starts to climb, leading to potential heat-related ailments.

Humidity

July and September, with an average relative humidity of 74%, are the most humid months in Biratnagar.

Rainfall

In September, the rain falls for 18.5 days. Throughout September, 123mm (4.84") of precipitation is accumulated. Throughout the year, there are 128.5 rainfall days, and 872mm (34.33") of precipitation is accumulated.

Daylight

The average length of the day in September is 12h and 19min.
On the first day of the month, sunrise is at 5:35 am and sunset at 6:15 pm. On the last day of September, in Biratnagar, sunrise is at 5:48 am and sunset at 5:43 pm +0545.

Sunshine

In September, the average sunshine in Biratnagar is 9.7h.

UV index

In Biratnagar, the average daily maximum UV index in September is 7. A UV Index estimate of 6 to 7 represents a high health vulnerability from exposure to the Sun's UV radiation for average individuals.
Note: A maximum daily UV index of 7 during September morphs into the following directions:
Persist with precautions and heed sun safety advice. Prevention of sunburn is compulsory. Between 10 a.m. and 4 p.m., the Sun's UV radiation is at its peak. Limit your exposure to direct sunlight during these hours. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.