September weather forecast
Merida, Mexico

With the commencement of September, the weather takes another turn in Merida. The city receives the highest amount of rainfall, up to 70mm on average, as compared to other months. Even though the rainfall is significant, temperatures remain quite high. The overall weather can be described as rainy and humid, making it ideal for indoor activities. Since outdoor activities may get hindered due to significant rainfall, flexible plans are advised.

Temperature

August's transformation into September witnesses an average high-temperature of a tropical 33.6°C in Merida, noting a minor change from the preceding month. Throughout September, Merida witnesses a consistent average low-temperature of 23.3°C.

Heat index

During September, the heat index is computed to be a life-threatening hot 49°C. Be cautious: Heat exhaustion along with heat cramps are predicted. Heatstroke is a possible consequence of continuous physical effort.
The standards for the heat index are set for locations in shade and under light breezes. Direct sunlight might cause an increase of up to 15 Fahrenheit (8 Celsius) degrees in the heat index.
Note: The heat index, also known as 'real feel' or 'felt air temperature', comes about by integrating the temperature readings with the humidity levels. The impact of weather is personal, differing among a variety of people based on differences in body mass, height, and the level of physical exertion. Direct exposure to sun rays can potentially augment the heat sensation, elevating the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Young ones often disregard the necessity to rest and hydrate. Thirst usually indicates advanced dehydration - hence, it is key to stay hydrated, particularly during ongoing physical activities.
To combat high temperatures, the human body perspires and relies on sweat evaporation for cooling. In situations of high air temperature combined with high humidity (significant heat index), the body's ability to perspire is reduced, heightening the sense of warmth. When the body is unable to balance heat gain, its temperature elevates, which may induce thermal illnesses.

Humidity

September and October, with an average relative humidity of 78%, are the most humid months in Merida.

Rainfall

In Merida, during September, the rain falls for 20.4 days and regularly aggregates up to 70mm of precipitation. In Merida, during the entire year, the rain falls for 167.3 days and collects up to 536mm of precipitation.

Daylight

In September, the average length of the day is 12h and 16min.
On the first day of the month, sunrise is at 5:42 am and sunset at 6:14 pm. On the last day of September, in Merida, sunrise is at 5:49 am and sunset at 5:47 pm CST.

Sunshine

In Merida, the average sunshine in September is 9.4h.

UV index

The months with the highest UV index in Merida are February through October, with an average maximum UV index of 7. A UV Index estimate of 6 to 7 represents a high threat to health from exposure to the Sun's UV radiation for average individuals.
Note: In September, a regular UV index of 7 translates into these guidelines:
Stay clear of intense sun exposure. Solar protection is of utmost significance. Limit direct sun exposure especially between 10 a.m. and 4 p.m., when UV radiation is at its peak. However, keep in mind that shade structures may not provide full sun protection. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.