September weather forecast
Compostela, Mexico

The first month of the autumn, September, is also a moderately hot month in Compostela, Mexico, with an average temperature varying between 20.4°C (68.7°F) and 29.6°C (85.3°F).

Temperature

As August transitions into September, the average high-temperature rests at a moderately hot 29.6°C (85.3°F), maintaining a close resemblance to the previous month. In the month of September, the average low-temperature usually rests at an agreeable 20.4°C (68.7°F).

Heat index

The heat index value during September is appraised at a very hot 38°C (100.4°F). Greater safety measures are needed, risk of heat exhaustion and heat cramps is high. Continuous activity might trigger heatstroke.
Remember that heat index calculations are made for conditions in the shade with light wind. Direct exposure to sunlight could raise the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', combines both the air temperature and the humidity level to give a perceived human temperature. A person's impression of weather can be affected by numerous aspects, among them metabolic variations, pregnancy, and activity levels. One must note that being under the direct sun can escalate the heat's effects, with the heat index possibly rising by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly important 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.
The body's natural response to excessive warmth is perspiration, as it allows for cooling through sweat evaporation. Augmented relative humidity impedes typical body cooling mechanisms by lowering the evaporation rate, resulting in decreased body cooling and an amplified perception of heat. The body faces dehydration threats when its cooling efforts are outpaced by excessive heat gain.

Humidity

August and September, with an average relative humidity of 86%, are the most humid months.

Rainfall

In September, the rain falls for 29 days. Throughout September, 339mm (13.35") of precipitation is accumulated. In Compostela, during the entire year, the rain falls for 164.8 days and collects up to 1589mm (62.56") of precipitation.

Daylight

The average length of the day in September in Compostela is 12h and 16min.
On the first day of September, sunrise is at 5:43 am and sunset at 6:15 pm. On the last day of the month, sunrise is at 5:50 am and sunset at 5:47 pm MST.

Sunshine

The average sunshine in September in Compostela, Mexico, is 7.5h.

UV index

February through November, with an average maximum UV index of 6, are months with the highest UV index. A UV Index reading of 6 to 7 represents a high threat to health from exposure to the Sun's UV radiation for the ordinary person.
Note: The maximum UV index of 6 during September leads to these instructions:
Fend off overexposure. Sun protection is vital. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.