September weather forecastChelem, Mexico
September
Weather in September
The first month of the autumn, September, is still a hot month in Chelem, Mexico, with an average temperature varying between 25.7°C (78.3°F) and 30.5°C (86.9°F).Temperature
The transition from August to September brings an average high-temperature of a still tropical 30.5°C (86.9°F), barely different from August's 31.1°C (88°F). An average low-temperature of 25.7°C (78.3°F) characterizes Chelem's September nights.Heat index
The heat index value during September is computed to be a sweltering 39°C (102.2°F). Adopt heightened safety measures, heat cramps and heat exhaustion may occur. Sustained activity might cause heatstroke.It is crucial to understand that heat index figures are for shade and gentle wind conditions. Direct sunlight exposure may result in a rise of the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', unifies temperature and humidity readings to offer a comprehensive feel of warmth. This impact is subjective, influenced by the person's physical activity and individual heat perception, affected by factors including wind, attire, and metabolic differences. Under direct sun rays, the felt temperature might be heightened, with the heat index increasing by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Young individuals are typically more threatened than adults due to their reduced perspiration. Also, the larger skin surface proportionate to their small bodies and the increased heat from their activities magnify their risk.
Normally, the human body cools itself through perspiration, which removes excessive heat by evaporating sweat. Higher relative humidity impedes evaporation, thus reducing heat dispersion from the body, culminating in a sensation of overheating. When the body is unable to balance heat gain, its temperature elevates, which may induce thermal illnesses.
Humidity
With an average relative humidity of 78%, September is the most humid month.Rainfall
In Chelem, in September, it is raining for 19.8 days, with typically 69mm (2.72") of accumulated precipitation. In Chelem, during the entire year, the rain falls for 165.2 days and collects up to 489mm (19.25") of precipitation.Daylight
The average length of the day in September is 12h and 16min.On the first day of September, sunrise is at 5:42 am and sunset at 6:14 pm. On the last day of the month, sunrise is at 5:50 am and sunset at 5:47 pm CST.
Sunshine
In September, the average sunshine is 10.3h.UV index
The months with the highest UV index are March through October, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high threat to health from unsafe exposure to UV radiation for average individuals.Note: A daily high UV index of 7 in September leads to these guidelines:
Guard against overexposure. Protection from sun-induced harm is essential. Avoid direct Sun exposure from 10 a.m. to 4 p.m., a period when UV radiation is most intense, and remember that not all shade structures provide full protection. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Chelem, Mexico
- Average high temperature in September: 30.5°C
The warmest month (with the highest average high temperature) is August (31.1°C).
The month with the lowest average high temperature is January (25.3°C).
- Average low temperature in September: 25.7°C
The month with the highest average low temperature is August (26°C).
The coldest month (with the lowest average low temperature) is January (21°C).
Average pressure in September
Chelem, Mexico
- Average pressure in September: 1011.9mbar
The month with the highest atmospheric pressure is January (1017.8mbar).
The month with the lowest atmospheric pressure is September (1011.9mbar).
Average wind speed in September
Chelem, Mexico
- Average wind speed in September: 17km/h
The windiest month (with the highest average wind speed) is March (23.1km/h).
The calmest month (with the lowest average wind speed) is September (17km/h).
Average humidity in September
Chelem, Mexico
- Average humidity in September: 78%
The month with the highest relative humidity is September (78%).
The month with the lowest relative humidity is March (72%).
Average rainfall in September
Chelem, Mexico
- Average rainfall in September: 69mm
The wettest month (with the highest rainfall) is June (81mm).
The driest months (with the least rainfall) are February and March (12mm).
Average rainfall days in September
Chelem, Mexico
- Average rainfall days in September: 19.8 days
The month with the highest number of rainy days is September (19.8 days).
The month with the least rainy days is March (7.5 days).
Average daylight in September /
Average sunshine in September
Chelem, Mexico
- Average daylight in September: 12h and 18min
The month with the longest days is June (Average daylight: 13h and 24min).
The month with the shortest days is December (Average daylight: 10h and 54min).
- Average sunshine in September: 10h and 18min
The month with the most sunshine is July (Average sunshine: 11h and 42min).
The month with the least sunshine is January (Average sunshine: 6h and 24min).
Average sunshine days in September
Chelem, Mexico
- Average sunshine days in September: 7.2 days
The month with the most sunshine days is March (21.4 days).
The month with the least sunshine days is September (7.2 days).
Average UV index in September
Chelem, Mexico
- Average UV index in September: 7
The months with the highest UV index are March, April, May, June, July, August, September and October (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 6).
Average cloud cover in September
Chelem, Mexico
- Average cloud cover in September: 26
The month with the most cloud cover is January (Cloud cover 32).
The month with the least cloud cover is July (Cloud cover 18).
Average visibility in September
Chelem, Mexico
- Average visibility in September: 10km
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).





