September weather forecast
Hermosillo, Mexico

The first month of the autumn, September, is still a torrid month in Hermosillo, Mexico, with temperature in the range of an average low of 26.2°C (79.2°F) and an average high of 35.6°C (96.1°F).

Temperature

In September, the average high-temperature is almost the same as in August - a still sweltering 35.6°C (96.1°F). In September, in Hermosillo, the average low-temperature is 26.2°C (79.2°F).

Heat index

The average heat index in September is appraised at a blistering 42°C (107.6°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel', 'feels like', 'felt air temperature', or 'apparent temperature', is calculated by taking the relative humidity value for a specific location and factoring it into the air temperature reading. Additional factors like activity, clothing, pregnancy, and metabolic differences affect individual temperature impact. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. With a lot of moisture in the air, the evaporation process is not as effective, and the body does not cool down as efficiently, creating a perception of overheating. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat-related illnesses and disorders may develop.

Humidity

In Hermosillo, the average relative humidity in September is 49%.

Rainfall

In September, in Hermosillo, Mexico, the rain falls for 11.8 days. Throughout September, 59mm (2.32") of precipitation is accumulated. In Hermosillo, during the entire year, the rain falls for 69.5 days and collects up to 262mm (10.31") of precipitation.

Daylight

In September, the average length of the day in Hermosillo is 12h and 19min.
On the first day of the month, sunrise is at 6:01 am and sunset at 6:46 pm. On the last day of September, sunrise is at 6:16 am and sunset at 6:11 pm MST.

Sunshine

In September, the average sunshine is 9.4h.

UV index

The months with the highest UV index in Hermosillo are May through September, with an average maximum UV index of 8. A UV Index of 8 to 10 symbolizes a very high health hazard from unsafe exposure to UV radiation for the average person.
Note: The average daily UV index of 8 in September transform into the following instructions:
Take extra precautions. Protection against sun damage is required. 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. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.