Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The start of September signals a gentle decrease in the average high-temperature, transitioning from a fiery hot 98.2°F (36.8°C) in August to a hot 92.5°F (33.6°C). San Juan, in September, witnesses an average low-temperature of 77.2°F (25.1°C).Heat index
The heat index for September is calculated to be a blisteringly hot 109.4°F (43°C). Be careful: Heat exhaustion and heat cramps are probable. Heatstroke may result from extended activity.Regarding the heat index, one should be aware it's determined by shaded settings and mild winds. With direct sunlight, the heat index could increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', comes about by integrating the temperature readings with the humidity levels. The perception of temperature can be subjective, varying based on activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. It is noteworthy to mention that direct sunlight exposure can augment the felt temperature, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Youngsters generally face more threats than adults given their lesser ability to sweat. Coupled with their larger skin surface relative to their small bodies and higher heat production due to their activities, they are more endangered.
The human body normally cools itself by perspiration, as evaporated sweat carries heat away from the body. High relative humidity reduces the evaporation rate, resulting in a lower heat removal rate from the body, causing the perception of being overheated. Overheating dangers loom when the body's heat release mechanisms are overshadowed by excessive gain.
Humidity
The average relative humidity in September is 65%.Rainfall
The month with the most rainfall is September, when the rain falls for 15.1 days and typically aggregates up to 1.46" (37mm) of precipitation.Snowfall
In San Juan, Texas, snow does not fall in February through December.Daylight
In San Juan, the average length of the day in September is 12h and 18min.On the first day of the month, sunrise is at 7:12 am and sunset at 7:51 pm. On the last day of September, in San Juan, Texas, sunrise is at 7:24 am and sunset at 7:19 pm CDT.
Sunshine
The average sunshine in September in San Juan is 8.6h.UV index
In September, the average daily maximum UV index is 7. A UV Index of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for the ordinary person.Note: A maximum UV index of 7 in September translates into the following recommendations:
Apply measures and align with sun safety principles. Safeguarding against skin and eye injury is pivotal. Minimize exposure to direct sunlight and seek shade from 10 a.m. to 4 p.m., when UV radiation is most intense, but remember that shade structures may not offer complete protection. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Frequently asked questions
How hot is it in San Juan in September?
What is the average humidity in September in San Juan?
What is the rainiest month in San Juan?
How much does it rain in San Juan in September?
When it does not snow in San Juan?
How many hours of daylight does San Juan have in September?
When are sunrise and sunset in September in San Juan?
How many hours of sunshine does San Juan have in September?
How high is the UV index in September in San Juan?
Average temperature in September
San Juan, TX
- Average high temperature in September: 92.5°F
The warmest month (with the highest average high temperature) is August (98.2°F).
The month with the lowest average high temperature is January (69.6°F).
- Average low temperature in September: 77.2°F
The month with the highest average low temperature is August (79.7°F).
The coldest month (with the lowest average low temperature) is January (53.4°F).
Average pressure in September
San Juan, TX
- Average pressure in September: 29.91"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The months with the lowest atmospheric pressure are May and June (29.87"Hg).
Average wind speed in September
San Juan, TX
- Average wind speed in September: 8.9mph
The windiest month (with the highest average wind speed) is May (12.4mph).
The calmest month (with the lowest average wind speed) is September (8.9mph).
Average humidity in September
San Juan, TX
- Average humidity in September: 65%
The month with the highest relative humidity is May (69%).
The month with the lowest relative humidity is August (59%).
Average rainfall in September
San Juan, TX
- Average rainfall in September: 1.46"
The wettest month (with the highest rainfall) is September (1.46").
The driest months (with the least rainfall) are January and February (0.31").
Average rainfall days in September
San Juan, TX
- Average rainfall days in September: 15.1 days
The month with the highest number of rainy days is September (15.1 days).
The month with the least rainy days is February (5.4 days).
Average snowfall in September
San Juan, TX
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.12").
The months with the least snowfall are February, March, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
San Juan, TX
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.1 days).
The months with the least snowfall days are February, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
San Juan, TX
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 13h and 48min).
The month with the shortest days is December (Average daylight: 10h and 30min).
- Average sunshine in September: 8h and 4min
The month with the most sunshine is July (Average sunshine: 11h and 24min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).
Average sunshine days in September
San Juan, TX
- Average sunshine days in September: 12.5 days
The month with the most sunshine days is July (23 days).
The month with the least sunshine days is September (12.5 days).
Average UV index in September
San Juan, TX
- Average UV index in September: 7
The months with the highest UV index are July and August (UV index 8).
The month with the lowest UV index is December (UV index 4).
Average cloud cover in September
San Juan, TX
- Average cloud cover in September: 30
The month with the most cloud cover is December (Cloud cover 39).
The month with the least cloud cover is August (Cloud cover 18).
Average visibility in September
San Juan, TX
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
San Juan, Texas, USA
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