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 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
In Modesto, the average high-temperature in September marginally drops from a very hot 96.4°F (35.8°C) in August to a hot 90.9°F (32.7°C). In Modesto, California, the average low-temperature is 59.9°F (15.5°C).Heat index
In September, the average heat index is appraised at a hot 93.2°F (34°C). 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', 'apparent temperature', or 'felt air temperature', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. Additional factors like activity, pregnancy, wind, and differences in body mass, height, and shape affect individual temperature impact. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.
Humidity
In September, the average relative humidity is 41%.Rainfall
In Modesto, during September, the rain falls for 1.6 days and regularly aggregates up to 0.08" (2mm) of precipitation. Throughout the year, there are 54.3 rainfall days, and 6.54" (166mm) of precipitation is accumulated.Daylight
In September, the average length of the day in Modesto is 12h and 25min.On the first day of the month, sunrise is at 6:34 am and sunset at 7:33 pm. On the last day of September, in Modesto, California, sunrise is at 6:58 am and sunset at 6:49 pm PDT.
Sunshine
The average sunshine in September in Modesto is 11.5h.UV index
The average daily maximum UV index in September in Modesto is 6. A UV Index reading of 6 to 7 represents a high health vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: In September, the average maximum UV index of 6 translate into the following recommendations:
Take precautions against overexposure. Protection against sun damage is needed. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. 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.
FAQ
What is the temperature in September in Modesto?
What is the average humidity in September in Modesto?
How many days does it rain in September in Modesto?
How many hours of daylight does Modesto have in September?
When is the sunrise / sunset in September in Modesto?
How long on average sun shines in September in Modesto?
What is the UV index intensity in September in Modesto?
Average temperature in September
Modesto, CA
- Average high temperature in September: 90.9°F
The warmest month (with the highest average high temperature) is July (97.7°F).
The month with the lowest average high temperature is December (55.6°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (62.1°F).
The coldest months (with the lowest average low temperature) are January and December (41.9°F).
Average pressure in September
Modesto, CA
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Modesto, CA
- Average wind speed in September: 5.8mph
The windiest month (with the highest average wind speed) is June (7.3mph).
The calmest month (with the lowest average wind speed) is November (5.2mph).
Average humidity in September
Modesto, CA
- Average humidity in September: 41%
The month with the highest relative humidity is January (72%).
The month with the lowest relative humidity is July (37%).
Average rainfall in September
Modesto, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is March (1.3").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Modesto, CA
- Average rainfall days in September: 1.6 days
The month with the highest number of rainy days is March (10.3 days).
The month with the least rainy days is August (0.9 days).
Average daylight in September /
Average sunshine in September
Modesto, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in September: 11h and 3min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 0min).
Average sunshine days in September
Modesto, CA
- Average sunshine days in September: 27.1 days
The month with the most sunshine days is August (29.2 days).
The month with the least sunshine days is March (19.6 days).
Average UV index in September
Modesto, CA
- Average UV index in September: 6
The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
Modesto, CA
- Average cloud cover in September: 6
The month with the most cloud cover is March (Cloud cover 33).
The month with the least cloud cover is July (Cloud cover 4).
Average visibility in September
Modesto, CA
- 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).
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