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
The commencement of September includes a gentle temperature shift, with the average high-temperature dropping a bit from a torrid 96.4°F (35.8°C) in August to a tropical 90.9°F (32.7°C). Contrasting the daytime warmth, Modesto's September nights cool down to an average of 59.9°F (15.5°C).Heat index
September's heat index is calculated to be a tropical 93.2°F (34°C). Take greater precautions, heat exhaustion and heat cramps may be expected. Heatstroke could result from lengthy activity.For clarity, heat index numbers account for light winds and areas under shade. Heat index values may rise by up to 15 Fahrenheit (8 Celsius) degrees when exposed to direct sunlight.
Note: The heat index, also known as 'feels like' or 'apparent temperature', stands as a testimony to how temperature and humidity combine to impact our sense of warmth. Elements of metabolic variation, physical activity, and clothing contribute to the effect of temperature on an individual. Understand that direct sun rays can influence the weather's impact, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Children regularly disregard the necessity to rest and replenish fluids. Thirst is a late symptom of dehydration - thus, maintaining hydration, particularly during long-lasting physical activities, is essential.
Humidity
The average relative humidity in September in Modesto is 41%.Rainfall
In Modesto, during September, the rain falls for 1.6 days and regularly aggregates up to 0.08" (2mm) of precipitation. In Modesto, California, during the entire year, the rain falls for 54.3 days and collects up to 6.54" (166mm) of precipitation.Daylight
In September, the average length of the day in Modesto is 12h and 25min.On the first day of September, sunrise is at 6:34 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:59 am and sunset at 6:48 pm PDT.
Sunshine
In Modesto, the average sunshine in September is 11.5h.UV index
In September, the average daily maximum UV index in Modesto is 6. A UV Index value of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for the ordinary person.Note: A maximum UV index of 6 in September translates into the following recommendations:
Steer clear of overexposure. Fair-skinned individuals can be scorched in less than 20 minutes. Attempt to stay under shade and limit exposure to the Sun between 10 a.m. and 4 p.m., when UV radiation is at its peak. Remember, devices such as parasols or canopies might not provide complete sun protection. Employ a wide-brim hat for potent defense against up to 50% of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is it in Modesto in September?
What is the average humidity in September in Modesto?
How much does it rain in Modesto in September?
What is the average length of the day in September in Modesto?
What time are sunrise and sunset in September in Modesto?
How long on average sun shines in September in Modesto?
What is the UV index reading 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).
Modesto, California, USA
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