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 September, Pleasanton experiences a minor shift in meteorological conditions with average high-temperatures marked at a still warm 82°F (27.8°C), closely mirroring the climate in August. Despite higher daytime temperatures, nighttime averages fall to a moderate 56.3°F (13.5°C) in September in Pleasanton, California.Heat index
September's mean heat index is evaluated at 84.2°F (29°C). Constant exposure and activity lead to possible fatigue. Prolonged exercise may result in heat cramps.Heat index's context suggests values are appropriate for shady areas and slight breezes. A rise of up to 15 Fahrenheit (8 Celsius) degrees in the heat index could result from direct sunlight.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is a calculation that merges air temperature and relative humidity to depict the sensation 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. Realize that direct exposure to sunlight can augment the felt heat, leading to a potential increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to children. Children often overlook the necessity for resting and fluid replenishment. Thirst is a late sign of dehydration - thus, it is critical to stay hydrated, especially during extended periods of physical activities.
Humidity
The months with the lowest humidity in Pleasanton, California, are July and September, with an average relative humidity of 56%.Rainfall
In September, the rain falls for 2.3 days. Throughout September, 0.12" (3mm) of precipitation is accumulated. Throughout the year, there are 70.2 rainfall days, and 10.98" (279mm) of precipitation is accumulated.Daylight
In Pleasanton, California, the average length of the day in September is 12h and 25min.On the first day of September, sunrise is at 6:38 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:51 pm PDT.
Sunshine
In Pleasanton, the average sunshine in September is 11.2h.UV index
In Pleasanton, California, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for average individuals.Note: In September, the maximum UV index of 5 suggests this advice:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What are the least humid months?
What is the average humidity in September?
How many days does it rain in September?
What is the average length of the day in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Pleasanton, CA
- Average high temperature in September: 82°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is December (55°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is August (56.7°F).
The coldest month (with the lowest average low temperature) is January (41.5°F).
Average pressure in September
Pleasanton, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in September
Pleasanton, CA
- Average wind speed in September: 5mph
The windiest month (with the highest average wind speed) is May (6.3mph).
The calmest month (with the lowest average wind speed) is November (4.2mph).
Average humidity in September
Pleasanton, CA
- Average humidity in September: 56%
The month with the highest relative humidity is March (74%).
The months with the lowest relative humidity are July and September (56%).
Average rainfall in September
Pleasanton, CA
- Average rainfall in September: 0.12"
The wettest month (with the highest rainfall) is February (2.05").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Pleasanton, CA
- Average rainfall days in September: 2.3 days
The month with the highest number of rainy days is March (12.4 days).
The month with the least rainy days is August (0.9 days).
Average daylight in September /
Average sunshine in September
Pleasanton, 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 1min
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
Pleasanton, CA
- Average sunshine days in September: 27 days
The month with the most sunshine days is August (29 days).
The month with the least sunshine days is March (17.6 days).
Average UV index in September
Pleasanton, CA
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
Pleasanton, CA
- Average cloud cover in September: 9
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 5).
Average visibility in September
Pleasanton, 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).
Pleasanton, California, USA
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