September weather forecastDiscovery Bay, CA
September
Weather in September
September, the first month of the autumn in Discovery Bay, is also a moderately hot month, with an average temperature ranging between max 85.3°F (29.6°C) and min 57.7°F (14.3°C).Temperature
In September, Discovery Bay experiences a minor shift in meteorological conditions with average high-temperatures marked at a moderately hot 85.3°F (29.6°C), closely mirroring the climate in August. The nighttime average for Discovery Bay in September plummets considerably from its daytime counterpart, resting at a mild 57.7°F (14.3°C).Heat index
The heat index for September is evaluated at a tropical 87.8°F (31°C). If one sustains activity during exposure, it could lead to a sense of fatigue, with a chance of heat cramps.It is worth noting that heat index values are gauged for conditions in the shade and light breezes. Heat index values can rise by 15 Fahrenheit (8 Celsius) degrees when in direct sunlight.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is an estimation of the warmth sensation when considering humidity levels. Factors encompassing physical activity, clothing, and metabolic differences have a role in shaping the individual's impression of temperature. Remember, direct sunlight exposure can heighten the heat impact and might increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Kids frequently fail to realize the necessity for resting and hydrating. Thirst is an advanced indication of dehydration - hence, maintaining hydration, especially during extended physical activities, becomes essential.
Humidity
September is the least humid month, with an average relative humidity of 52%.Rainfall
In Discovery Bay, during September, the rain falls for 1.3 days and regularly aggregates up to 0.08" (2mm) of precipitation. In Discovery Bay, during the entire year, the rain falls for 62 days and collects up to 10.16" (258mm) of precipitation.Snowfall
January through November are months without snowfall.Daylight
In September, the average length of the day is 12h and 25min.On the first day of September, sunrise is at 6:37 am and sunset at 7:35 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:50 pm PDT.
Sunshine
In Discovery Bay, the average sunshine in September is 11.2h.UV index
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 exposure to the Sun's UV radiation for the average person.Note: The daily high UV index of 5 during September translates into the following recommendations:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Discovery Bay, CA
- Average high temperature in September: 85.3°F
The warmest month (with the highest average high temperature) is July (88.5°F).
The month with the lowest average high temperature is December (55°F).
- Average low temperature in September: 57.7°F
The month with the highest average low temperature is September (57.7°F).
The coldest month (with the lowest average low temperature) is January (41.5°F).
Average pressure in September
Discovery Bay, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Discovery Bay, CA
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is June (7.8mph).
The calmest months (with the lowest average wind speed) are January and November (4.5mph).
Average humidity in September
Discovery Bay, CA
- Average humidity in September: 52%
The month with the highest relative humidity is January (74%).
The month with the lowest relative humidity is September (52%).
Average rainfall in September
Discovery Bay, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is February (2.09").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Discovery Bay, CA
- Average rainfall days in September: 1.3 days
The month with the highest number of rainy days is March (12.3 days).
The month with the least rainy days is August (0.8 days).
Average snowfall days in September
Discovery Bay, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
Discovery Bay, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in September: 11h and 12min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days in September
Discovery Bay, CA
- Average sunshine days in September: 28.5 days
The month with the most sunshine days is August (29.8 days).
The month with the least sunshine days is March (17.7 days).
Average UV index in September
Discovery Bay, 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
Discovery Bay, CA
- Average cloud cover in September: 8
The months with the most cloud cover are March and December (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 5).
Average visibility in September
Discovery Bay, 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).
