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
O'Brien's transition into September involves a gentle shift in temperature, receding from a hot 90.1°F in August to a moderately hot 84°F. In September, the temperature in O'Brien, California, registers a significant dip to an average of 54.3°F at night.Heat index
The heat index value during September is estimated at 84.2°F. Constant exposure and activity lead to possible fatigue. Prolonged exercise may result in heat cramps.Data suggests that the heat index is set for environments in shade and with a light wind. Direct sunlight can cause a surge in the heat index by 15 Fahrenheit (8 Celsius) degrees.
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. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. Keep aware, the sun, when shining directly, can intensify the heat experience, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. Younglings frequently fail to recognize the requirement to rest and rehydrate. Thirst emerges late in dehydration - it is imperative to keep hydration levels high, particularly during extended physical exertions.
Humidity
In O'Brien, the average relative humidity in September is 40%.Rainfall
In O'Brien, during September, the rain falls for 3.4 days and regularly aggregates up to 0.31" of precipitation. In O'Brien, California, during the entire year, the rain falls for 102.3 days and collects up to 24.21" of precipitation.Snowfall
In O'Brien, snow does not fall in April through October.Daylight
The average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:36 am and sunset at 7:42 pm. On the last day of September, sunrise is at 7:04 am and sunset at 6:53 pm PDT.
Sunshine
In O'Brien, the average sunshine in September is 11h.UV index
In September, the average daily maximum UV index in O'Brien is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: In September, a daily maximum UV index of 5 leads to the following instructions:
Undertake precautions - It is suggested to shield oneself from sunburn. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
FAQ
How hot does it get in O'Brien in September?
What is the average humidity in September in O'Brien?
How much does it rain in O'Brien in September?
When it does not snow in O'Brien?
What is the average length of the day in September in O'Brien?
When are sunrise and sunset in September in O'Brien?
How many hours of sunshine does O'Brien have in September?
How high is the UV index in September in O'Brien?
Average temperature in September
O'Brien, CA
- Average high temperature in September: 84°F
The warmest month (with the highest average high temperature) is July (91.6°F).
The month with the lowest average high temperature is December (47.8°F).
- Average low temperature in September: 54.3°F
The month with the highest average low temperature is July (59.4°F).
The coldest month (with the lowest average low temperature) is December (33.6°F).
Average pressure in September
O'Brien, CA
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is August (29.92"Hg).
Average wind speed in September
O'Brien, CA
- Average wind speed in September: 5mph
The windiest months (with the highest average wind speed) are March and October (5.3mph).
The calmest months (with the lowest average wind speed) are August and November (4.5mph).
Average humidity in September
O'Brien, CA
- Average humidity in September: 40%
The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is August (37%).
Average rainfall in September
O'Brien, CA
- Average rainfall in September: 0.31"
The wettest month (with the highest rainfall) is March (4.8").
The driest month (with the least rainfall) is July (0.12").
Average rainfall days in September
O'Brien, CA
- Average rainfall days in September: 3.4 days
The month with the highest number of rainy days is March (16.8 days).
The month with the least rainy days is August (1.7 days).
Average snowfall in September
O'Brien, CA
- Average snowfall in September: 0"
The month with the highest snowfall is November (1.3").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
O'Brien, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.9 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
O'Brien, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 11h and 0min
The month with the most sunshine is July (Average sunshine: 12h and 12min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in September
O'Brien, CA
- Average sunshine days in September: 25.2 days
The month with the most sunshine days is August (27.1 days).
The month with the least sunshine days is March (11.8 days).
Average UV index in September
O'Brien, CA
- Average UV index in September: 5
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are February, November and December (UV index 2).
Average cloud cover in September
O'Brien, CA
- Average cloud cover in September: 9
The month with the most cloud cover is March (Cloud cover 44).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
O'Brien, CA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is December (5mi).
O'Brien, California, USA
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