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
Los Altos Hills, California, registers an average high-temperature of a still pleasant 72.5°F (22.5°C) at the commencement of September, closely related to the preceding month. During September, Los Altos Hills experiences a consistent low-temperature average of 56.7°F (13.7°C).Humidity
In Los Altos Hills, the average relative humidity in September is 71%.Rainfall
In Los Altos Hills, in September, during 2.4 rainfall days, 0.08" (2mm) of precipitation is typically accumulated. In Los Altos Hills, during the entire year, the rain falls for 57.5 days and collects up to 4.76" (121mm) of precipitation.Daylight
In September, the average length of the day is 12h and 25min.On the first day of the month, sunrise is at 6:39 am and sunset at 7:36 pm. On the last day of September, sunrise is at 7:03 am and sunset at 6:52 pm PDT.
Sunshine
In September, the average sunshine is 11h.UV index
June through September, with an average maximum UV index of 5, are months with the highest UV index. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the ordinary person.Note: The average daily UV index of 5 in September transforms into the following instructions:
Guard yourself - Precautionary measures against sun damage are advocated. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
How many days does it rain in September?
How many hours of daylight does Los Altos Hills have in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
What is the month with the highest UV index?
What is the UV index intensity in September?
Average temperature in September
Los Altos Hills, CA
- Average high temperature in September: 72.5°F
The warmest month (with the highest average high temperature) is August (73°F).
The month with the lowest average high temperature is December (55.8°F).
- Average low temperature in September: 56.7°F
The months with the highest average low temperature are August and September (56.7°F).
The coldest months (with the lowest average low temperature) are January and February (46.4°F).
Average pressure in September
Los Altos Hills, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.92"Hg).
Average wind speed in September
Los Altos Hills, CA
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is April (7.6mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).
Average humidity in September
Los Altos Hills, CA
- Average humidity in September: 71%
The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is October (68%).
Average rainfall in September
Los Altos Hills, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is February (0.98").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Los Altos Hills, CA
- Average rainfall days in September: 2.4 days
The month with the highest number of rainy days is March (10.6 days).
The month with the least rainy days is June (0.9 days).
Average daylight in September /
Average sunshine in September
Los Altos Hills, 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 0min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).
Average sunshine days in September
Los Altos Hills, CA
- Average sunshine days in September: 25.8 days
The months with the most sunshine days are June and July (26.3 days).
The month with the least sunshine days is March (18.3 days).
Average UV index in September
Los Altos Hills, CA
- Average UV index in September: 5
The months with the highest UV index are June, July, August and September (UV index 5).
The months with the lowest UV index are February, November and December (UV index 3).
Average cloud cover in September
Los Altos Hills, CA
- Average cloud cover in September: 12
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in September
Los Altos Hills, 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).
Los Altos Hills, California, USA
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