October weather forecastSunnyvale, CA
October
Weather in October
October in Sunnyvale showcases the hearty autumn season with a notable reduction of the average high temperature to 71.8°F (22.1°C). While the rainfall sees a slight increase, it remains scattered and does not significantly alter the overall weather. An increase in cloud percentage and a decrease in sunshine hours are clear signs of transitioning from the warmth of Summer to the chillier months ahead. Despite the reduced daylight, October retains enough warmth to enjoy the changing colors of Fall in all their glory.Temperature
The shift from September to October includes a minor decrease in the average high-temperature, lightly dropping from a warm 77.9°F (25.5°C) to a pleasant 71.8°F (22.1°C). In Sunnyvale, in October, the average low-temperature is a fresh 53.6°F (12°C).Humidity
The months with the lowest humidity are September and October, with an average relative humidity of 63%.Rainfall
In Sunnyvale, during October, the rain falls for 2.4 days and regularly aggregates up to 0.12" (3mm) of precipitation. Throughout the year, there are 50 rainfall days, and 3.9" (99mm) of precipitation is accumulated.Daylight
The average length of the day in October is 11h and 13min.On the first day of October, sunrise is at 7:04 am and sunset at 6:50 pm. On the last day of the month, sunrise is at 7:32 am and sunset at 6:10 pm PDT.
Sunshine
In Sunnyvale, the average sunshine in October is 7.1h.UV index
In October, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: The maximum UV index, 5 during October, leads to the following recommendations:
Guard yourself - Avoiding sunburn is suggested. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in October
Sunnyvale, CA
- Average high temperature in October: 71.8°F
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is December (56.8°F).
- Average low temperature in October: 53.6°F
The month with the highest average low temperature is August (56.8°F).
The coldest months (with the lowest average low temperature) are February and December (44.2°F).
Average pressure in October
Sunnyvale, CA
- Average pressure in October: 29.99"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June and September (29.92"Hg).
Average wind speed in October
Sunnyvale, CA
- Average wind speed in October: 4.7mph
The windiest month (with the highest average wind speed) is April (6.2mph).
The calmest month (with the lowest average wind speed) is September (4.6mph).
Average humidity in October
Sunnyvale, CA
- Average humidity in October: 63%
The month with the highest relative humidity is March (73%).
The months with the lowest relative humidity are September and October (63%).
Average rainfall in October
Sunnyvale, CA
- Average rainfall in October: 0.12"
The wettest months (with the highest rainfall) are February and March (0.75").
The driest month (with the least rainfall) is July (0").
Average rainfall days in October
Sunnyvale, CA
- Average rainfall days in October: 2.4 days
The month with the highest number of rainy days is March (9.6 days).
The month with the least rainy days is August (0.4 days).
Average daylight in October /
Average sunshine in October
Sunnyvale, CA
- Average daylight in October: 11h and 12min
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 October: 7h and 6min
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 54min).
Average sunshine days in October
Sunnyvale, CA
- Average sunshine days in October: 27.5 days
The month with the most sunshine days is August (30.1 days).
The month with the least sunshine days is March (19.9 days).
Average UV index in October
Sunnyvale, CA
- Average UV index in October: 5
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are February, November and December (UV index 3).
Average cloud cover in October
Sunnyvale, CA
- Average cloud cover in October: 16
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 7).
Average visibility in October
Sunnyvale, CA
- Average visibility in October: 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).
