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October Weather in Sunnyvale, United States

Last updated: June 24, 2025

In October, the average temperature in Sunnyvale, United States hovers around 17°C (63°F), making it a comfortable time of year. Temperatures can dip as low as 5°C (42°F) or soar up to 34°C (94°F), so a variety of clothing options might be wise. Expect 25 mm (1.0 in) of rainfall spread over about 1 day, adding a touch of freshness to the air. With an average humidity of 62%, the climate is pleasantly mild, ensuring a delightful experience for residents and visitors alike.

October Temperature in Sunnyvale

In October in Sunnyvale, the average temperature is 17°C (63°F), with maximums reaching 34°C (94°F) and minimums dropping as low as 5°C (42°F). This range of temperatures makes Sunnyvale an ideal destination for travelers seeking both warm days and cooler evenings.

October Weather in Sunnyvale: Daily Temperature Highs, Lows, and Averages

The chart illustrates October temperature patterns in Sunnyvale, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Sunnyvale, October typically has an average temperature of 17°C (63°F), with highs reaching up to 34°C (94°F) and lows dropping to around 5°C (42°F).
JanFebMarAprMayJunJulAugSepOctNovDec505153565964666766635550
Data source: Temperature data for Sunnyvale generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

October Precipitation in Sunnyvale

In Sunnyvale in October, the precipitation amount is 25 mm (1.0 in) over the course of 1 day.

October Precipitation Trends in Sunnyvale

The chart displays monthly precipitation patterns in Sunnyvale, with values for each month alongside October’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how October’s conditions compare to those of other months. In Sunnyvale, October typically receives around 25 mm (1.0 inches) of precipitation spread over approximately 1 days.
JanFebMarAprMayJunJulAugSepOctNovDec145133114372410132556116
Data source: Precipitation data for October generated using information from the Copernicus Climate Change Service.
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October Humidity in Sunnyvale

In Sunnyvale in October humidity is 62%. With an average temperature of 17°C (63°F), this humidity feels like a refreshing embrace, making it pleasant for traveling as long as you stay hydrated and take breaks in the shade.

October Average Humidity in Sunnyvale

This chart illustrates the average monthly humidity levels in Sunnyvale, with October’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In October, average humidity in Sunnyvale is approximately 62%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec82%84%82%78%71%64%59%54%55%62%78%80%
Data source: Humidity data for October generated using information from the Copernicus Climate Change Service.

October UV Index in Sunnyvale

In Sunnyvale in October, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Sunnyvale.

Maximum UV Index Levels in Sunnyvale for October

The chart shows the monthly maximum UV Index (UVI) for Sunnyvale in October, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In October, the maximum UV index in Sunnyvale typically reaches 7, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec4589111111109753
Data source: Sunnyvale October UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How October Weather in Sunnyvale Compares to Other Months

Weather in Sunnyvale varies notably across the year, with each month offering distinct climate conditions. This page compares October’s weather to other months in Sunnyvale, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Sunnyvale, showing how October’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather10°C (51°F)145 mm (5.7 inches)82%moderate
February Weather11°C (52°F)133 mm (5.2 inches)84%moderate
March Weather11°C (53°F)114 mm (4.5 inches)82%very high
April Weather13°C (56°F)37 mm (1.4 inches)78%very high
May Weather15°C (59°F)24 mm (0.9 inches)71%extreme
June Weather18°C (64°F)1 mm (0.0 inches)64%extreme
July Weather19°C (66°F)0 mm (0.0 inches)58%extreme
August Weather19°C (67°F)0 mm (0.0 inches)54%very high
September Weather19°C (67°F)3 mm (0.1 inches)55%very high
October Weather17°C (63°F)25 mm (1.0 inches)62%high
November Weather13°C (56°F)56 mm (2.2 inches)78%moderate
December Weather10°C (50°F)116 mm (4.6 inches)80%moderate

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