Sunnyvale (CA) Temperatures: Monthly Averages and Year-Round Insights
On this page, we’ll explore Sunnyvale’s temperature statistics in detail, including day and night variations and monthly averages. We’ll also compare the annual temperature to other cities in the United States of America.
Monthly Temperature Averages
The climate in Sunnyvale is dynamic, ranging widely from moderate in winter to comfortable in summer. Average maximum daytime temperatures range from a comfortable 27°C in September, the warmest time of the year, to a moderate 15°C during cooler months like January. At night, minimum temperatures typically average around 5°C during these months.
The chart below illustrates the average maximum day and minimum night temperatures in Sunnyvale by month:
The minimum temperature is often recorded between 4 AM and 6 AM, while the highest temperature is usually reached at 3 PM. During this time the sun's heating effect is the strongest. September, the city’s warmest month receives 270 hours of sunshine.
The chart below shows the average temperature throughout the year:
January, the city’s coldest month, receives about 54 mm of rainfall spread over roughly 8 days. For more information, please visit our Sunnyvale Precipitation page.
Annual Temperatures in the United States of America Compared
The map below shows the annual temperature across the United States of America. You can also select the different months in case you are interested in a specific month.
very warm
warm
pleasant
moderate
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Sunnyvale Temperatures Compared World Wide
Sunnyvale’s average annual maximum temperature is 21°C. Let’s compare this with some popular tourist destinations:
The city of Rome, Italy, has an average annual temperature of 20°C, known for its sunny summers and comfortable winters.
In contrast, in Oslo, Norway, the average annual temperature is significantly lower at 10°C, with mild summers and cold winters.
Meanwhile, New York City, USA, experiences a more pronounced seasonal variation with an average annual temperature of 17°C.
In Brisbane, Australia, the average annual temperature is 26°C, making it warmer than Sydney.
How does the temperature feel?
Humidity is an essential factor in how you experience temperature. When a warm period is accompanied by high humidity, it results in a higher perceived temperature. This is especially true when temperatures exceed 25°C, as it can cause greater discomfort.
In Sunnyvale, during the coolest month, January, you will experience 80% humidity, which is considered very high. This is accompanied by an average maximum temperature of 16°C. In the warmest month, September, the humidity is 73% combined with an average maximum temperature of 27°C, which creates a high-feel temperature. Explore our detailed page on humidity levels for further details.
How are these Temperatures Measured?
Generally, temperature data depicting climate is usually given over a 30-year average in order to reduce short-term fluctuations and reveal better long-term trends in climate conditions.
This temperature data is taken from land-based thermometers, ocean buoys, ships, and satellites. These measurements are transmitted to weather stations and climate centers around the globe where they are processed, averaged, and analyzed in order to monitor the trends and create climate models.
Temperatures in the Mountains
Although not all regions have mountains, elevated areas exhibit distinct temperature variations.
- Sun Exposure: Sunlit slopes tend to be warmer, while shaded areas remain cooler.
- Altitude Effects: Temperatures drop by approximately 6°C for every 1,000 meters of elevation, creating distinct microclimates.
For more detailed information about Sunnyvale’s weather, including monthly rainfall, sunshine hours, and humidity levels, visit our Sunnyvale climate page.
Current temperature in Sunnyvale (CA)
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