San Mateo (CA) Temperatures: Monthly Averages and Year-Round Insights
On this page, we’ll explore San Mateo’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
In San Mateo, seasonal changes bring about a moderate variation in temperatures. Average maximum daytime temperatures range from a comfortable 24°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 6°C during these months.
The chart below illustrates the average maximum day and minimum night temperatures in San Mateo 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 63 mm of rainfall spread over roughly 9 days. For more information, please visit our San Mateo 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.
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San Mateo Temperatures Compared World Wide
San Mateo’s average annual maximum temperature is 20°C. Let’s compare this with some popular tourist destinations:
Athens, Greece, experiences an average annual temperature of 23°C, with hot summers and mild winters typical of a Mediterranean climate.
In contrast, in ReykjavÃk, Iceland, the average annual temperature is significantly lower at 9°C, with mild summers and cold winters.
In Seoul, South Korea, the average annual temperature is 18°C, featuring distinct seasons.
Adelaide, Australia, enjoys warm summers and mild winters, with an average annual temperature of 21°C.
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 San Mateo, during the coolest month, January, you will experience 80% humidity, which is considered very high. This is accompanied by an average maximum temperature of 15°C. In the warmest month, September, the humidity is 73% combined with an average maximum temperature of 24°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 San Mateo’s weather, including monthly rainfall, sunshine hours, and humidity levels, visit our San Mateo climate page.
Current temperature in San Mateo (CA)
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