San Clemente (CA) Temperature by Month
San Clemente in California, United States of America sees moderate seasonal temperature shifts, with daytime highs between 19°C (66°F) in December and 27°C (81°F) in September, averaging 23°C (73°F) annually. Explore the full monthly breakdown below.
San Clemente Monthly Temperatures
Seasonal changes in San Clemente bring a little variety without extreme temperature swings. Nighttime lows range from 16°C (61°F) in September to 8°C (46°F) in December.
The chart below illustrates the average maximum day and minimum night temperatures in San Clemente by month:
The coldest point of the day usually falls between 4 AM and 6 AM, with temperatures peaking around 3 PM. September, the city's warmest month, gets 290 hours of sunshine.
The chart below shows the average temperature throughout the year:
Temperature: San Clemente vs the United States of America
The map below shows the annual temperature across the United States of America. You can also select individual months if you want to compare a specific time of year.
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San Clemente vs World: Temperature Compared
San Clemente's average annual maximum temperature is 23°C (73°F). To put that in context, here's how it compares to a few well-known destinations:
Rome, Italy averages 20°C (68°F) annually, with reliably warm summers and comfortable winters.
Queenstown, New Zealand averages 10°C (50°F) annually — remember seasons are flipped, so its coldest months fall in June and July.
Buenos Aires, Argentina averages 23°C (73°F) a year, with hot summers and mild winters — and seasons reversed compared to Europe.
Melbourne, Australia averages 20°C (68°F) annually — known for unpredictable weather, with four seasons sometimes happening in one day.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
Seasonal temperature shifts influence more than just how warm it feels — they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.
Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in San Clemente this rarely lasts long on the ground.
For more on San Clemente's weather — including monthly rainfall, sunshine hours, and humidity — visit our San Clemente climate page.
