Pasadena (CA) Temperature by Month
Pasadena in California, United States of America sees significant seasonal temperature differences, with daytime highs between 20°C (68°F) in December and 33°C (91°F) in August, averaging 26°C (79°F) annually. Explore the full monthly breakdown below.
Pasadena Monthly Temperatures
In Pasadena, temperatures can shift dramatically between very warm in summer and pleasant in winter. Nights follow the same pattern, with lows ranging from 18°C (64°F) in August to 8°C (46°F) in December.
The chart below illustrates the average maximum day and minimum night temperatures in Pasadena by month:
The coolest part of the day is typically between 4 AM and 6 AM, while 3 PM is usually the warmest, when solar heating is at its peak. August, the city's warmest month, averages 347 hours of sunshine.
The chart below shows the average temperature throughout the year:
Temperature: Pasadena 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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Pasadena vs World: Temperature Compared
Pasadena's average annual maximum temperature is 26°C (79°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.
Zermatt, Switzerland averages just 4°C (39°F) annually due to its altitude, with very cold winters and cool summers even at its warmest.
Seoul, South Korea averages 18°C (64°F) a year, with four clear seasons, cold winters, and hot humid summers.
Melbourne, Australia averages 20°C (68°F) annually — known for unpredictable weather, with four seasons sometimes happening in one day.
What Does the Temperature Feel Like in Pasadena?
Temperature alone doesn't tell the whole story — humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.
In Pasadena, December is the coolest month, with average highs of 20°C (68°F) and humidity around 52% — considered moderate. In August, the warmest month, temperatures average 33°C (91°F) with 71% humidity — conditions that feel high. For a full picture, see our humidity page.
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.
For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained — so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.
For more on Pasadena's weather — including monthly rainfall, sunshine hours, and humidity — visit our Pasadena climate page.
