Carlsbad (CA) Temperature by Month

Carlsbad, California, United States of America has a consistently pleasant climate year-round, with daytime highs averaging 21°C (70°F). Below you'll find a full monthly breakdown and a comparison with cities worldwide.

With little seasonal fluctuation, Carlsbad offers a predictable and steady climate. Maximum daytime temperatures reach a comfortable 24°C (75°F) in September and a pleasant 18°C (64°F) in December. At night, lows range from 17°C (63°F) to 7°C (45°F) throughout the year.

The chart below illustrates the average maximum day and minimum night temperatures in Carlsbad by month:

Daily lows are most common between 4 AM and 6 AM. By 3 PM temperatures reach their daily high, driven by peak solar heating. September, the warmest month of the year, receives 253 hours of sunshine.

The chart below shows the average temperature throughout the year:

Carlsbad's average annual maximum temperature is 21°C (70°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.

Toronto, Canada averages 13°C (55°F) annually, with cold snowy winters balanced by genuinely warm summers.

Osaka, Japan averages 22°C (72°F) annually, with hot humid summers, mild winters, and pleasant spring and autumn seasons.

Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.

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 Carlsbad, December is the coolest month, with average highs of 18°C (64°F) and humidity around 64%, considered high. In September, the warmest month, temperatures average 24°C (75°F) with 74% 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.

Global average temperatures have risen by around 1.2°C since the pre-industrial era, and the effects are visible across many regions. Winters are milder on average, with fewer frost days and less snow in many parts of the world. Heatwaves are more frequent and more intense, and Europe's summers of 2018, 2019, and 2020 all set records.

Summers are also getting drier in some areas, while winter rainfall has increased in others. This contributies to higher river levels and more flooding. In many countries, spring arrives earlier and autumn lasts longer. It has knock-on effects for wildlife, agriculture, and local ecosystems.

For more on Carlsbad's weather, including monthly rainfall, sunshine hours, and humidity, visit our Carlsbad climate page.