Imperial Beach (CA) Temperature by Month
Imperial Beach, California, United States of America has a consistently pleasant climate year-round, with daytime highs averaging 22°C (72°F). Below you'll find a full monthly breakdown and a comparison with cities worldwide.
Imperial Beach Monthly Temperatures
Year-round, Imperial Beach experiences a consistently pleasant climate. Maximum daytime temperatures range from a comfortable 25°C (77°F) in September to a pleasant 19°C (66°F) in the coolest month, December. Nighttime temperatures range from 17°C (63°F) in September to 8°C (46°F) in December.
The chart below illustrates the average maximum day and minimum night temperatures in Imperial Beach 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. September, the city's warmest month, averages 272 hours of sunshine.
The chart below shows the average temperature throughout the year:
Temperature: Imperial Beach 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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Imperial Beach vs World: Temperature Compared
Imperial Beach's average annual maximum temperature is 22°C (72°F). To put that in context, here's how it compares to a few well-known destinations:
Barcelona, Spain has an annual average of around 21°C (70°F), with warm summers and mild, fairly short winters.
Interlaken, Switzerland averages 8°C (46°F) a year, with cold winters and cool summers thanks to its Alpine setting.
Osaka, Japan averages 22°C (72°F) annually, with hot humid summers, mild winters, and pleasant spring and autumn seasons.
Brisbane, Australia averages 26°C (79°F) a year, with warm winters and hot, humid summers.
What Does the Temperature Feel Like in Imperial Beach?
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 Imperial Beach, December is the coolest month, with average highs of 19°C (66°F) and humidity around 69% — considered high. In September, the warmest month, temperatures average 25°C (77°F) with 79% 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.
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 Imperial Beach this rarely lasts long on the ground.
For more on Imperial Beach's weather — including monthly rainfall, sunshine hours, and humidity — visit our Imperial Beach climate page.
