Lake Forest (CA) Temperature by Month

The average annual maximum temperature in Lake Forest, California, United States of America is 25°C (77°F), with daytime highs ranging from 19°C (66°F) in December to 31°C (88°F) in August. This page covers monthly averages, day-night differences, and how Lake Forest compares to cities worldwide.

The climate in Lake Forest is known for significant temperature differences throughout the year. At night, this contrast is just as clear, with lows ranging from 16°C (61°F) in August to 8°C (46°F) in December.

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

From around 4 AM to 6 AM temperatures are at their lowest; by 3 PM they've climbed to their daily peak. August, the warmest month, averages 351 hours of sunshine.

The chart below shows the average temperature throughout the year:

Lake Forest's average annual maximum temperature is 25°C (77°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.

Glasgow, Scotland averages 13°C (55°F) a year, mild but often grey, with cold winters and rarely hot summers.

San Francisco, USA averages 19°C (66°F) annually, but with little seasonal variation, summers are often cool and foggy, winters mild.

Tokyo, Japan averages 21°C (70°F) a year, with hot summers, cool winters, and a well-defined cherry blossom spring.

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 Lake Forest's weather, including monthly rainfall, sunshine hours, and humidity, visit our Lake Forest climate page.