Guerneville (CA) Temperature by Month
The average annual maximum temperature in Guerneville, California, United States of America is 22°C (72°F), with daytime highs ranging from 14°C (57°F) in December to 28°C (82°F) in July. This page covers monthly averages, day-night differences, and how Guerneville compares to cities worldwide.
Guerneville Monthly Temperatures
The climate in Guerneville is dynamic, ranging widely from moderate in winter to comfortable in summer. Nights are significantly colder, with lows dropping from 11°C (52°F) in July to 3°C (37°F) in December.
The chart below illustrates the average maximum day and minimum night temperatures in Guerneville by month:
The coldest point of the day usually falls between 4 AM and 6 AM, with temperatures peaking around 3 PM. July, the city's warmest month, gets 306 hours of sunshine.
The chart below shows the average temperature throughout the year:
Temperature: Guerneville 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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Guerneville vs World: Temperature Compared
Guerneville'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:
Lisbon, Portugal averages 21°C (70°F) annually — warm summers, mild winters, and rain mainly in the cooler months.
Queenstown, New Zealand averages 10°C (50°F) annually — remember seasons are flipped, so its coldest months fall in June and July.
San Francisco, USA averages 19°C (66°F) annually, but with little seasonal variation — summers are often cool and foggy, winters mild.
Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.
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 Guerneville's weather — including monthly rainfall, sunshine hours, and humidity — visit our Guerneville climate page.
