Geyserville (CA) Temperature by Month

The average annual maximum temperature in Geyserville, California, United States of America is 23°C (73°F), with daytime highs ranging from 14°C (57°F) in December to 31°C (88°F) in July. This page covers monthly averages, day-night differences, and how Geyserville compares to cities worldwide.

In Geyserville, temperatures differ significantly between summer and winter months. Nighttime lows reflect this range, dropping from 12°C (54°F) in July to 4°C (39°F) in December.

The chart below illustrates the average maximum day and minimum night temperatures in Geyserville 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. July, the city's warmest month, averages 306 hours of sunshine.

The chart below shows the average temperature throughout the year:

Geyserville's average annual maximum temperature is 23°C (73°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.

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.

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