St. Helena (CA) Sunshine Hours by Month

Sunshine plays a big role in understanding the climate of a city. This page shows the total number of hours of direct sunlight per month and the average hours per day in St. Helena, California, United States of America. These averages rely on historical data collected over 30 years, from 1990 to 2020.

Monthly hours of sunshine

Those who love seasonal contrasts will appreciate St. Helena. Expect long, bright days with 310 hours in May and darker periods with just 160 hours in December. The total annual amount of sun is 3042 hours.

Daily hours of sunshine

In St. Helena, summer days are longer and more sunny, with daily sunshine hours peaking at 10.3 hours in May. As the darker season arrives, the brightness of the sun becomes less. December sees a soft sun for only 5.3 hours per day.

Average percent of sunshine

On average the sun shines 79% of the time during the day in April, the highest percentage of any month. December has the lowest percentage at 55%.

St. Helena enjoys an average of 3042 hours of sunshine annually. Let’s compare this with some popular tourist destinations:

In Barcelona, Spain, there are 2530 hours of sunshine annually and is a city that can be visited year-round.

In contrast, Tromsø , Norway, receives only about 1270 hours of sunshine per year, known for the polar night with no sunlight for weeks during winter.

In Chicago, USA, the annual sunshine averages 2520 hours, contributing to its humid continental climate.

Melbourne, Australia, has 2380 hours of sunshine annually, with its famous “four seasons in a day” weather pattern.

December, St. Helena’s wettest month, receives 0.4 mm (0.02 in) of rainfall and has a maximum daytime temperature of 14°C (57°F). During the driest month August you can expect a temperature of 31°C (88°F).

For more detailed insights into the city’s temperatures, check out our Temperature page. To explore more about precipitation patterns, visit our St. Helena Precipitation page.