snow covered solar panels in staten island New YorkBy Theresa Ficazzola

So, how much does the weather impact solar panels and their production? Let’s examine a few scenarios. You just may be surprised by what you read.

Clouds, Rain and Fog

Contrary to popular opinion, solar panels still generate electricity on cloudy/rainy days or in foggy weather—they are just not producing as much energy as they do on bright, sunny days. On cloudy days, solar panels typically produce about 10% to 30% of their capacity. The exact amount depends on the type of solar panels, the density of the clouds or fog, and the duration of the clouds hovering over the home.

Germany, for example, which leads the world in solar energy installations and production, has many cloudy and rainy days. However, the sunshine they see over the course of a full year, makes up for the overcast days, so the weather doesn’t negatively impact the long-term advantages of going solar.

Rain and snow are actually beneficial for solar panels because they naturally wash off any dust, pollen and other irritants that may accumulate on the panels. Once a solar energy system is installed, there’s no maintenance. Nature takes care of producing your energy, and she also takes care of keeping your system clean!


While a little bit of snow is good for cleaning solar panels, the snow doesn’t really impede their production significantly since some sunlight can still pass through a thin coat of snow. And because the panels are typically installed at an angle to help with sun reflection, the tilt of the panels also acts as a slide for the snow to naturally fall off. Most average snow storms will leave a blanket of snow on roof panels; however, the sun that usually appears the day after a snow storm will typically melt the snow off the black solar panels which absorb the heat.

In fact, a big snow storm with a large blanket of snow around your home and street could actually increase your solar production because the sun reflecting off the snow acts as a mirror, boosting the intensity of the sunlight reaching your panels.

Hail, Wind and Lightning

Most solar panels are produced to withstand an average sized hail storm and winds of about 50 mph. There is always a chance that severe weather, such as large hail, lightning or hurricane force winds, could damage a residential solar energy system, but these situations are rare. Lightning strikes are a non-issue because they are required to be grounded at installation. In most cases, any potential damage caused by severe weather such as this would not be covered by a solar panel warranty; however, some homeowner’s insurance would. That’s why it’s critical to make sure your home solar panels are added to your homeowner’s insurance policy as soon as the system is turned on.

Extreme Heat

Many people believe that solar panels work best in the hot, sunny days of summer. However, this is not quite true. Solar panels are actually more productive when temperatures aren’t too hot because their production is more reliant on the amount of sunlight that hits the panels, not the actual temperature of the air surrounding them. A cooler, sunny day with an abundant amount of sunlight is much better for optimum production than a scorching hot summer day.

Some experiments conducted on the efficiency of solar panel production during hot weather have showed that on extremely hot days, when temperatures reached about 90 to 110 degrees Fahrenheit, solar energy production dropped steadily, but still not significantly to discount their benefits.

The “Best” Weather

Cooler, sunny days are the most efficient in terms of solar energy production. However, in the northeast, cold, sunny days are equated with late fall, winter and early spring, which also means shorter daylight hours. So while energy production is at an optimum peak, the number of hours that sunlight is hitting the panels is as its lowest point of the year.

As you can see, there is no “best” time to produce solar because weather patterns, sunlight production and the seasons of the year, all play their part in solar energy production. That’s why when you contract us to install solar on your home, we use a Solmetric SunEye meter to calculate annual, monthly and seasonal shading percentages at your home which allows us to design a system that meets your specific energy needs. The SunEye’s fisheye lens also scans the sky above your roof to identify shade-causing obstructions and to tell us how much additional energy would be produced if those obstructions were removed.

So, don’t waste another sunny day…contact SI Solar today and we will do a FREE site assessment at your home to determine exactly how much energy solar panels on your roof will produce. We’ll also show you how to get that system for $0 down when you call 844-747-6527!