Weather plays a role in determining the types of plants that live here, including temperature and water supplies. Snow is rare in Seattle because the weather is influenced by the ocean and the Puget Sound. These large bodies of water moderate air temperature. The high specific heat index of water regulates the rate at which air changes temperature, and air over water remains cooler than that over land.

While there are several scenarios that create a snowfall in Seattle, the most common one requires cold, arctic air to move south out of Canada. If that air hovers just on the other side of the Cascades and then lower pressure air moves in offshore, it draws that arctic air southwest through the Fraser River Valley and then to rest of Western Washington. Any moisture in the air can then convert to snow.

But for the most part, our maritime climate keeps our temperatures mild, our winters wet, and our summers dry. You are much more likely to see snowberries in the winter than to see snow. Right now you'll find the snowberry bush with white seeds still attached to bare branches, a winter food source for birds.

Snowberries are found throughout North America, and are fairly common in the Pacific Northwest. But snowberry is endangered or threatened in many eastern states. Our Northwest variant is Symphoricarpos albus var. laevigatus, the Pacific Slope Snowberry. This plant has many uses, such as helping stabilize soils on banks and slopes, because of its extensive root systems.

Meriweather Lewis collected the Pacific Slope Snowberry and took specimens of it home to Thomas Jefferson. Jefferson shared cuttings and sent them to friends, most notably in 1813 to Madame La Comtesse de Tesse in France. European plant breeders took to it immediately, and S. albus still has a devoted following there.

On these long nights and dark days of rain, the white drops of snowberries clinging to their limbs offer a reminder of the blossoms of spring and the light that will soon return.