Farming with Seasonal Urban Wind Patterns
Understanding wind flow and how it affects your landscape may be useful to you in your sustainable farming efforts. Perhaps you would like to screen against harsh winter winds or channel in a cool summer breeze?
Wind flow is created by the sun heating the air. Of course the direction of winds varies quite a bit. Wind patterns change seasonally due to the angles and changes of our sun.
The direction of wind is determined from where it originates. A southerly wind will blow from the south to the north and a northerly wind will blow from the north to the south. For the majority of the U.S., many summer breezes come from the south or southwest. During the winter, wind patterns usually come from the northwest or northerly direction. This can vary greatly depending on where you live.
Because wind patterns vary greatly across the country, the best way to find out the general direction of summer breezes and prevailing winter winds in your area is to contact your local national weather service contact office. To find out who your local contact is, start your search at National Weather Service.
A Wind Map compiles data from the National Weather Service and their national digital forecast database on an hourly basis into a living portrait of wind flow for the continental U.S. Here, you can zoom in and analyze the directional wind patterns for your area in real time.
Another popular site to visit is The Weather Channel, where their new interactive map allows you to view past, current, and future weather projections locally. You can also customize the map to review wind speeds in your region.
Of course there are special circumstances you can also keep in mind when it comes to wind direction and flow. For instance, if your urban residence is fronting near a large body of water or along the coastline, the wind pattern here would likely flow much differently than that of an inland property.
Within our inner cities, tall buildings that project above other structures could channel air downward along the windward face of the building; also known as wind tunnels, these added winds can certainly affect our comfort levels.
With an understanding of urban wind patterns, how can you effectively design your urban gardens with wind in mind? While canopies at the base of buildings and other structures may help shelter against strong downward gusts of air, adding landscape features, trees, and plantings can help channel or protect against horizontal wind flows. Here are some additional tips you can consider to effectively approach wind flow in the urban landscape:
In urban climates with hot summers, your goal may be to block the summer sun while channeling a summer southerly breeze. One way to do so is to place a semicircular row of deciduous trees and shrubs from southeast to southwest with a break in the middle (south).
The trees can help channel these southerly gusts of wind into your urban garden while providing you some additional shade against the direct sunlight. This can help cool down an area of your urban landscape at a microclimate level.
In urban climates with cold winters, the goal is to block against the strong, cold winter winds with a row of trees and shrubs while continuing to capture the winter sun and maximize solar exposure. A dense row of evergreens placed appropriately (usually north and northwest) can be a very effective screen against cold winter winds.
When you put in a garden in the spring, you may need to put up a temporary wind screen to help protect tender new transplants and seedlings from the drying effects of the cold and harsh late winter winds.
In temperate urban climates, which include the majority of U.S. cities, city planners have to employ both of these strategies to protect against winter winds while channeling summer breezes.