Seasonal weather is based upon many factors. As your water feature is located outdoors, your equipment, plants and animals will be affected by the seasons throughout the year. Choosing the right location, installing the correct gear, and adding the proper plants and animals will make your pond easy to maintain. However, you could be creating a maintenance nightmare if you do not consider seasonal changes.
Light: The farther south you live, the higher the sun will be as it crosses the sky from sunrise to sunset. In Hawaii (the southern-most state), the sun is nearly overhead most of the year. However, the sun’s zenith shifts seasonally the farther north you go and will be lower towards the horizon (angled) in winter. Conversely, the farther south you are, the more consistent the length of the day is throughout the year. In Hawaii, the sun comes up around 6am and sets about 6pm all year round. Here in Seattle, the length of the day stretches to nearly 16 hours long on summer solstice, but shrinks to a mere 8 hours during winter solstice! Direct sunlight can heat the water in your feature; provide light to the bottom of a deep pond, and change water chemistry too. The sun emits ultraviolet rays. UV rays act as a water sterilizer, killing bacteria and algae. It also can break down liners and plastic parts prematurely, and too much can be harmful to fish and plants. When the sun is overhead or at higher elevations where the air is thinner, UV can be more intense; even through clouds! Consider the annual light and plan accordingly.
Temperature: In general, the amount of sun and the farther south your location is, the annual ambient temps in general go up. However, elevation plays a big part in this. The higher your location is can affect the air temps even though the sun may be very bright and intense. Further, living near a large body of water can cool or warm your location as well. Here in Seattle, Puget Sound keeps both are winters and summers mild and give us long spring and autumn seasons. Wind is yet another affect on ambient temperatures. Wind is both cooling and drying. Water is a heat sync to the surrounding air at the surface. Warm air temps will be transferred to your cooler water temp (albeit at a slower rate). Conversely, when the water is warmer than the air, it will release its heat to the air (again, at a slower rate). A greater surface area will increase this exchange of heat.
Relative Humidity: Air can be dry or humid. The amount of water can hold depends on ambient air temps and air pressure. Pressure can change due to weather fronts and elevation. This can be fairly constant or change with the seasons as well. It also depends if there is any water to be had in your region. If you live in a dry desert, there will be little water to be gained from the land. Evaporation of your water feature will be greater in hot, dry situations exacerbated by sun and wind. The more water movement or water features you have can cause greater water loss too through diffusion and evaporation. Further, the greater the surface area ratio of your feature versus its depth exposes more evaporation across the water feature. Plan carefully.
Weather: On top of light, temperature, and humidity, regional weather patterns also play a role. The jet stream shifts during the year north to south and back again. Local land features like mountains play a role in weather too. In my case, I live just north of Seattle which is a temperate rainforest climatic zone. But I happened to live smack dab in the middle of something called the convergence zone; a local weather phenomena. A town about four miles from my home receives more sun per year than I do to the extent that the same flowers in my yard bloom 4-6 weeks later than there. It can be raining here and be sunny two miles north and south of my home. How much sun, precipitation, air temps, humidity can play a factor on your water feature too. For your own home annual weather statistics, search online for “annual weather trends” using your zip code.
Climatic and Hardiness Zones: There are so many variable to a location over the course of a year, that an average is taken of the seasons to come up with an overall. Perform a search for the Köppen-Geiger Climate Subdivisions map to locate your climatic zone. I live just north of Seattle in a temperate rainforest (Csb: warm summer Mediterranean) which is described as “coldest month averaging above 32°F, all months with average temp below 71.6°F, and at least four months averaging above 50°F. At least three times as much precipitation in the wettest month of winter as in the driest month of summer and driest month of summer receives less than 1.2”. According to hardiness planting zones, I live in zone 8b. Remember, these are averages. We get occasional lowland wet snow but our temps here rarely drop which would cause my pond to freeze over; and most homes do not even have AC. It could even vary in your own yard due to a line of trees that shade your water feature and create a windbreak! Note that many plants will note hardiness and both plants and animal care notations will likely mention temperatures as well. Be aware of annual temps or the amount of sun needed before choosing.
Seasonal Changes: If you live in a location that is mild year round, seasonally maintenance might be minor causing you to pick a date to do a major spring cleaning once a year (even if it’s not spring). However, if you live in an area that has drastic seasonal changes, the above factors may force exactly when you must perform maintenance; and may require components, plants or fish to be removed as not doing so could cause pond equipment failures or injure or kill the flora and fauna.
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