Area Weather Summary
In order to apply manure at appropriate times throughout the year, it is vital to have an understanding of the climate in your area, as well as seasonal weather patterns and current conditions. The following climatic summary gives you some guidelines and tips on understanding the weather.
Precipitation Summary to Date
The following table shows the historical and current precipitation amounts for Lynden, WA. While you may not live in Lynden, you can get a sense of the total amount of precipitation we have had this year compared to previous years. Use this information to assess your current storage and understand the conditions that contribute to storage capacity and manure application timing.
Table 1. Annual precipitation for Lynden, WA by month with total annual rainfall and total storage period (Oct-Mar) values listed
- Storage Period Total = the total amount of precipitation received from October 1 to March 31. You have to look at two years for this information. For example the storage period for 2012 is calculated from Oct 2011 to Mar 2012.
How to Interpret Weather
The average annual precipitation for the Lynden/Everson area is approximately 48 inches (your specific rainfall amount will vary). The graphs below represent typical annual trends in precipitation and temperature, respectively. The understanding of these graphs will help you make more educated and better decisions about when to apply manure to avoid unwanted resource pollution.
In order to avoid negative soil and water quality impacts (i.e., runoff, soil saturation, compaction, etc.) and properly manage crop irrigation needs, one of the most important climatic characteristics that should be observed on a daily basis is precipitation. The precipitation graph here shows the annual rainfall pattern, which gives an idea of timing and quantity of typical rain events during the year for your area. This data is important when timing grazing events, manure application times, and irrigation patterns.
The 5-day forecast should always be reviewed prior to any manure application to make sure there are no significant rain events (>0.50 inches) forecasted within the three days (72 hours) following application. This will significantly decrease the possibility of runoff events from your fields, thus reducing the loss of nutrients, pathogens, and soil sediment. It will also reduce the incidence of soil compaction, destruction of grass, and rutting in your fields from equipment. For instance, according to the precipitation graph shown, manure application should be conducted during the periods of low rainfall (highlighted in green boxes), as long as your field conditions allow. Manure should not be applied at a time when rainfall is at its highest frequency (major rain events highlighted in red circles), runoff events are likely, or plant need and uptake is very low (Sept-Jan). Lastly, observation of past and predicted rain events can help you better utilize irrigation water and timing throughout the year.
Temperature is also an important climatic variable to watch. Temperature is an indicator of estimated plant growth and animal feed intake, as well as nutrient losses from applied manure via ammonia volatilization (occurs when temperatures are high) and irrigation needs. The precipitation graph shown outlines the typical temperature pattern for a given year. Tracking temperature trends will help you better target manure applications to minimize ammonia losses from fields (apply during cooler periods), and more accurately predict when you will need to apply irrigation water throughout the year.
Other Climatic Data
Additional climatic data that is helpful to observe includes: wind direction, which is important to consider during manure application events to avoid blowing odorants to surrounding neighbors and manure droplets into surrounding ditches and water bodies; and wind speed, which if too high, will waste manure nutrients with wind dispersion and volatilization from the soil surface.
Refer to Weather for links for historical, predicted, and accurate and up-to-date climatic and weather data for your area.