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30-year Average Minimum Temperature is computed by summing the “average monthly minimum temperature values” at a location for a given month (January-December) over the normal period, and dividing the result by 30 (the number of instances of that month over the 30 year period).

These values are calculated across Canada in 10x10 km cells.

Climate Data Products at Environment Canada comprise of four different datasets: Almanac Averages and Extremes, Monthly Climate Summaries, Canadian Climate Normals, and Canadian Historical Weather Radar. Almanac Averages and Extremes provides average and extreme temperature and precipitation values for a particular station over its entire period of record. Monthly Climate Summaries contains values of various climatic parameters, including monthly averages and extremes of temperature, precipitation amounts, degree days, sunshine hours, days without precipitation, etc. Canadian Climate Normals are used to summarize or describe the average climatic conditions of a particular location.

Percent of normal soil moisture is the modelled amount of plant available water (mm) in the root zone of the soil, divided by the average amount that has historically been available on that day. This value is intended to provide users with a representation of conditions above or below normal as a percentage.

Values are computed using the Versatile Soil Moisture Budget (VSMB)

Difference from normal soil moisture is the modelled amount of plant available water (mm) in the root zone of the soil, minus the average amount that has historically been available on that day. This value is intended to provide users with a representation of conditions above or below normal and by the amount of water (mm).

Values are computed using the Versatile Soil Moisture Budget (VSMB)

Growing degree days (GDDs) are used to estimate the growth and development of plants and insects during the growing season. Growing Degree Day are computed by subtracting a base value temperature from the mean daily temperature and are assigned a value of zero if negative. Base temperatures are a point below which development does not occur for the organism in question. Growing Degree Day products are created for base 0, 5, 10 and 15 degrees Celsius.

Maximum Temperature represents the highest recorded temperature value (°C) at each location for a given time period. Time periods include the previous 24 hours and the previous 7 days from the available date where a climate day starts at 0600UTC.

Minimum Temperature represents the lowest recorded temperature value (°C) at each location for a given time period. Time periods include the previous 24 hours and the previous 7 days from the available date where a climate day starts at 0600UTC.

Seasonal temperature climatology of the Northeast Pacific Ocean was computed from historical observations including all available conductivity-temperature-depth (CTD), bottle, expendable bathy-thermograph (XBT), and Argo data in NOAA (http://www.argo.ucsd.edu/), Marine Environmental Data Service (MEDS), and Institute of Ocean Sciences archives over 1980 to 2010 period. Calculations, including smooth and interpolation, were carried out in sixty-five subregions and up to fifty-two vertical levels from surface to 5000m. Seasonal averages were computed as the median of yearly seasonal values. Spring months were defined as April to June, summer months were defined as July to September, fall months were defined as October to December, and winter months were defined as January to March.

Departure from Average Precipitation represents the accumulated precipitation value for a location, subtracted by the long term average value. The long term average value is defined as the average amount over the 1981 – 2010 period. A negative value indicates that the location has received less than the normal amount of precipitation (mm) for that timeframe. A positive value indicates that the location has received more than the normal amount of precipitation (mm).

Crop Heat Units (CHU) are calculated on a daily basis, using the maximum and minimum temperatures in order to account for a crop’s negative response to higher temperatures.

The formula used to calculate the CHU value for a day is:

(1.8 × (Minimum Temperature − 4.4) + 3.33 × (Maximum Temperature − 10) − 0.084 × (Maximum Temperature − 10)²) ÷ 2.0

CHU values are only accumulated during the Growing Season, April 1 through October 31.