Frost free days are the number of days in the forecast period with a minimum temperature above the frost temperature; the temperature at which frost damage occurs. This temperature is -2°C for cool season crops (ffd_cool).
Week 1 and week 2 forecasted index is available daily from April 1 to October 31.
Week 3 and week 4 forecasted index is available weekly (Thursday) from April 1 to October 31.
Cool season crops require a relatively low temperature condition. Typical examples include wheat, barley, canola, oat, rye, pea, and potato. They normally grow in late spring and summer, and mature between the end of summer and early fall in the southern agricultural areas of Canada. The optimum temperature for such crops is 25°C.
Agriculture and Agri-Food Canada (AAFC) and Environment and Climate Change Canada (ECCC) have together developed a suite of extreme agrometeorological indices based on four main categories of weather factors: temperature, precipitation, heat, and wind. The extreme weather indices are intended as short-term prediction tools and generated using ECCC’s medium range forecasts to create a weekly index product on a daily and weekly basis.