Agriculture and Agri-Food Canada

Last Spring Frost (0 °C) is defined as the average day, during the first half of the year, of the last occurrence of a minimum temperature at or below 0 °C. These values are calculated across Canada in 10x10 km cells.

Crop/Corn Heat Units (CHU) is a temperature-based index often used by farmers and agricultural researchers to estimate whether the climate is warm enough to grow corn. Daily crop heat units are calculated from minimum and maximum temperatures with separate calculations for day and night. The...

Growing Degree Days (GDDs) are used to estimate the growth and development of plants and insects during the growing season. Insect and plant development are very dependent on temperature and the daily accumulation of heat. The amount of heat required to move a plant or pest to the next...

First Fall Frost (-2 °C) is defined as the average day of the second half of the year with the first occurrence of the minimum temperature of a climate day which is at or below -2 °C. These values are calculated across Canada in 10x10 km cells.

Monthly 30-year Average Maximum Temperature represents the average monthly maximum temperature calculated for a given location averaged across a 30 year period (1961-1991, 1971-2000, 1981-2010, 1991-2020). These values are calculated across Canada in 10x10 km cells.

Frost Day Count (0 °C) is defined as the number of days in a calendar month where the minimum daily temperature for the climate day was at or below 0 °C. These values are calculated across Canada in 10x10 km cells.

Growing Degree Days (GDDs) are used to estimate the growth and development of plants and insects during the growing season. Insect and plant development are very dependent on temperature and the daily accumulation of heat. The amount of heat required to move a plant or pest to the next...

Frost Day Count (-2 °C) is defined as the count of the number of days in a calendar month where the minimum daily temperature for the climate day was at or below -2 °C. These values are calculated across Canada in 10x10 km cells.