All Variables

The Hottest Day describes the warmest daytime temperature in the selected time period. In general, the hottest day of the year occurs during the summer months.

High temperatures are important. They determine if plants and animals can thrive, they limit or enable outdoor activities, define how we design our buildings and vehicles, and shape our transportation and energy use. However, when temperatures are very hot, people – especially the elderly – are much more likely to suffer from heat exhaustion and heat stroke. Many outdoor activities become dangerous or impossible in very high temperatures.

Technical Description:

The highest maximum temperature (T_max) in the selected time period. Use the Variable menu option to view annual, monthly or seasonal values for this index.

Mean temperature describes the average temperature for the 24-hour day.

The average temperature is an environmental indicator with many applications in agriculture, engineering, health, energy management, recreation, and more.

Technical description:

The average of the daily maximum temperature (T_max) and the daily minimum temperature (T_min). Use the Variable menu option to view annual, monthly or seasonal values for this variable.

Minimum temperature describes the coldest temperature of the 24-hour day. Typically, but not always, the minimum temperature occurs at night and so this variable is commonly referred to as the nighttime low.

The average lowest temperature is an environmental indicator with many applications in agriculture, engineering, health, energy management, recreation, and more.

Technical description:

The daily minimum temperature (T_min). Use the Variable menu option to view annual, monthly or seasonal values for this variable.

Maximum temperature describes the warmest temperature of the 24-hour day. Typically, but not always, the maximum temperatures occur during the day and so this variable is commonly referred to as the daytime high.

The average highest temperature is an environmental indicator with many applications in agriculture, engineering, health, energy management, recreation, and more.

Technical description:

The daily maximum temperature (T_max). Use the Variable menu option to view annual, monthly or seasonal values for this variable.

Days with Max Humidex > 30 describes the number of days where the Humidex is greater than 30. This index gives an indication of the number of hot and humid days in the selected time period.

The Humidex was developed by the Meteorological Service of Canada to describe how hot and humid the weather feels to the average person. In Canada, it is recommended that outdoor activities be moderated when the Humidex exceeds 30, and that all unnecessary activities cease when it passes 40 (Environment and Climate Change Canada, 2019).

Technical description:

The number of days with a maximum Humidex (HX) over 30.

Use the Variable menu option to view annual, monthly or seasonal values for this index.

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Days with Max Humidex > 35 describes the number of days where the Humidex is greater than 35. This index gives an indication of the number of hot and humid days in the selected time period.

The Humidex was developed by the Meteorological Service of Canada to describe how hot and humid the weather feels to the average person. In Canada, it is recommended that outdoor activities be moderated when the Humidex exceeds 30, and that all unnecessary activities cease when it passes 40 (Environment and Climate Change Canada, 2019).

Technical description:

The number of days with a maximum Humidex (HX) over 35.

Use the Variable menu option to view annual, monthly or seasonal values for this index.

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Days with Max Humidex > 40 describes the number of days where the Humidex is greater than 40. This index gives an indication of the number of hot and humid days in the selected time period.

The Humidex was developed by the Meteorological Service of Canada to describe how hot and humid the weather feels to the average person. In Canada, it is recommended that outdoor activities be moderated when the Humidex exceeds 30, and that all unnecessary activities cease when it passes 40 (Environment and Climate Change Canada, 2019) Warm Season Weather Hazards.

Technical description:

The number of days with a maximum Humidex (HX) over 40.

Use the Variable menu option to view annual, monthly or seasonal values for this index.

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Days with Tmin <-15°C describes the number of days where the lowest temperature of the day is colder than -15°C. This index gives an indication of the number of very cold days in the selected time period.

Cold weather is an important aspect of life in Canada, and many places in Canada are well adapted to very cold winters. Cold temperatures affect our health and safety, determine what plants and animals can live in the area, limit or enable outdoor activities, define how we design our buildings and vehicles, and shape our transportation and energy use.

Technical description:

The number of days with a minimum temperature (T_min) less than -15°C.

Use the Variable menu option to view annual, monthly or seasonal values for this index.

Days with Tmin <-25°C describes the number of days where the lowest temperature of the day is colder than -25°C. This index gives an indication of the number of extreme cold days in the selected time period.

Cold weather is an important aspect of life in Canada, and many places in Canada are well adapted to very cold winters. Cold temperatures affect our health and safety, determine what plants and animals can live in the area, limit or enable outdoor activities, define how we design our buildings and vehicles, and shape our transportation and energy use.

Technical description:

The number of days with a minimum temperature (T_min) less than -25°C. Use the Variable menu option to view annual, monthly or seasonal values for this index.

Days with Tmax > 25°C describes the number of days where the daytime high temperature is warmer than 25°C. This index gives an indication of number of summer days in the selected time period.

High temperatures are important. They determine if plants and animals can thrive, they limit or enable outdoor activities, define how we design our buildings and vehicles, and shape our transportation and energy use. However, when temperatures are very hot, people – especially the elderly – are much more likely to suffer from heat exhaustion and heat stroke. Many outdoor activities become dangerous or impossible in very high temperatures.

Technical description:

The number of days with a maximum temperature (T_max) greater than 25°C. Use the Variable menu option to view annual, monthly or seasonal values for this index.

Days with Tmax > 27°C describes the number of days where the daytime high temperature is warmer than 27°C.

High temperatures are important. They determine if plants and animals can thrive, they limit or enable outdoor activities, define how we design our buildings and vehicles, and shape our transportation and energy use. However, when temperatures are very hot, people – especially the elderly – are much more likely to suffer from heat exhaustion and heat stroke. Many outdoor activities become dangerous or impossible in very high temperatures.

Technical description:

The number of days with a maximum temperature (T_max) greater than 27°C. Use the Variable menu option to view annual, monthly or seasonal values for this index.

Days with Tmax > 29°C describes the number of days where the daytime high temperature is warmer than 29°C.

High temperatures are important. They determine if plants and animals can thrive, they limit or enable outdoor activities, define how we design our buildings and vehicles, and shape our transportation and energy use. However, when temperatures are very hot, people – especially the elderly – are much more likely to suffer from heat exhaustion and heat stroke. Many outdoor activities become dangerous or impossible in very high temperatures.

Technical description:

The number of days with a maximum temperature (T_max) greater than 29°C. Use the Variable menu option to view annual, monthly or seasonal values for this index.

Days with Tmax > 30°C describes the number of days where the daytime high temperature is warmer than 30°C. This index gives an indication of number of hot days in the selected time period.

High temperatures are important. They determine if plants and animals can thrive, they limit or enable outdoor activities, define how we design our buildings and vehicles, and shape our transportation and energy use. However, when temperatures are very hot, people – especially the elderly – are much more likely to suffer from heat exhaustion and heat stroke. Many outdoor activities become dangerous or impossible in very high temperatures.

Technical description:

The number of days with a maximum temperature (T_max) greater than 30°C. Use the Variable menu option to view annual, monthly or seasonal values for this index.

Days with Tmax > 32°C describes the number of days where the daytime high temperature is warmer than 32°C. This index gives an indication of number of very hot days in the selected time period.

High temperatures are important. They determine if plants and animals can thrive, they limit or enable outdoor activities, define how we design our buildings and vehicles, and shape our transportation and energy use. However, when temperatures are very hot, people – especially the elderly – are much more likely to suffer from heat exhaustion and heat stroke. Many outdoor activities become dangerous or impossible in very high temperatures.

Technical description:

The number of days with a maximum temperature (T_max) greater than 32°C. Use the Variable menu option to view annual, monthly or seasonal values for this index.

The Coldest Day describes the lowest nighttime temperature in the selected time period. In general, the coldest day of the year occurs during the winter months.

Cold weather is an important aspect of life in Canada, and many places in Canada are well adapted to very cold winters. Cold temperatures affect our health and safety, determine what plants and animals can live in the area, limit or enable outdoor activities, define how we design our buildings and vehicles, and shape our transportation and energy use.

Technical Description:

The lowest minimum temperature (T_min) in the selected time period. Use the Variable menu option to view monthly, seasonal and annual values for this index.

The Last Spring Frost marks the approximate beginning of the growing season for frost-sensitive crops and plants. When the lowest temperature of the day remains above 0°C for one consecutive day (before July 15^th) the date of the last spring frost is established.

Technical description:

The spring date after which there are no daily minimum temperatures during the growing season less than 0°C (T_min > 0°C). Because this variable is largely used to assess the beginning of the growing season in southern Canada, the latest possible date for a spring frost was set as July 15. Use the Variable menu option to view values for this index on the map.

The First Fall Frost marks the approximate end of the growing season for frost-sensitive crops and plants. When the lowest temperature of the day is colder than 0°C for one consecutive day (after July 15^th) the date of the first fall frost is established.

Technical description:

The first date in the fall (or late summer) on which the daily minimum temperature is less than 0°C (T_min < 0°C). Because this variable is largely used to assess the end of the growing season in southern Canada, the earliest possible date for a fall frost was set as July 15. Use the Variable menu option to view values for this index on the map.

The Frost Free Season is the approximate length of the growing season during which there are no freezing temperatures to kill or damage frost-sensitive plants. This index describes the number of days between the Last Spring Frost and the First Fall Frost.

Technical description:

The number of days between the date of the last spring frost and the date of the first fall frost, equivalent to the number of consecutive days during the ‘summer’ without any daily minimum temperatures below 0°C. Use the Variable menu option to view values for this index on the map.