Agriculture Module Context

Canadian agriculture has always contended with climate variability and a changing climate may bring new or heightened challenges, including moisture extremes and the introduction of new pests in addition to opportunities to introduce crops with higher heat requirements under a longer, warmer growing season. The agriculture sector module on provides an overview of several key climate change impacts for agriculture through case studies and access to climate datasets. This page provides background information on how climate change may affect Canadian agriculture and highlights key information that can be found in the module.

Climate Change and Agriculture

Canada’s agriculture and agri-food sector accounted for roughly 12.5% of total employment in 20161. A changing climate has direct implications for the agricultural sector, including extreme weather events, changing crop suitability, pest distribution, and water availability2,3, making it a priority for inclusion on Canada’s agricultural sector is used to working with climate variability and has already implemented adaptation actions to reduce its risk to this variability. Access to climate model data can provide stakeholders in the sector with a better idea of how the climate is expected to change in their region and case studies provide examples of additional impacts and the use of climate data to better understand changing risks. The information available on is intended to inform adaptation by informing decision making, program priorities and investment decisions taken to manage additional risks of climate change.

The agriculture sector module was developed with input from a variety of stakeholders in Canada’s agricultural sector through a survey as well as engagements with experts and stakeholders. The module is currently targeted towards anyone in the agricultural sector and can inform long-term adaptation and risk management decisions.

While module content focuses primarily on Canadian impacts, the global nature of climate change means that impacts around the world will likely have indirect effects on Canadian agriculture through changes in global supply chains and trade3,4. provides data from an ensemble of 24 global climate models which have been downscaled and bias adjusted using the ANUSPLIN-derived gridded historical dataset. Consequently, only maximum and minimum temperature and precipitation, and several climate indices based on these three variables, are currently available. Survey results indicated that wind, soil moisture and snow cover information is also required by stakeholders; unfortunately, it is not currently possible to provide these variables on The Learning Zone section of provides further information on historical datasets, using climate data for decision making, and climate projection ranges.

Many agricultural decisions, particularly at the farm level, are made on shorter time scales than the 30-year horizons. Seasonal weather forecasts can be accessed through the Canadian Climate Data and Scenarios website. The Canadian Drought Monitor provides a variety of information on current and historical drought conditions across Canada. AgWeather Quebec  provides weather information (real-time data, forecasts, agroclimatic indices, models) that is tailored to the agricultural sector for Québec.

Agriculture Sector Module Content

The agriculture sector module has been designed to provide information about the priority issues for the sector associated with climate change and the role of climate data. The initial stakeholder survey helped identify climate variables and indices of interest for the sector, data format, and key impacts of concern which include extreme weather, crop suitability, and the distribution of pests, weeds, and diseases. Climate model data can also be viewed by census subdivisions on which has been highlighted for the agriculture sector module.

Moisture Extremes

Changes in the frequency and severity of extreme weather events, including windstorms, floods, and drought, are likely to be the most challenging impacts for the agricultural sector3,5. The stakeholder survey indicated that extreme or unpredictable weather was the key current impact of climate variability on stakeholders’ work.

Heavy rainfalls can make it difficult for farmers to access fields, pose drainage challenges, and reduce yields. A warmer climate and associated increased moisture holding capacity of the atmosphere is expected to result in increased extreme precipitation6. provides data for several relevant indices for assessing changes in excess moisture, including maximum 1-day precipitation and wet days above several thresholds (1 mm, 10 mm, and 20 mm). Wet days above custom thresholds can also be determined using the Analyze page.

Drought is another significant hazard for agriculture which can be extremely challenging to adapt to, producing crop failures and water scarcity affecting livestock and other uses. Therefore, the agricultural module development included the addition of the Standardized Precipitation Evapotranspiration Index (SPEI) at the 3-month and 12-month time periods.

RCP 2.6

RCP 8.5


The SPEI provides an indication of the moisture balance (precipitation minus potential evapotranspiration), by combining projected changes in temperature and precipitation to give an indication of future drought risk. The agriculture sector module also includes a Drought and Agriculture case study focused on drought on the Prairies.

Length of the Growing Season

A variety of climatic and non-climatic factors determine what shape agriculture takes in a given region7. An important climatic consideration is the length of the available growing season. As part of module development, indices for the last spring and first fall frost dates and total length of the frost-free season were added. The last spring frost index on indicates the first date with minimum temperatures greater than 0°C (before July 15) and the first fall frost indicates the first date where minimum temperatures fall below 0°C (after July 15). The frost-free season is computed as the number of days between these two dates and provides an approximate indication of the length of the available growing season. The total length of the growing season is projected to increase, consistent with anticipated warming.

The length of the growing season is one of several other factors associated with climate change that affect average crop and forage suitability, including higher temperatures, increased CO2 concentrations, available heat units, water availability, extreme weather events, and, in coastal regions, sea level rise2,3. The confluence of these factors on Canadian agriculture is challenging to predict, although the Risk Management in the Grape and Wine Industry case study illustrates how multiple climatic and non-climatic considerations can be considered to manage and better understand future risk.

Extreme Heat & Heat Units

Increasing mean and extreme temperatures can have a variety of effects on grain and livestock agriculture. Extreme heat above critical thresholds can be detrimental for crop development, particularly during key flowering and seed development stages8. High temperatures or heat waves during summer can also have negative effects for livestock, including heat stress, reduced milk production, and reduced summer weight gain2. provides projections for various indices of extreme heat, including maximum annual temperature and the number of days above a variety of maximum temperature threshold values. The projected frequency of several heat wave indices, using custom thresholds can be assessed using the Analyze page.

Warmer conditions throughout Canada also affect the available heat units for crop development. Growing Degree Days (GDD) describe the amount of heat available for crop growth by accumulating degree days when daily mean temperatures exceed a given threshold. Different crops have different heat requirements (further discussed in the Risk Management in the Grape and Wine Industry case study) and so projections of GDD using threshold temperatures of 5°C and 10°C are available on The Analyze page permits the calculation of GDDs using different threshold temperatures.

Available heat units also affect the distribution of pests, weeds, and diseases, with warmer conditions possibly permitting increased overwintering, potential for the development of multiple generations in a year, and range expansion. This is further discussed in the Crop Pests and Climate Change case study. The threshold for survival varies by crop and pest, so to provide additional flexibility in analyzing future projections, the analysis tool on includes a custom Degree Days Above a Threshold tool on the Analyze page.

Next Steps

The agriculture sector module has been developed based on the feedback received from stakeholders in this sector. is continuing to seek feedback on the agriculture sector module and add new content and climate indices. Please complete the feedback form on if you have any feedback on the current content or ideas for additional case studies, climate indices, or relevant datasets that you would like to see added to the agriculture sector module.


  1. Agriculture and Agri-Food Canada. (2020): An Overview of the Canadian Agriculture and Agri-Food System 2017. Online:
  2. Warren, F.J. (2004): Agriculture. In: Lemmen, D.S. and Warren, F.J. (Editors). Climate Change Impacts and Adaptation: A Canadian Perspective. Natural Resources Canada: Ottawa, Ontario. 51-70 p. ISBN: 0-662-33123-0
  3. Kulshreshtha, S. (2019): Resiliency of Prairie Agriculture to Climate Change. In: Climate Change and Agriculture. DOI: 10.5772/intechopen.87098
  4. Dellink, R., Hyunjeong, H., Lanzi, E., & Chateau, J. (2017): International trade consequences of climate change. OECD Trade and Environment Working Papers, 2017/01, OECD Publishing, Paris. DOI: 10.1787/9f446180-en
  5. Sauchyn, D., Davidson, D., & Johnston, M. (2020): Prairie Provinces; Chapter 4. In: Warren, F.J., Lulham, N. and Lemmen, D.S. (Editors). Canada in a Changing Climate: Regional Perspectives Report. Government of Canada, Ottawa, Ontario. Online:
  6. Cannon, A.J., Jeong, D.I., Zhang, X., & Zwiers, F.W. (2020): Climate-resilient buildings and core public infrastructure 2020: an assessment of the impact of climate change on climatic design data in Canada. Prepared for: Environment and Climate Change Canada.
  7. Bradshaw, B., Dolan, H., & Smit, B. (2004): Farm-level adaptation to climatic variability and change: Crop diversification in the Canadian Prairies. Climatic Change, 67: 119-141. DOI: 10.1007/s10584-004-0710-z
  8. Qian, B., Jing, Q., Bélanger, G., Shang, J., Huffman, T., Liu, J., & Hoogenboom, G. (2018): Simulated canola yield responses to climate change and adaptation in Canada. Biometry, Modeling & Statistics, 110, 133–146.