Data Sources and Methods

Data sources and methods

Climate Model Data

The primary source of climate model data presented in our maps, charts and tables is the Pacific Climate Impacts Consortium (PCIC;

We downloaded PCIC’s statistically downscaled data (Bias Corrected Spatial Disaggregation; BCSD) derived from 12 CMIP5 global climate models (GCMs: ACCESS1.0, CanESM2, CCSM4, CNRM-CM5, CSIRO-Mk3-6.0, GFDL-ESM2G, HadGEM2-CC, HadGEM2-LR, INM-CM4, MPI-ESM-LR, MRI-CGCM3, MIROC5), for two emissions scenarios (RCP4.5 and RCP8.5). We call the RCP4.5 and RCP8.5 the “Low Carbon” and “High Carbon” scenarios, respectively.

For each model/scenario PCIC provided daily temperatures (maximum and minimum) and total precipitation at 10 km resolution for all of Canada, for the period 1950-2100 (note: since some of the models did not have data beyond 2095, we used this year as our cutoff for future time series).

Unless otherwise stated, the data we present are the averages (ensembles) of the 12-model suite.

For each model, the simulations for 1950-2005 were the same for both emissions scenarios (RCP4.5 and RCP8.5). The divergent emissions scenarios were used by the models starting in 2006. That is, starting in 2006 the model outputs for the two RCPs begin to differ.

Climate projections are provided for two future 30-year periods (2021-2050 and 2051-2080) and a baseline period (1976-2005).

Please visit our page “Important Data Notes and Limitations” to learn more these data and how they should be used.

Observed Data

For comparative purposes, observed data are included in all time-series graphs for the period 1950-2005. By providing both observed and modelled data over this period, it is possible for users to visually judge how well model projections match observations.

The source of the observed data used in the Atlas is Natural Resources Canada (NRCan; McKenney et al. 2011). These data contain daily maximum and minimum air temperature and daily precipitation totals at the same 10 km by 10 km gridded resolution as PCIC’s model data.

Please visit our page “Important Data Notes and Limitations” to learn more these data.


The raw model data arrays downloaded from PCIC are too large to process directly using GIS software. It was often desirable to analyze future climate changes using the ensemble of the 12 models, further magnifying the computational demands. As an intermediate step, we developed software using the IDL programming language to unpack the model data into daily files, compute summary statistics, and produce smaller output files that could be manipulated in ArcGIS, which was the software used to build the maps in the Atlas.

The maps in the Atlas do not contain all the raw 10 km by 10 km data.

Areal averages are provided across the National Topographic Service’s (NTS) 1:250,000 map grids and across Canada’s Provinces and Territories. The NTS grids were selected because they are available for all of Canada, have a spatially and climatically appropriate size of about 100 km by 100 km, and are helpfully named according to local landforms or major population centres, making them recognizable and useful to web users.

In addition to the spatially averaged data, nearest-neighbour analysis was used to compute point-value data for approximately 500 towns and cities across Canada. Again, this was done for the benefit of the web-user; having data made available for cities and towns makes these model data accessible and relevant for a wide sector the Canadian population. Indeed, one of the major objectives of the Atlas is to show Canadians how climate change is expected to change their local, personal climates.

Please visit our page “Important Data Notes and Limitations” to learn more this methodology.

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The information disseminated by the Prairie Climate Centre including but not restricted to maps, tables, statistics and interpretations is provided as a public service. It is provided without any warranty or representation, express or implied, as to its accuracy or completeness. Any reliance you place upon the information contained here is your sole responsibility and strictly at your own risk. In no event will the Prairie Climate Centre be liable for any loss or damage whatsoever, including without limitation, indirect or consequential loss or damage, arising from reliance upon the data or derived information.


Pacific Climate Impacts Consortium, University of Victoria, (Jan. 2014). Statistically Downscaled Climate Scenarios. Downloaded from on January 2015.

McKenney, D. W., Hutchinson, M.F., Papadopol, P., Lawrence, K., Pedlar, J., Campbell, K., Milewska, E., Hopkinson, R., Price, D., Owen, T. (2011). "Customized spatial climate models for North America." Bulletin of American Meteorological Society December: 1612-1622.