The dataset contains the blended (gauge and satellite estimates) monthly mean precipitation rates (unit: mm/day) for Canada for the period from January 1979 to December 2007, at a half degree spatial resolution. Please refer to the paper below for the details of the blending algorithm and input gauge and satellite data. Reference: Lin, A. and X. L. Wang, 2011: An algorithm for Blending Multiple Satellite Precipitation Estimates with in-situ Precipitation Measurements in Canada. JGR-Atmospheres, 116, D21111, doi:10.1029/2011JD016359.

Seasonal and annual trends of relative total precipitation change (%) for 1948-2012 based on Canadian gridded data (CANGRD) are available, at a 50km resolution across Canada. The relative trends reflect the percent change in total precipitation over a period from the baseline value (defined as the average over 1961-1990 as the reference period). CANGRD data are interpolated from adjusted and homogenized climate station data (i.e., AHCCD datasets). Adjusted precipitation data incorporate adjustments to the original station data to account for discontinuities from non-climatic factors, such as instrument changes or station relocation.

Seasonal and annual trends of mean surface air temperature change (degrees Celsius) for 1948-2016 based on Canadian gridded data (CANGRD) are available at a 50km resolution across Canada. Temperature trends represent the departure from a mean reference period (1961-1990). CANGRD data are interpolated from adjusted and homogenized climate station data (i.e., AHCCD datasets). Homogenized climate data incorporate adjustments to the original station data to account for discontinuities from non-climatic factors, such as instrument changes or station relocation.

Gridded monthly, seasonal and annual anomalies derived from daily total precipitation is available at a 50km resolution across Canada. The Canadian gridded data (CANGRD) are interpolated from adjusted precipitation (i.e., AHCCD datasets). Adjusted precipitation data incorporate adjustments to the original station data to account for discontinuities from non-climatic factors, such as instrument changes or station relocation. The anomalies are the percentage difference between the value for a given year or season and a baseline value (defined as the average over 1961-1990 as the reference period). The yearly and seasonal relative precipitation anomalies were computed for the years 1948 to 2014. The data will be updated as time permits.

Gridded monthly, seasonal and annual mean temperature anomalies derived from daily minimum, maximum and mean surface air temperatures (degrees Celsius) is available at a 50km resolution across Canada. The Canadian gridded data (CANGRD) are interpolated from homogenized temperature (i.e., AHCCD datasets). Homogenized temperatures incorporate adjustments to the original station data to account for discontinuities from non-climatic factors, such as instrument changes or station relocation. The anomalies are the difference between the temperature for a given year or season and a baseline value (defined as the average over 1961-1990 as the reference period). The yearly and seasonal temperature anomalies were computed for the years 1948 to 2017. The data will continue to be updated every year.

High-resolution statistically downscaled climate indices relevant to climate change impacts in Canada are available at a 10 km spatial resolution and an annual temporal resolution for 1951-2100. The climate indices are based on model projections from 24 global climate models (GCMs) that participated in the Coupled Model Intercomparison Project Phase 5 (CMIP5). To address the needs of different user groups in Canada, agroclimate indices and other indices that were proposed by the Canadian adaptation community through a series of consultations are provided. This range of climate indices are of relevance to adaptation planning for different sectors in Canada, such as human and ecological health, agriculture and energy. Available for download are indices that represent the counts of the number of days when temperature or precipitation exceeds (or is below) a threshold value; the lengths of episodes when a particular weather/climate condition occurs; and indices that accumulate temperature departures above or below a fixed threshold. Multi-model datasets of the statistically downscaled climate indices for historical simulations and three emission scenarios, RCP2.6, RCP4.5 and RCP8.5, are available. Both multi-model ensembles and individual model output are available for download. The fifth, 25th, 50th (median), 75th and 95th percentiles of the annual ensembles are available for each climate index, from 1951-2100. Note: Projections among climate models can vary because of differences in their underlying representation of earth system processes. Thus, the use of a multi-model ensemble approach has been demonstrated in recent scientific literature to likely provide better projected climate change information. Further, projected future changes by statistically downscaled products are not necessarily more creditable than those by the underlying climate model outputs. In many cases, especially for absolute threshold-based indices, projections based on downscaled data have smaller spread because of the removal of model biases. However, this is not the case for all indices. Downscaling from GCM resolution to the fine resolution needed for impacts assessment increases the level of spatial detail and temporal variability to better match observations. Since these adjustments are GCM dependent, the resulting indices could have wider spread when computed from downscaled data as compared to those directly computed from GCM output. In the latter case, it is not the downscaling procedure that makes future projection more uncertain; rather, it is indicative of higher variability associated with finer spatial scale.

Humidex (Masterton and Richardson 1979) is an index 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 (Mekis et al., 2015). With the increase in temperature projected by climate models over the coming decades over Canada, increases are also expected in the number of days with high-value Humidex across the country, which will have important consequences for human health. This dataset consists of a multi-model ensemble of statistically downscaled climate model projections for three humidex threshold indices (annual number of days when humidex exceeds 30, 35 and 40, noted HXmax30, HXmax35 and HXmax40 respectively) on a 0.1-degree latitude-longitude grid over Canada. The three indices (HXmax30, HXmax35 and HXmax40) are available for download at annual time step and 30-year averages from 1950 to 2100, for each of the 19 individual models and for the 10th, 50th, and 90th ensemble percentiles. The multi-model ensemble is using output from 19 Coupled Model Intercomparison Project Phase 6 (CMIP6) global climate models (GCM) that are available at the Earth System Grid Federation (ESGF) Data Nodes, for three emission scenarios called “Shared Socioeconomic Pathways” (SSPs) (Riahi et al. 2017): SSP126, SSP245 and SSP585. The GCM outputs were statistically downscaled and bias corrected using the N-dimensional probability density function transform multivariate quantile mapping method (Cannon, 2018) against ERA5-Land data (Muñoz, 2019), using a method described in Diaconescu et al. (2022). This method is based on the observation that the time when Humidex reaches its daily maximum coincide statistically with the time when temperature reaches its daily maximum and relative humidity reaches its daily minimum. In order to eliminate model biases and the errors in the adjustment method, the daily maximum temperature and daily minimum relative humidity from GCMs are statistically downscaled and bias corrected against the hourly temperature and relative humidity at the time of daily maximum humidex from ERA5-Land. The bias-corrected values are used to compute the daily maximum humidex and next the three threshold annual indices. These ensembles of indices are intended to enable users to better identify and reduce the susceptibility of vulnerable populations to illness and mortality due to increase in the frequency and intensity of extreme heat events due to climate change. References: Cannon, A. J. (2018). 'Multivariate quantile mapping bias correction: an N-dimensional probability density function transform for climate model simulations of multiple variables', Climate Dynamics, 50(1-2), 31-49. Available at https://doi.org/10.1007/s00382-017-3580-6 Diaconescu, E. P. et al. (2022) ' A short note on the use of daily climate data to calculate Humidex heat-stress indices', International Journal of Climatology, 1– 13. https://doi.org/10.1002/joc.7833 Masterton, J. M., and Richardson, F. (1979) 'Humidex: a method of quantifying human discomfort due to excessive heat and humidity', Environment Canada, Atmospheric Environment, 45. Mekis, É., et al. (2015) 'Observed trends in severe weather conditions based on humidex, wind chill, and heavy rainfall events in Canada for 1953–2012', Atmosphere-Ocean, 53, 383-397. Available at https://doi.org/10.1080/07055900.2015.1086970, (Accessed: 19 April 2022). Muñoz Sabater, J., 2019: ERA5-Land hourly data from 1981 to present. Copernicus Climate Change Service (C3S) Climate Data Store (CDS). (Accessed on < 25-Jun-2021 >), https://doi.org/10.24381/cds.e2161bac Riahi, K., van Vuuren, D. P., Kriegler, E., Edmonds, J., O’Neill, B. C., Fujimori, S., Bauer, N., Calvin, K., Dellink, R., Fricko, O., Lutz, W., Popp, A., Crespo Cuaresma, J., KC, S., Leimbach, M., Jiang, L., Kram, T., Rao, S., Emmerling, J., Ebi, K., Hasegawa, T., Havlik, P., Humpenöder, F., Aleluia Da Silva, L., Smith, S., Stehfest, E., Bosetti, V., Eom, J., Gernaat, D., Masui, T., Rogelj, J., Strefler, J., Drouet, L., Krey, V., Luderer, G., Harmsen, M., Takahashi, K., Baumstark, L., Doelman, J., Kainuma, M., Klimont, Z., Marangoni, G., Lotze-Campen, H., Obersteiner, M., Tabeau, A., & Tavoni, M. (2017). The Shared Socioeconomic Pathways and their energy, land use, and greenhouse gas emissions implications: An Overview. Global Environmental Change, 42, 153-168. https://doi.org/10.1016/j.gloenvcha.2016.05.009

The purpose of the Long-Range Forecast Transient Intercomparison Project (LRFTIP) is to provide an archive of hindcast climatologies, describing the systematic behavior of models evolving from observation-based initial states, that can inform investigations into the transient behavior of initialized subseasonal to decadal climate predictions, the development of model biases, and the relative merits of different initialization methods. The archive is based on publicly available hindcast datasets including the Subseasonal to Seasonal Prediction Project (S2S), the Climate-system Historical Forecast Project (CHFP) and the Coupled Model Intercomparison Project Phase 5 (CMIP5) and 6 (CMIP6). ECCC models include the GEPS-based contribution to S2S, the CanCM3, CanCM4, CanCM4i and GEM-NEMO seasonal prediction models, and the CanCM4 CMIP5 and CanESM5 CMIP6 decadal prediction models. Additional contributions are being added as they become available.

Multi-model ensembles for a suite of ocean variables based on projections from Coupled Model Intercomparison Project Phase 6 (CMIP6) global climate models (GCMs) are available for 1900-2100 on a common 1x1 degree global grid. All ocean variables currently available contain data for the top level (sea surface) of the ocean. Climate projections vary across GCMs due to differences in the representation and approximation of earth systems and processes, and natural variability and uncertainty regarding future climate drivers. Thus, there is no single best climate model. Rather, using results from an ensemble of models (e.g., taking the average) is best practice, as an ensemble takes model uncertainty into account and provides more reliable climate projections. Provided on CCDS are multi-model ensembles as well as individual model simulations. Multi-model output is available for historical simulations and six Shared Socioeconomic Pathways (SSPs) (SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP4-6.0, and SSP5-8.5), four future periods (near-term (2021-2040), mid-term (2041-2060 and 2061-2080), end of century (2081-2100), and up to eight percentiles (maximum, minimum, mean, 5th, 25th, 50th (median), 75th, and 95th) of the CMIP6 ensemble distribution. Datasets are available as both actual and anomaly values. Anomalies of projected changes are expressed with respect to a historical reference period of 1995-2014. The number of models in each ensemble differs according to model availability for each SSP and variable, see the model list resource for details on the models included in each ensemble. For more information on the CMIP6 multi-model ocean datasets, see the technical documentation resource.

The Canadian Centre for Climate Modelling and Analysis (CCCma) Earth System Grid Federation (ESGF) Dataset provides the Environment and Climate Change Canada (ECCC) node on an internationally-coordinated system of climate model data dissemination developed specifically for the World Climate Research Programme’s Coupled Model Intercomparison Project Phase 5 (CMIP5). More specifically, this dataset provides the department's climate model output for international use, particularly in support of the IPCC 5th Assessment. This dataset is of use in sophisticated climate model validation and climate change impact studies. The CCCma ESGF Dataset is compliant with specific international standards to ensure interoperability with other international climate modelling institutions. Data formats are complex; documentation is available at http://cmip-pcmdi.llnl.gov/cmip5/output_req.html. Note: This dataset comprises roughly 47TB of model output, in the CMIP specified file structure and NetCDF format. Data license agreement: This dataset is subject to the Open Government Licence - Canada. If the data are subject to any other agreements, these will be specifically noted with the data.