Fine-scale gridded monthly climatologies
Within the fine-scale gridded monthly climatologies portal, users can:
- Access the BC PRISM and Canada Mosaic datasets, with monthly historical data for minimum temperature, maximum temperature, and precipitation
- Use an interactive map to zoom, pan and select regions across Canada
- Select time averages (annual, monthly, or 30-year climatology)
- Create spatial subsets of data (current view, sub-region, point)
- Adjust geospatial projection, colour scale and range
- Download data in NetCDF format
Both datasets are based on observed station data and have been statistically downscaled to a fine spatial resolution (1 km × 1 km or finer). This downscaling incorporates additional information such as topography and other influencing factors to improve local accuracy. More details on each dataset are provided below.
About the BC PRISM dataset
The climate of British Columbia varies greatly across the province due to its complex topography, mix of coastal and continental influences, and large north-south extent. This makes it challenging to describe detailed climate patterns using weather station data alone. The PRISM method, described below, helps address this by representing climatologies of BC at a much finer scale.
The Parameter-elevation Regressions on Independent Slopes Model (PRISM), developed by the PRISM Climate Group at Oregon State University, leverages the known strong relationship between elevation and climate, along with a high-resolution digital elevation model and extensive station observations, to estimate monthly climatological values on a regular grid of horizontal scale less than 1km. It integrates data from thousands of temperature and precipitation stations in British Columbia and neighbouring regions, including Yukon, Alberta, Alaska, Washington, Idaho, and Montana.
The procedure involves weighting factors to account for station clustering, differences in record length, proximity to the ocean, and topographic aspect. PRISM also uses a two-layer atmosphere model, incorporating data from the North American Regional Reanalysis to better represent temperature inversions.
PRISM has been widely tested and verified across the United States and has been applied in numerous countries across the globe, including in western Canada for the 1961-1990 normal period. Since 2011, PCIC has worked in partnership with Oregon State University to apply PRISM to observational data in British Columbia.
Please cite the BC PRISM dataset as:
- Pacific Climate Impacts Consortium, University of Victoria, and PRISM Climate Group, Oregon State University, (2014, 2024). High Resolution Climatology. Downloaded from <Permalink> on <Date>.
The 1981-2010 and 1991-2020 maps benefit from substantial data contributions by Alberta Agriculture and Irrigation (AGI), which maintains and quality controls observations collected by the Province of Alberta and Environment and Climate Change Canada. Data from AGI were critical for accurately representing the climate near the BC-Alberta border.
We also gratefully acknowledge financial support and expert review from The Bonneville Power Administration and the National Oceanic and Atmospheric Administration Northwest River Forecast Center. Their contributions enabled the production of high-quality maps for both the 1981-2010 and 1991-2020 climate normals periods.
We thank the PRISM Climate Group for their ongoing guidance and technical support.
Finally, this work would not have been possible without the continued support of the BC Government's Climate Related Monitoring Program. This program is facilitated by an agreement that allows observing network operators across British Columbia to collaborate on network operation and data sharing. It also provides PCIC with a mandate to make these shared data available through the BC meteorological station data portal.
About the Canada Mosaic dataset
Building on the strengths of PRISM as a high-resolution representation of BC's climate, PCIC developed a set of Canada-wide, gridded climatologies at high spatial resolution. These datasets include daily maximum and minimum temperature, as well as total daily precipitation, for the 1981-2010 period. The dataset was created by combining several existing high-resolution climatologies that cover different regions of the country, as illustrated in the figure and table below.
Across most of BC, the mosaic climatologies are identical to the 1981-2010 BC PRISM climatologies. The methodology used to assemble the mosaic is described in Dah, Curry & Zwiers (2026), which also presents a detailed evaluation of the mosaic against available station data. While the mosaics do not capture all features observed in station data, they nevertheless provide a valuable, spatially continuous source of climate information over Canada, which can be used for a host of applications.
| Product | US-PRISM | BC-PRISM | Wcan-PRISM | Daymet | ERA5-Land |
|---|---|---|---|---|---|
| Time period | 1981-2010 | 1981-2010 | 1961-1990 | 1980-2023 | 1950-present |
| Time scale | Monthly climatologies | Monthly climatologies | Monthly climatologies | Daily weather estimates | Daily weather estimates |
| Units | °C, mm/month | °C, mm/month | °C, mm/month | °C, mm/day | °C, mm/day |
| Domain | Contiguous US, Alaska | British Columbia | YK, BC, AB, SK, MB | Continental North America | Continental North America |
| Resolution | ~800m (30 arcsec) |
~800m (30 arcsec) |
Provided at 2km (native: 4km) | 1km (45 arcsec) |
~10km (6.25 arcmin) |
| Source | PRISM Climate Group, OSU (Daly et al., 2008) |
PCIC (PCIC & the PRISM Climate Group OSU, 2014) |
PRISM Climate Group, OSU (Daly et al., 2008) |
Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC) (Thornton et al., 2020) |
Copernicus Climate Change Service (C3S) (Muñoz-Sabater et al., 2021) |
| Original method | Climate-elevation regression using weighted station data (“PRISM method”) | PRISM method with some regionally specific adjustments | PRISM method | Weighted multivariate regression model to estimate spatial gradients in 3 dimensions from station data | Forced land surface model with ERA5 atmospheric reanalysis product |
| Modifications for mosaic | None | None | Climate imprint method to transform the 1961-1990 climate normals to 1981-2010 | None | None |
Please cite the Canada Mosaic dataset as:
- Pacific Climate Impacts Consortium, University of Victoria (2026). Canada-wide Mosaic of Monthly Climatologies. Downloaded from <Permalink> on <Date>.
Data disclaimer
This data has been obtained from a variety of sources and is provided as a public service by the Pacific Climate Impacts Consortium. The data is provided by PCIC on an “AS IS” basis 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 is strictly at your own risk. In no event will PCIC 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.
In addition to PCIC's terms of use, the data are subject to the terms of use for the individual data products comprising the mosaic.