Type TIF
This group layer, prepared by the Commission for Environmental Cooperation (CEC), brings together 12 monthly temperature layers for North America covering the 1981–2010 climatological reference period, in degrees Celsius, one for each month of the year. The layers represent mean monthly temperature values derived from the CHELSA climate downscaling model, and were processed and harmonized for integration with the map layers of the CEC North American Environmental Atlas.
This group layer, prepared by the Commission for Environmental Cooperation (CEC), contains 12 raster layers (one per month) representing mean monthly temperature values across North America for the 1981–2010 climatological reference period, in degrees Celsius. The layers are derived from a kilometer-scale climate product generated using the CHELSA downscaling model and represent long-term climatological means.
The North American monthly temperature layers were derived from the CHELSA Climatologies v2.1 dataset, which is based on statistically downscaled temperature and precipitation data at a spatial resolution of 30 arc-seconds (~1 km). CHELSA (Climatologies at High Resolution for the Earth's Land Surface Areas) applies a statistical downscaling approach to atmospheric temperature fields to produce high-resolution climate surfaces.
Additional technical details on the downscaling methodology and derived climate predictors are provided in: Karger, D. N., Conrad, O., Böhner, J., Kawohl, T., Kreft, H., Soria-Auza, R. W., Zimmermann, N. E., Linder, H. P., & Kessler, M. (2017). Climatologies at high resolution for the Earth's land surface areas. Scientific Data, 4, 170122. https://doi.org/10.1038/sdata.2017.122
Geographic Coverage
The coverage spans North America, including Canada, Mexico, and the United States.
Data Sources and Licensing
Commission for Environmental Cooperation (CEC). Swiss Federal Institute for Forest, Snow and Landscape Research (WSL). Karger et al. (2017). The data is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0), allowing redistribution and adaptation with appropriate attribution.
Update frequency: Irregular
Limitations of use: None. Acknowledgment of the Commission for Environmental Cooperation and the (CHELSA) initiative at the Swiss Federal Research Institute WSL (Land Change Science group) would be appreciated in products derived from these data.
Vintage: 1981-2010
Applications (Intended Use)
* Analyzing spatial and seasonal patterns of monthly temperature across North America.
* Supporting climate, hydrological, and water-resource research and planning.
* Informing agricultural and ecological modeling and land-use planning.
* Integration with other thematic layers in the North American Environmental Atlas for continental-scale analysis.
* Supporting environmental cooperation and policy-making among Canada, Mexico, and the United States.
Commission for Environmental Cooperation (CEC). 2026. “North American Environmental Atlas - Monthly Temperature, 1981-2010”. Swiss Federal Institute for Forest, Snow and Landscape Research (WSL). Ed. 2.0, Raster digital data [1-km].
None. Acknowledgment of the Commission for Environmental Cooperation and the (CHELSA) initiative at the Swiss Federal Research Institute WSL (Land Change Science group) would be appreciated in products derived from these data.
| West | -180 | East | -50 |
| North | 85 | South | 14 |
| Maximum (zoomed in) | 1:5,000 |
| Minimum (zoomed out) | 1:150,000,000 |
Contact Person: Dirk Nikolaus Karger
The Commission for Environmental Cooperation (CEC) is an international organization created by Canada, Mexico, and the United States of America under the North American Agreement on Environmental Cooperation (NAAEC), which came into force at the same time as the North American Free Trade Agreement (NAFTA). The CEC was established to address regional environmental concerns, help prevent potential trade and environmental conflicts, and to promote the effective enforcement of environmental law. As of 2020, the CEC operates in accordance with the Environmental Cooperation Agreement, which entered into force at the same time as the CUSMA/T-MEC/USMCA trade agreement. Additional information on the CHELSA Climatologies v2.1 dataset used to produce the CEC North American climatological map layers is available in: Karger, D. N., Conrad, O., Böhner, J., Kawohl, T., Kreft, H., Soria-Auza, R. W., Zimmermann, N. E., Linder, H. P., & Kessler, M. (2017). Climatologies at high resolution for the Earth’s land surface areas. Scientific Data, 4, 170122. https://doi.org/10.1038/sdata.2017.122 This data set is available in several formats, including TIF, Map package, and a PDF Map, along with other files appropriate to particular formats, such as .lyrx and .qlr files.
Commission for Environmental Cooperation (CEC). 2026. “North American Environmental Atlas - Monthly Temperature, 1981-2010”. Swiss Federal Institute for Forest, Snow and Landscape Research (WSL). Ed. 2.0, Raster digital data [1-km].
North America
None. Acknowledgment of the Commission for Environmental Cooperation and the (CHELSA) initiative at the Swiss Federal Research Institute WSL (Land Change Science group) would be appreciated in products derived from these data.
This material is licensed under CC BY 4.0, allowing non-exclusive rights to distribute, remix, adapt, and build upon the material in any medium or format, including for commercial purposes, so long as attribution is given to the creator.
A spatial completeness assessment was conducted after extracting the North American extent and reprojecting the CHELSA Climatologies v2.1 monthly raster layers derived from daily mean near-surface air temperature (tas) to the standard Lambert Azimuthal Equal Area projection used by the Atlas. The dataset was inspected for NoData values, edge artifacts, and potential cell misalignment introduced during reprojection. Cell counts and value ranges were verified to ensure that no unintended data loss or omissions occurred. The final raster exhibits continuous coverage across the defined terrestrial extent, with NoData values restricted to areas outside the land mask.
The raster maintains consistent cell size, alignment, and spatial continuity following clipping and reprojection. No unintended gaps, overlaps, or resampling artifacts were introduced during processing.
The North American monthly temperature layers were derived from the CHELSA Climatologies v2.1 dataset, which is based on statistically downscaled temperature and precipitation data at a spatial resolution of 30 arc-seconds (~1 km). CHELSA (Climatologies at High Resolution for the Earth’s Land Surface Areas) applies a statistical downscaling approach to atmospheric temperature fields to produce high-resolution climate surfaces. For the North American Environmental Atlas, the continental subset was extracted from the global dataset and reprojected to the standard Lambert Azimuthal Equal Area projection used by the Atlas. Additional technical details on the downscaling methodology and derived climate predictors are provided in: Karger, D. N., Conrad, O., Böhner, J., Kawohl, T., Kreft, H., Soria-Auza, R. W., Zimmermann, N. E., Linder, H. P., & Kessler, M. (2017). Climatologies at high resolution for the Earth’s land surface areas. Scientific Data, 4, 170122. https://doi.org/10.1038/sdata.2017.122
Each CHELSA Climatologies v2.1 monthly temperature raster layer, derived from daily mean near-surface air temperature (tas) for the 1981–2010 period, was clipped to the North American region using the CEC North American Political Boundaries vector dataset. The clipping was performed using the Extract by Mask tool in ArcGIS Pro. During this process, the raster was reprojected to the Lambert Azimuthal Equal Area projection, the standard coordinate reference system used by the CEC North American Environmental Atlas. The data were resampled from the original ~30 arc-second (~1 km) resolution to a 1 km cell size and aligned with Version 1.0 of the CEC North American Mean Annual Temperature raster layer to ensure consistency in grid structure and spatial resolution.
In each monthly raster layer, pixel values were converted from scaled Kelvin to degrees Celsius according to the scale factor and offset specified in the CHELSA Climatologies technical documentation. The transformation was performed by multiplying the raster values by 0.1 (scale factor) and subtracting 273.15 to convert from Kelvin to Celsius. This conversion was implemented using the Raster Calculator tool in ArcGIS Pro.
The final monthly raster layers were exported in GeoTIFF format using a 32-bit floating-point pixel type to maintain decimal precision after unit conversion.
CHELSA-climatologies is a global, kilometer-scale climate dataset generated with the CHELSA downscaling model. It consists of long term climatological means.
~30 arcsecond resolution
Contact Person: Dirk Nikolaus Karger
The Political Boundaries dataset of the North American Environmental Atlas represents political entities in North America as polygons.
The Mean Monthly Temperature (january) data set is a raster file showing values derived from mean monthly temperature readings. The source data covers the years 1950-2000; individual weather stations used to supply the source data may not have data available for all the years.
1000 meters resolution
None. Acknowledgment of the Commission for Environmental Cooperation and the (CHELSA) initiative at the Swiss Federal Research Institute WSL (Land Change Science group) would be appreciated in products derived from these data.
This material is licensed under CC BY 4.0, allowing non-exclusive rights to distribute, remix, adapt, and build upon the material in any medium or format, including for commercial purposes, so long as attribution is given to the creator.