ClimateBC Map Version


Tongli Wang

Centre for Forest ConservationGenetics (CFCG)

Department of Forest Science, University of British Columbia


Andreas Hamann

Department of Renewable Resources, University of Alberta, Edmonton


Dave Spittlehouse

Competitiveness and Innovation Branch, Ministry of Forests, Lands and Natural Resource Operations,

British Columbia, Canada


April 10, 2012, 2012



About this program.. 1

Features. 2

How to use. 3

Climate variables. 3

Overlays. 4

Climate maps. 4

BEC zones. 4

Species range maps. 5

Seed Planning Units (SPUs) 5

How to refer. 5

Acknowledgements. 5


About this program


ClimateBC_Map is a Google map based version of the standalone MS Windows ClimateBC v4.70. It extracts and downscales PRISM 1961-1990 monthly normal data (2.5 x 2.5 arcmin) to scale-free and calculates seasonal and annual climate variables for specific locations based on latitude, longitude and elevation (optional). The coverage of ClimateBC includes British Columbia only (Figure 1). The program uses the scale-free data as baseline in combination with monthly variability data (Mitchell and Jones 2005) of individual years to calculate historical monthly, seasonal and annual climate variables for individual years between 1901-2002. This program also downscales and integrates future climate datasets for 2020s (2010-2039), 2050s (2040-69) and 2080s (2070-2099) generated by several commonly used global circulation models (GCM). The output of the program includes both directly calculated and derived climate variables. Downscaling of PRISM monthly data including bilinear interpolation and elevation adjustment, and calculation of climate variables and estimation of derived climate variables are described in Wang et al. (2006) and Hamann and Wang (2005). For predictions of multiple locations and for more GCMs, we recommend you to download the standalone version at http://genetics.forestry.ubc.ca/cfgc/climate-models.html.


ClimateBC_Map includes various overlays to help users to identify the locations of interest. Meanwhile, it also serves as a web platform to host spatial data generated from related climate change studies for easy access. The overlays include climate maps, Biogeoclimatic Ecosystem Classification (BEC) zones, species ranges and Seed Planning Units (SPUs).



Figure 1. The coverage of ClimateBC.



1.      Automatic import of coordinates: Latitude, longitude and elevation can be automatically imported by clicking on the map. The values of latitude and longitude are generated by Google Map geo-positioning system, while the elevation is based on USGS GTOPO30 (Global 30 Arc Second Elevation Data Set), which is at the resolution approximately 1000 meter. Alternatively, latitude, longitude and elevation can be input manually.

2.      Navigate the map with overlays to identify the locations of interest. The overlays include climate variables, BC Biogeoclimatic ecosystem classifications (BEC), tree species ranges and Seed Planning Units (SPUs) for current and future (still in process).

3.      Covering a historical period of 1901- 2009. The following climate variables can be generated for either a historical period (a year or a period) or a climate change scenario.

4.      Save outputs for multiple locations to a file on your local computer.


How to use

Please check the Quick Tutorial.


Climate variables

1)      Annual variables:

Directly calculated variables:

MAT mean annual temperature (C),

MWMT mean warmest month temperature (C),

MCMT mean coldest month temperature (C),

TD temperature difference between MWMT and MCMT, or continentality (C),

MAP mean annual precipitation (mm),

MSP mean annual summer (May to September) precipitation (mm),

AHM annual heat:moisture index (MAT+10)/(MAP/1000))

SHM summer heat:moisture index ((MWMT)/(MSP/1000))

Derived variables:

DD<0 degree-days below 0C, chilling degree-days

DD>5 degree-days above 5C, growing degree-days

DD5100 the Julian date on which DD>5 reaches 100, the date of budburst for most plants

DD<18 degree-days below 18C, heating degree-days

DD>18 degree-days above 18C, cooling degree-days

NFFD the number of frost-free days

FFP frost-free period

bFFP the Julian date on which FFP begins

eFFP the Julian date on which FFP ends

PAS precipitation as snow (mm)

EMT extreme minimum temperature over 30 years

Eref Hargreaves reference evaporation

CMD Hargreaves climatic moisture deficit


2) Seasonal variables:

Tave(12-2) winter mean temperature (C)

Tave(3-5) spring mean temperature (C)

Tave(6-8) summer mean temperature (C)

Tave(9-11) autumn mean temperature (C)


Tmax(12-2) winter mean maximum temperature (C)

Tmax(3-5) spring mean maximum temperature (C)

Tmax(6-8) summer mean maximum temperature (C)

Tmax(9-11) autumn mean maximum temperature (C)


Tmin(12-2) winter mean minimum temperature (C)

Tmin(3-5) spring mean minimum temperature (C)

Tmin(6-8) summer mean minimum temperature (C)

Tmin(9-11) autumn mean minimum temperature (C)


PPT(12-2) winter precipitation (mm)

PPT(3-5) spring precipitation (mm)

PPT(6-8) summer precipitation (mm)

PPT(9-11) autumn precipitation (mm)


3) Monthly variables

Tave(1) Tave(12) January - December mean temperatures (C)

Tmax(1) Tmax(12) January - December maximum mean temperatures (C)

Tmin(1) Tmin(12) January - December minimum mean temperatures (C)

PPT(1) PPT(12) January - December precipitation (mm)


Climate maps

Climate data were produced by ClimateWNA desktop version at the resolution of 0.08333 arcminute (about 800 meters). Overlay maps and raster layers (TIF) were generated in ArcGIS Desktop version 10. The projection of the raster layers is World Geodetic System (WGS84).

For future climate change scenarios, only one scenario has been added (more will be added) from The Third Generation Coupled Global Climate Model from Canadian Centre for Climate Modelling and Analysis: CGCM3 A2 run4

BEC zones

The maps were generated based on digital map of the BEC version 7 from Biogeoclimatic Ecosystem Classification (BEC) and Ecology Research program of the British Columbia at http://www.for.gov.bc.ca/hre/becweb/. Future projections for the ecosystem climate niches (Flying BEC zones) are consensus projections based on 20 climate change scenarios (Wang et al. 2012).


Species range maps

Species maps were generated based on species crown cover (%) observed in the ecological plots and averaged over each BEC variant (Hamann and Smets 2005). Due to limitations of the ecological plot data and the average effect over the BEC variant, the species range maps may not exactly match with the actual species range on the ground in some areas. More tree species and the shifts in their climate envelopes will be added later on.


Seed Planning Units (SPUs)

Seed Planning Units (SPUs) are the new organisational units that form the basis for breeding and seed production planning. They are organised by species, seed planning zone, and elevation band. SPU version 3.2 is used, which is before the upward elevation adjustment for climate change. It is because this version is used as the basis for projection of future SPUs (not posted yet). More information about SPUs is available at: http://www.for.gov.bc.ca/hti/speciesplan/index.htm.

Note: Upward elevation changes to Seed Planning Units (SPU) were made in November 2008 (effective April, 2009) as amendments to the Chief Forester Standards for Seed Use.  For more information, see  SPU Upward Elevation Changes,  Maps and Spatial Data and DataBC Geographic Services.



How to refer


Wang, T., A. Hamann, D. L. Spittlehouse, and T. Murdock. 2012. ClimateWNA - High-Resolution Spatial Climate Data for Western North America. Journal of Applied Meteorology and Climatology 51: 16-29

Wang, T., Campbell, E.M., O'Neill, G.A., Aitken, S.N., 2012. Projecting future distributions of ecosystem climate niches: uncertainties and management applications. Forest Ecology and Management, in press.

Wang, T., A. Hamann, D.L. Spittlehouse and S.N. Aitken. 2006. Development of scale-free climate data for western Canada for use in resource management. Intl. J. Climatology, 26(3):383-397




Funding for this study was provided by the Forest Investment Account through both the BC Forest Science Program and the Forest Genetics Council of BC and Future Forest Ecosystem Scientific Council (FFESC).