Below is a library of all variables available within ClimateData.ca. Use the filter to limit your search to specific types of data.
Relative Sea Level Change is the change in ocean level relative to land. Whereas global sea-level change can be attributed to thermal expansion of water and meltwater from glaciers, ice caps, and ice sheets, relative sea-level change is the combination of the effects from global sea-level change and the vertical motion of the land.
CMIP6 projected relative sea level change data is available for every decade from 2020-2100, relative to 1994-2015 conditions.
CMIP5 projected relative sea level change data is available for 2006 and for every decade from 2010-2100, relative to 1986-2005 conditions.
Read more
Projections of Relative Sea-Level Change (developed by Natural Resources Canada)
To help Canadians plan, prepare for, and remain resilient to projected sea-level changes, Natural Resources Canada (NRCan) has developed a new dataset of present and future relative sea-levels (James et al., 2021). The dataset provides projections for relative sea-level change, which is the change in ocean height relative to land and is the apparent sea-level change experienced by coastal communities and ecosystems. It is a combined measure of both changes to ocean levels due to climate change and vertical land movements, as described below.
Projections are available at a resolution of 0.1° (approximately 11 km latitude, 2-8 km longitude), and for 2006 and every decade from 2010-2100, relative to 1986-2005 conditions.
For CMIP6, projections are relative to 1994-2015 conditions and the data is available for four Shared Socio-economic Pathway (SSP) emissions scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5) and two enhanced scenarios.
For CMIP5, projections are relative to 1986-2005 conditions and data is available for three Representative Concentration Pathways (RCP) emissions scenarios (RCP 2.6, RCP 4.5, RCP 8.5) and an enhanced scenario.
Use relative sea-level rise data together with other types of data
When combined with other types of data such as estimates of storm surge, waves, tides, and additional local-scale vertical land motion, such as subsidence on river deltas, this relative sea-level data is expected to contribute significantly to coastal flood risk assessments and adaptation decision-making.
Relative sea-level change varies greatly based on where you live in Canada
Relative sea-level change along Canada’s coastlines varies greatly from location to location, and can differ substantially from the projected global average sea-level change. Some Canadian coastlines in Atlantic Canada can expect relative sea-level rise that is larger than the projected global sea-level rise. Conversely, other Canadian coastlines, where the land is rising faster than the ocean, such as Hudson Bay and much of the Canadian Arctic Archipelago, can expect a relative sea-level fall.
Guidance on emissions scenarios
CMIP6
Data estimates are available for four emissions scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5) as reported in the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR6). For each scenario, lower, median and upper estimates of projected relative sea-level change are provided, corresponding to the 17th, 50th and 83rd percentiles of the full ensemble of global climate models. Two additional enhanced scenarios are also available, described below. All projections are based on open ocean basin changes that are extrapolated to the coastline (which does not include explicit modelling of shallow water effects).
Two low-probability, high-impact storylines are also provided. The first is based on CMIP6 low-confidence projections that incorporate additional information on Antarctic Ice Sheet stability. The storyline projection lies above the upper envelope of the SSP5-8.5 scenario. The second is based on an approach from Van de Wal et al, (2022) that was co-developed by scientists and practitioners by combining physical evidence and approaches currently used in policy environments. This scenario is equivalent to the 98.33rd percentile of the medium confidence projections. These two storylines can be accessed via the time series plots that users receive when selecting a gridcell on the map.
CMIP5
Data estimates are available for three RCP scenarios: RCP 2.6 (low), RCP 4.5 (medium), and RCP 8.5 (high) – as reported in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5; Church et al, 2013a,b). For each scenario, lower, median and upper estimates of projected relative sea-level change are provided, corresponding to the 5th, 50th and 95th percentiles of the full ensemble of Global Climate Models. An additional Enhanced Scenario is also available, described below. All projections are based on open ocean basin changes that are extrapolated to the coastline (which does not include explicit modelling of shallow water effects).
In the case of low tolerance to risk and for project time frames extending past 2100, it would be prudent to consider the enhanced scenario described below. The enhanced scenario adds a further 65 cm of global sea-level rise to the median projection of the highest (RCP8.5) climate scenario at 2100. This 65 cm reflects a potential additional contribution from the Antarctic Ice Sheet.
For long-term decisions that may be influenced by sea-level changes, the precautionary principle would indicate using the upper end of the highest emissions scenario. In the case of very low tolerance to risk and for long project timeframes, it may be appropriate to consider the storylines mentioned above. In other situations, the use of higher or lower sea-level values, or a range of projected sea-level change, may be more appropriate.
For detailed technical guidance on the use of sea-level projections see Relative sea-level projections for Canada based on the IPCC Fifth Assessment Report and the NAD83v70VG national crustal velocity model (James et al, 2021) and GEOSCAN for the full publication and data.
More about this dataset
Projected sea-level changes in this dataset include the effects of changes in glacier and ice-sheet mass loss, thermal expansion of the oceans, changing ocean circulation conditions, and human-caused changes in land water storage, as summarized in IPCC AR6. A new land motion model developed by the Canadian Geodetic Survey (Robin et al., 2020; Canadian Geodetic Survey, 2019) was incorporated into the data to replace less-accurate land motion values utilized by the IPCC AR6.
Vertical land movements in Canada largely result from loading and unloading of the Earth’s surface by ice sheets. During the last ice age that ended about seven thousand years ago, much of Canada was covered with thick ice sheets that weighed down the surface of the Earth. Deep within the Earth, rock yielded and flowed and the land under the ice was pushed down. At the edges of the ice sheets, the land was pushed up. Following the thinning and retreat of those ice sheets, land that was pushed down started to rise, while land that was uplifted began to sink, a process that continues to the present day. Tectonic effects causing earthquakes and land subsidence caused by sediment compaction on coastal deltas can also generate vertical movements that contribute to relative sea-level change, but these are not accounted for in these projections.
It should be noted that the crustal velocity model used for the Relative Sea-Level Change data available on ClimateData.ca is based on measurements of land motion made on bedrock. Therefore, local subsidence and compaction effects in locations with a thick sequence of unconsolidated sediment, i.e. large deltas such as those at the mouth of the Fraser and Mackenzie rivers (James et al, 2021), are not reflected in the crustal velocity model. Consequently, the sea-level projections in such locations should be adjusted to incorporate, if available, local knowledge of vertical land motions. For this reason, the Vertical Land Motion data from the crustal velocity model used for this dataset is provided. This will allow users to remove the effects of vertical land motions as calculated in the crustal velocity model from the sea level data found on ClimateData.ca with a view to replace it with values based on other sources of local knowledge of vertical land motion.
References
Vertical Allowance (CMIP6) – developed by the Department of Fisheries and Oceans (DFO).
The vertical allowance dataset presents values for coastal infrastructure over much of Canada’s coastline. Projections provided at this scale allow for high-level comparisons and planning. However, they also come with compromises, including the lack of small-scale details that may be important at specific locations. When using vertical allowance for the planning or adapting of coastal infrastructure, it is necessary to consult with coastal engineers who understand the local context in which this variable will be applied (including erosion vulnerability, wave run-up issues, etc.).
Vertical allowance is defined as the amount by which an asset (e.g., building, wharf) should be raised under rising sea levels so that the present frequency of coastal flooding does not increase for a chosen future period (Zhai et al., 2023). These data incorporate current statistics of tides and storm surges, as well as relative sea-level change projections and the uncertainties in those projections.
Projected vertical allowances (in cm) are available at a resolution of 0.1° (approximately 11 km latitude, 4-8 km longitude) for the coasts of British Columbia, Atlantic Canada and eastern Arctic south of 70°N for every decade from 2020-2100, relative to 2010 conditions. Vertical allowances up to 2150 are available upon request. The data are available for four Shared Socio-economic Pathways (SSP) emissions scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP5-8.5).
In the Arctic north of 70°N, the vertical allowance cannot be computed as there is no storm surge model data available.
Read more for methods and more details
Vertical allowance varies greatly based on where you live in Canada
Relative sea-level change, tide, and storm behavior (and the associated change in vertical allowance) along Canada’s coastlines varies greatly from location to location, and can differ substantially from the projected global average change. For example, some Canadian coastlines in Atlantic Canada can expect relative sea-level rise that is larger than the projected global sea-level rise. Conversely, other Canadian coastlines, where the land is rising faster than the ocean, such as Hudson Bay and much of the Canadian Arctic Archipelago, can expect a relative sea-level fall (Greenan et al., 2019; James et al., 2021).
Guidance on emissions scenarios and model uncertainty
Data is available for four Shared Socio-economic Pathways (SSP) emissions scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5).– as reported in the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (Fox-Kemper et al., 2021).
For guidance on the considering uncertainty and the use of these scenarios see Uncertainty in Climate Projections and Understanding Shared Socio-economic Pathways (SSPs).
Methods
Projected sea-level changes in this dataset include the effects of changes in glacier and ice-sheet mass loss, thermal expansion of the oceans, changing ocean circulation conditions, and human-caused changes in land water storage, as summarized in IPCC AR6 (Fox-Kemper et al., 2021). A new land motion model developed by the Canadian Geodetic Survey (Robin et al., 2020; Canadian Geodetic Survey, 2019) was incorporated into the data to improve upon the land motion values utilized by the IPCC AR6.
For more information about the relative sea level change component of vertical allowance, see the relative sea level change variable.
Following (Hunter, 2012), the vertical allowance is defined as:
𝑎 = ∆𝑧 + 𝜎2/2𝜆
where:
∆z is the mean relative sea level projection,
σ is the standard deviation of the relative sea level projections,
and 𝜆 is the scale parameter.
The standard deviation σ is computed as the half range of the 5- to 95-percentile limits of the climate projections multiplied by 0.608 (assuming a normal distribution).
Storm and tide model simulations were used to define the scale parameter. Please see (Zhai et al., 2023) for more details on how these were arrived at.
Use Vertical allowance data together with other types of data
When considering vertical allowance, it is important for coastal engineers to have accurate estimates of present-day water levels referenced to a standard vertical datum. Vertical datum provides a consistent reference for measuring water level. The vertical allowances provided on ClimateData.ca are with respect to Mean Water Level epoch 2010 to the GRS80 ellipsoid in the NAD83(CSRS) reference frame (Zhai et al., 2023). These water level data, using the same ellipsoid and reference frame, have been calculated for all tidal waters of Canada using the Continuous Vertical Datum developed by the Canadian Hydrographic Service (CHS) (Robin et al., 2016). This continuous set of vertical datum will be accessible at a later date for download on the CHS website (this page will be updated once available). Meanwhile, vertical allowance users can access such data available at DFO Small Craft Harbours and CHS tide gauge locations, through the CAN-EWLAT tool developed by DFO: CAN-EWLAT.
Limitations
References
Frost Days describes the number of days where the coldest temperature of the day is lower than 0°C.
The number of frost days is an indicator of the length and severity of the winter season. A location with a large number of frost days is also likely to have a short growing season, since frost is harmful to many plants.
Technical description:
A day when the daily minimum temperature (Tmin) is below 0°C. Use the Variable menu option to view the annual, monthly or seasonal values for this index.
This is a simple count of the days when the air temperature fluctuates between freezing and non-freezing temperatures on the same day. Freeze-thaw cycles can have major impacts on infrastructure. Water expands when it freezes, so the freezing, melting and re-freezing of water can, over time, cause significant damage to roads, sidewalks, and other outdoor structures.
Technical description
A freeze-thaw cycle occurs when the daily maximum temperature (Tmax) is higher than 0°C and the daily minimum temperature (Tmin) is less than or equal to -1°C.
The Variable menu option provides annual values for this index. Visit the Analyze page to calculate this index at different temporal frequencies, or to use different threshold values.
Cooling degree days (CDDs) give an indication of the amount of space cooling, i.e., air conditioning, that may be required to maintain comfortable conditions in a building during warmer months. When the daily average temperature is hotter than the threshold temperature, CDDs are accumulated (see Degree Days Above). Threshold values may vary, but 18°C is commonly used in Canada. Larger CDD values indicate a greater need for air conditioning.
Technical description:
The number of degree days accumulated above 18°C in the selected time period. Use the Variable menu option to view the annual, monthly or seasonal values for this index. Visit the Analyze page to calculate degree days using different threshold temperatures.
Tropical Nights (Days with Tmin >18°C) describes the number of days where the nighttime low temperature is warmer than 18°C.
Hot summer days and heat waves become particularly stressful if overnight temperatures do not provide cooling relief. Tropical nights make it more difficult for the body to cool down and recover from hot days.
Elderly people, the homeless, and those who live in houses or apartments without air conditioning are especially vulnerable during these heat events, particularly if they last for more than a few days.
Technical description:
A Tropical Night occurs when the daily minimum temperature (Tmin) is greater than 18°C. Use the Variable menu option to view the annual, monthly or seasonal values for this index. Visit the Analyze page to calculate Tropical Nights using different minimum temperature thresholds.
Tropical Nights (Days with Tmin >20°C) describes the number of days where the nighttime low temperature is warmer than 20°C.
Hot summer days and heat waves become particularly stressful if overnight temperatures do not provide cooling relief. Tropical nights make it more difficult for the body to cool down and recover from hot days.
Elderly people, the homeless, and those who live in houses or apartments without air conditioning are especially vulnerable during these heat events, particularly if they last for more than a few days.
Technical description:
A Tropical Night occurs when the daily minimum temperature (Tmin) is greater than 20°C. Use the Variable menu option to view the annual, monthly or seasonal values for this index. Visit the Analyze page to calculate Tropical Nights using different minimum temperature thresholds.
Tropical Nights (Days with Tmin >22°C) describes the number of days where the nighttime low temperature is warmer than 22°C. Hot summer days and heat waves become particularly stressful if overnight temperatures do not provide cooling relief. Tropical nights make it more difficult for the body to cool down and recover from hot days.
Elderly people, the homeless, and those who live in houses or apartments without air conditioning are especially vulnerable during these heat events, particularly if they last for more than a few days.
Technical description:
A Tropical Night occurs when the daily minimum temperature (Tmin) is greater than 22°C. Use the Variable menu option to view the annual, monthly or seasonal values for this index. Visit the Analyze page to calculate Tropical Nights using different minimum temperature thresholds.
Growing degree days (GDD) are a measure of whether climate conditions are warm enough to support plant and insect growth. When the daily average temperature is warmer than the threshold temperature, growing degree days are accumulated (see Degree Days Above). For forage crops and canola, a threshold temperature of 5°C is generally used.
Technical description:
The number of degree days accumulated above a threshold temperature of 5°C in the selected time period. Use the Variable menu option to view the annual, monthly or seasonal values for this index. Visit the Analyze page to calculate degree days using different threshold temperatures.
Cumulative degree days above 0°C can be used to determine when climate conditions are warm enough to support the growth of certain plants and pests. When the daily average temperature is warmer than 0°C, degree days are accumulated (see Degree Days Above).
This index can be used to determine the range of some insects and other pests. For example, the black-legged tick, which carries Lyme disease, requires the accumulation of at least 2800 degree days above 0°C for its survival. Warmer conditions can speed the development rate of these species and lead to an extension of their geographical range.
Technical description:
The number of degree days accumulated above 0°C in the selected time period. Use the Variable menu option to view the annual, monthly or seasonal values for this index. Visit the Analyze page to calculate degree days using different threshold temperatures.
Heating degree days (HDDs) give an indication of the amount of space heating (e.g., from a gas boiler/furnace, baseboard electric heating or fireplace) that may be required to maintain comfortable conditions inside a building during cooler months. When the daily average temperature is colder than the threshold temperature, HDDs are accumulated (see Degree Days Below). Threshold values may vary, but 17°C or 18°C are commonly used in Canada. Larger HDD values indicate a greater need for space heating.
Technical description:
The number of degree days accumulated below 18°C in the selected time period. Use the Variable menu option to view the annual, monthly or seasonal values for this index. Visit the Analyze page to calculate degree days using different threshold temperatures.
Climate Zones for buildings are determined based on the unique climatic conditions of a particular region. The National Energy Code of Canada for Buildings (NECB) uses Heating Degree Days to define Climate Zones. In this case, Heating Degree Days (HDDs) are calculated using a threshold of 18°C. This metric indicates the potential heating required to maintain comfortable conditions inside a building.
Because the climate is changing, relying on historical data is no longer adequate and information about future climate is also required to design future-ready buildings.
Technical Description:
The NECB Climate Zones are classified based on the number of HDDs. The thresholds are shown in the table below. Additional guidance about Climate Zones for buildings can be found on the Learning Zone.
NECB’s Building Climate Zone Classifications for Canada.
| Zone | Heating Degree-Days of Building Location Celsius Degree-Days |
|---|---|
| 4 | < 3000 |
| 5 | 3000 to 3999 |
| 6 | 4000 to 4999 |
| 7A | 5000 to 5999 |
| 7B | 6000 to 6999 |
| 8 | ≥ 7000 |
Ice Days describe the number of days where the warmest temperature of the day is not above 0°C.
In other words, this index indicates the number of days when temperatures have remained below freezing for the entire 24-hour period. This index is an indicator of the length and severity of the winter season.
Technical description:
A day when the daily maximum temperature (Tmax) is less than 0°C. Use the Variable menu option to view the annual, monthly or seasonal values for this index.