Frequently Asked Questions

Q1. How do I find historical weather data for location 'x' on date 'y'?

A. To view historical weather data for a particular location and date, visit our Historical Data page. You will then be presented with 3 different search methods; by station name, by province or territory, and by proximity. The most commonly used is by station name. If you leave the default setting for these searches, the results will provide you with a list of all stations (historical and current) for the province/location/area you are requesting. Once you have reached the results, you can select the date and data interval and click on "Go" to view the data. Note that data are available in hourly, daily, and monthly intervals. Also note that all three data intervals may not be available for all possible stations; it depends on what was observed at each site.

Q2. Are data available in an easily downloadable file?

A. Data from our Historical Climate Data pages can be downloaded as XML or as a CSV (comma delimited) file by selecting the “Download Data” button located above any data table you are viewing. Hourly data can be downloaded for a period of 1 month at a time, daily data for a period of 1 year at a time, and monthly data for the entire period of record where available. With appropriate IT support, it is possible to automate the download of climate data using Get More Data.

Alternatively, for larger sets of data, an order for a customized dataset can be placed through Climate Services. A cost recovery service charge will apply. To place an order, please contact the Climate Services office within the region of your location of interest. Contact information for all offices can be found within the “Contacts” page.

Q3. How can I download data from multiple stations at a time?

A. Information on this website is posted on a site-by-site basis. For a dataset that contains data for multiple stations at once, you will be required to order a customized dataset from the Climate Services office within the region of your location of interest. Contact information for all offices can be found within the “Contacts” page. Alternatively, with appropriate IT support, it is possible to automate the download of climate data using Get More Data.

Q4. Where can I get values that are missing or left blank online?

A. If values are missing online, this would imply that they are not available. The reasons for missing data are many. In most instances, data values are blank because they had not been observed or transmitted. When a value is flagged as “M” (missing), the data value is not available and cannot be retrieved. If data seems to stop a few months to a few years from the current date, it may imply either that the station has since closed down, or that data is currently being processed through quality control and there is a back-log. If you require specific information for a particular site and date, you can verify this information by contacting the Climate Services office within the region of your location of interest. Contact information for all offices can be found within the “Contacts” page.

Q5. What do the "NA" (not available) values in the hourly weather report represent?

A. In a Historical Climate hourly weather report, if the station operator is NAVCAN, in the column “Weather” “NA” represents no special weather elements reported. If the station operator is ECCC-MSC, in the column “Weather” “NA” represents the weather element is not available.

Q6. What data are available from the National Climate Archives?

A. The National Climate Archives contain a wide variety of Canadian historical weather and climate data. Numerous datasets and products are freely available online. Visit the Historical Climate Data page for a list of all the datasets, products and services that we have to offer.

There are other observations that are not available online, and can only be obtained by order of a cost-recovered customized dataset. Please refer to our “Technical Documentation” for detailed information on all parameters stored in the National Climate Archives.

To obtain more information or to order a customized dataset, please contact the Climate Services office within the region of your location of interest. Contact information for all offices can be found within the “Contacts” page.

Q7. What type of climate should I expect for a Canadian city that I would like to visit?

A. Typical weather conditions for various locations across Canada can be referenced through our Climate Normals datasets. The values presented as Normals on our site provide monthly averages calculated over a 30 year period for stations that contain at least 15 years worth of data. To access this information, click on the Canadian Climate Normals link within the main menu Canadian Climate Normals page, and follow the steps listed.

Q8. Where can I find daily averages?

A. Average temperature and precipitation values for a particular day are provided on the Almanac Averages & Extremes page. Steps on how to obtain the data are also provided.

Q9. Where can I get official/certified documentation for legal purposes?

A. Certified documentation can be requested through the Climate Services office within the region of your location of interest. Contact information for all offices can be found within the “Contacts” page. Note that there is a service charge for the provision of these documents.

Q10. Where can I acquire Engineering Services such as IDF data, National Building Code Design Data, Water Balances/Budgets?

A. Inquiries regarding engineering products and services can be sent to the Engineering Climate Services Unit at scg-ecs@ec.gc.ca.

Certain products are also available on the Engineering Climate Datasets page.

Q11. Are there any GIS formatted data available?

A. GIS formatted data is not provided through the National Climate Archives however our database contains latitude and longitude of each observation (Degrees & minutes) that can be used to create a GIS shape file. The station coordinates are available from the station inventory file download from Get More Data.

Q12. Why is there a charge for the provision of customized datasets and various resources?

A. The reason why charges are applied to specialized services is because Environment and Climate Change Canada, like all government departments, has limited resources. Taxes pay for the collection of weather data that is used for the general good of all Canadians and is incorporated into a variety of products including public forecasts and weather warnings. We do make available as much of our data as possible for download through our website at no charge. Of course, due to bandwidth limitations, we have to limit the amount of data that can be selected at any one time in order to not overload our servers. What are not covered by taxes are specialized extractions or reformatted data to meet the specific requirements of a client. In these cases we must charge for the time taken to do the work, the data itself is free.

Q13. I noticed questionable data on Climate Data Online, what should I do?

A. To report questionable data, please send a detailed message to the Climate Services office within the region of your location of interest. Contact information for all offices can be found within the “Contacts” page.

Q14. Is the information from the Climate Data Online Website legal in court?

A. Whether information from the Climate Data Online Website is admissible in court will depend upon the nature of the proceeding and the purpose for which the data is produced. Data taken from the Climate Data Online Website may be admissible in court without certification by Environment and Climate Change Canada. If certification of the data by Environment and Climate Change Canada is required, the Climate Service offices can supply that information at a nominal cost. The list of Climate Service Offices and their contact information is available within the “Contacts” page.

Q15. Why is it that if a climate station reports daily total precipitation, the hourly precipitation amount column is empty? Example: Toronto Intl A on January 2021.

A. This is because the element 262 was selected to be displayed as precipitation amount in hourly reports. Since Toronto Intl A on January 2021 did not have hourly element 262 data in the archive, the hourly precipitation data for those days in Toronto Intl is not displayed on the webpage.

Q16. On the “Monthly Climate Summaries” web page, when it says “Data sets are updated on the 5^th of the month” – this means November data will be available on December 5, for example? Are there ever any revisions to these data? Or once a month is released it remains the same?

A. Yes, the data sets are updated on the 5^th of the month, and this means November data should be available on December 5^th. The Monthly Climate Summaries are updated daily – as data corrections come in, they trigger updates to the database tables that feed to the CDO Monthly Climate Summary data.

Q17. Can you tell me approximately what time of day the previous day's Daily Data is made available within the Historical Data section?

A. Calculations of daily values will occur twice during the day at 1000UTC and 1900UTC. The first run at 1000UTC will occur for all stations. The second run at 1900UTC will occur only for stations with late arriving values for that day and stations that have undergone hourly corrections in the MSC Archive QC tool.

Q18. How should I reference data?

A. For data retrieved from the Historical Climate Data web site :

“Extracted from the Environment and Climate Change Canada Historical Climate Data web site (https://climate.weather.gc.ca/index_e.html) on [DATE]”.

Q19. What is a DPQPE radar product?

A. DPQPE stands for: Dual-Pol Quantitative Precipitation Estimation. The DPQPE product is available only for S-Band radars. It is a two-dimensional representation of the precipitation rate estimated by the lowest sweep of the radar (elevation angle of 0.4 degrees for the majority of S-Band radars). Thus, the precipitation rate is estimated as close to the earth's surface as possible. The DPQPE product is based, among other things, on a series of polarimetric processing steps (quality control) to eliminate non-meteorological artifacts from the raw data (volumetric scans). It renders in mm/h for rain and cm/h for snow. This product is calculated with a maximum coverage range of 240 km.

For more information about the Canadian Weather Radar.