How do I obtain historical weather data for a specific location in Canada?

1. How do I obtain historical weather data using the Map interface (e.g. for White Rock, British Columbia)?

On the Climate Data Online page, there is an interactive map of Canada. Many of the major Canadian cities are labelled on this map. By clicking on one of these major cities, such as Toronto, climate data pertaining to one popular station in the city is displayed, e.g. Toronto Lester B. Pearson Int'l A. Please note that other stations may be available for these major cities and can be identified by using the Customized Search tool described below. Prior to selecting a city, the Data Interval must be set in the Search Options box located in the upper right hand side of the map of Canada. A detailed description of the different data intervals can be found in the glossary.

There are two methods of obtaining historical data for a location that is not indicated on the map (e.g. White Rock, British Columbia) using the interactive map of Canada. In the first method, you may scroll the mouse over top of any province or territory, e.g. British Columbia, and select it by double clicking on it. A more detailed map of British Columbia now appears. Many more cities are highlighted on this map and data from these stations can be found using the same method as described above for Toronto. The other option is to use the drop down menu, above the map, labelled Province and select British Columbia. This takes you to the same provincial map where any city may be selected by clicking on it. You may also select the city by using the dropdown menu, above the map of British Columbia, labelled City.

It is clear from the provincial map and the dropdown City menu that White Rock, British Columbia cannot be easily found. If the location you are looking for is not available on the provincial map you may have to use the Customized Search option described below.

2. How do I obtain historical weather data using the Customized Search (e.g. for White Rock, British Columbia)?

Just above the map of Canada, click on the Customized Search button. You will be presented with three different search methods; i) Search by Province, ii) Search by Station Name and, iii) Search by Proximity. In the second option, Search by Station Name, enter the name of the location you are searching for (e.g. White Rock) and click on Search.

You will be taken to a page with a list of all the stations that have all of the criteria that you have specified in your search, if any exist. If no stations are found, you can also use the Search by Province method to view a list of all the stations with available data in any province or territory.

For the station that you are interested in, select a year, month and day. Selecting Hourly in the data interval will give you weather conditions for every hour including temperature, humidity and wind information, where available for a specified day. Selecting Daily in the data interval will give you information about the maximum and minimum temperature, amount of precipitation (rain/snow), maximum wind gust and more, where available, for every day of the selected month. Selecting Monthly in the data interval will give you the monthly totals (this section is often not up-to-date by several months due to a longer quality control process) for a specified year. Finally, you can also select Almanac in the data interval to get daily averages and extremes.

For example: select White Rock Campbell Scientific in B.C., select the "Daily" Data Interval for November 10th, 2004 and press Go. You will find that on November 10th, 2004 the maximum temperature in White Rock, B.C. was 14.2°C, the minimum temperature was 5.2°C and there was no precipitation.

Looking for information that's a little older? To determine how far back daily data is available for White Rock, click on the year dropdown menu to see what years of data are available. As you will see, White Rock's data goes back as far as 1929. On November 10th, 1929 the maximum temperature at the White Rock Campbell Scientific station in B.C. was 11.7°C, the minimum temperature was 2.2°C and there was no precipitation.

Another online resource that lists the monthly averages of daily temperature values across Canada is the Canadian Climate Normals or Averages. They contain averages and extremes for nearly 1500 locations across Canada for the periods of 1961 to 1990 and 1971 to 2000. In White Rock, B.C., for example, the daily average temperature for the month of November was 6.6°C for the period between 1971 to 2000.

Visit the National Climate Data and Information Archive for these and other historical data tools.

Related Sites:

• National Climate Data and Information Archive
• Weather Office - Five Day Weather Forecasts