Introduction to clearweather.ca

The basics

Weather station observations

These pages provide access to 2300 weather stations run by Canadian federal, provincial and regional governments and Nav Canada. All stations report at least hourly, generally within a few minutes of the observations but some can take an hour or two to appear.

Precipitation

Almost all stations report precipitation of one sort or another, usually rain or 'precipitation' (snow or rain) by weight and many report snow depth. Precipitation measurement by weight requires other parameters, such as temperature, to distinguish rain from snow.

Weather radar

Stations provide accurate observations of rain and precipitation. Radar provides good coverage, filling in the gaps between stations. 6 minute (10 minutes before Aug 2024) real-time radar updates complement a national network of about 350 stations that are available here every 10 minutes.

Weather satellite

Use the satellite imagery in the standard view to see small features such as low cloud, fog, local smoke, snow squalls or showery weather. Adjust the satellite 'visibility' to 100% to better see the features. Use the 'day only view' in daylight hours.

Public forecasts

EC public forecast regions shown on maps (View menu) can be selected to show the latest and recent forecasts out to 7 days.

Weather models

Select a station for links to weather model graphs of forecast wind, temperature, rain and snow provided by spotwx.com configured for the station location.

Fast

Enjoy uncomplicated and fast access to the observations, forecasts and weather models.

Put it all together

Combine current conditions and public forecasts supplemented by weather models to make your own DIY forecast that, with a bit of practice, can be done in a minute or two.

Official public forecasts are general descriptions of the expected weather over a region. A forecast of "40% chance of showers today" doesn't tell you much about the next hour or two but checking local radar and observations might.

Learn

The weather is a big part of the natural world and it's different every day. Get to know your local hills and mountains, valleys, lakes and rivers by seeing how the weather affects them and is affected by them. For this to remain interesting the process has to be snappy. This website is an attempt to provide enough data in an efficient way to make that work.

And it's Canada, where weather gets major air time. Next time there's a big weather event you can check it out yourself even if it's at the other end of the country.

The tools

This site can work fairly well on small screens but it's easier to use a tablet or larger screen for the first visit or two. If using a small screen, try the standard view in landscape mode and zoom out to tap the map edge for panning. You'll have to scroll up and down to see station observations or other radar scans.
The first three items in the View menu are different tools all designed for real time use so the latest observations are always included. There is also an option to add a date/time entry form for past data back to June 2021.

1. Standard view for Canada-wide navigation

• This is the one to use in most cases.
• Radar and satellite animations are shown on 480x480 km maps. Try setting the satellite visibility to 100%.
• Navigate using the Move menu or click near a map edge or corner.
• Select a few station dots on the map to see the observations. Use the help links below to decipher column headings.
• Choose a field (eg. temperature) under "Observations" and then click on several stations to form a table for several locations.
• Select "EC public forecast regions" in the View menu and choose a region on the map for its current forecasts.

2. Centre map on nearest station

• This one has no radar or satellite but has +/- zoom buttons to better separate closely packed stations such as in southern Ontario.

3. Centre map on nearest radar

• This is a deeper dive into weather radar. Choose from the Scans menu for more radar scan types.
• Select 'current active weather in Canada' on the Move menu for the most active (stormy) weather on radar at the moment.

4. Displaying observations for periods longer than 3 days.

• The radar and satellite animations are limited to 3 days and this will limit observations as well.
• Remove the animations by deselecting them under the Radar and Satellite pull-down menus in the Standard view or use the stations centered view (#2) which offers no radar or satellite.

Bits and pieces

Map stations menu: station types and what they do

• MSC auto: year round wind, temperature, humidity, rain, snow and precipitation
• Forestry: summer rain, wind, humidity for forestry and agriculture
• Highways: snow anywhere and high elevation stations in BC/YT for avalanches forecasting
• Marine: manned lighthouses, buoys, coastal MSC autos with exposure to marine winds
• Airports: manned and auto, winds, temperature, pressure, visibility and weather (Nav Canada, DND, manned and auto)

Cross-Canada coverage with 'MSC auto 10 minutes' and 'MSC auto hourly'

These stations plus Nav Canada airport observations are the bread and butter of public weather forecasters in Canada. You'll see two to 12 hours or more of all relevant parameters when you select a station. This makes it easier to interpret precipitation readings and whether the precipitation is snow, rain, freezing rain, etc. You're also less likely to miss the surprises that inevitably come along.

Station location

A station's location, whether near hills or mountains, a large lake or the ocean, will affect its weather. Look for the "stn info" link in the observations box. The larger maps locate the station relative to large features such as mountains or a river valley and the 1x1 km aerial photo can show whether it might be protected from wind by nearby trees. The google maps link will open a close-up view and the pinned station location.

Data start dates

• Earliest station observations (many start later): June 2021
• Radar 10 minute national composite data: April 2022
• Radar 6 minute national composite data replaces 10 minute data: Aug 2024
• Individual radar 6 minute scans: June 2023
• Alternative DPQPE radar scan: 01 January 2023.
• Satellite data: August 2024

Help pages

You'll see links to these help pages.
• Quick guide/View menu.
• Introduction.
• Station observations column headings.
• Precipitation terms and what to watch.
• Radar information and loops controls.
• Weather model graphics by Spotwx.com.
• Radar scans.
• Weather station types.
• DIY forecasting.

Terms of use and data sources

Data on this site (clearweather.ca) are provided as a public service, are not owned by the site and are presented "as is" with no guarantees of any kind. Please read the Terms of use. All sources of data on this site are free and open to all.

Watch out!

Always check the date/time on the observations and that the time zone is what you expect. Stations occasionally go missing for short or long periods of time.

If a sensor fails it often reports a zero, particularly for wind speed. If something doesn't look right then maybe it isn't.