A Virtual Climate station is the result of threading together climate data from proximate current and historical stations to construct a long term threaded data set. For the purpose of identifying and tabulating daily extremes of record for temperature, precipitation and snowfall, the Meteorological Service of Canada has threaded or put together data from closely related stations to compile a long time series of data for about 750 locations in Canada to monitor for record-breaking weather. The length of the time series of virtual stations is often greater than 100 years. A Virtual Climate station is always named for an “Area” rather than a point, e.g. Winnipeg Area, to indicate that the data are drawn from that area (within a 20km radius from the urban center) rather than a single precise location.

Le SMC (Service météorologique du Canada) recueille des données atmosphériques depuis 1850 et continue de le faire. Pour collecter les données atmosphériques, on mesure les vitesses des vents, la pression atmosphérique, la vitesse de déplacement du système et l'information sur les coordonnées de l'emplacement des mesures, de même que la date et l'heure à toutes les six heures. Ces données sont classées par catégorie de perturbation et chaque perturbation se voit attribuer un nom et une classification d'après la vitesse maximale de ses vents, à toutes les lectures effectuées aux six heures. Ce service fournit toutes les données de mesure des perturbations disponibles.

Anomalous weather resulting in Temperature and Precipitation extremes occurs almost every day somewhere in Canada. For the purpose of identifying and tabulating daily extremes of record for temperature, precipitation and snowfall, the Meteorological Service of Canada has threaded or put together data from closely related stations to compile a long time series of data for about 750 locations in Canada to monitor for record-breaking weather. Virtual Climate stations correspond with the city pages of weather.gc.ca. This data provides the daily extremes of record for Precipitation for each day of the year. Daily elements include: Greatest Precipitation.

The Air Quality Health Index (AQHI) is a scale designed to help quantify the quality of the air in a certain region on a scale from 1 to 10. When the amount of air pollution is very high, the number is reported as 10+. It also includes a category that describes the health risk associated with the index reading (e.g. Low, Moderate, High, or Very High Health Risk). The AQHI is calculated based on the relative risks of a combination of common air pollutants that are known to harm human health, including ground-level ozone, particulate matter, and nitrogen dioxide. The AQHI formulation captures only the short term or acute health risk (exposure of hour or days at a maximum). The formulation of the AQHI may change over time to reflect new understanding associated with air pollution health effects. The AQHI is calculated from data observed in real time, without being verified (quality control).

Climate observations are derived from two sources of data. The first are Daily Climate Stations producing one or two observations per day of temperature, precipitation. The second are hourly stations that typically produce more weather elements e.g. wind or snow on ground.

The Operational Hydrodynamic Prediction System (OHPS) is a 2D hydrodynamic prediction system for the St. Lawrence River and fluvial estuary. It helps to better understand flows impacting the St. Lawrence ecosystem and serves as a decision-making tool for the integrated management of the St-Lawrence. Three components are integrated in OHPS system. The first one "steadysol" conducts daily steady-state flow analyses, 4 times per day at 00Z, 06Z, 12Z and 18Z, respectively, over a simulation domain extending from Montreal to Trois-Rivières. The second and third components, i.e. "analysis" and "forecast", provide continuous analyses and 48-hrs forecasts, respectively, for unsteady flows over an extended St. Lawrence domain of which the upstream boundaries locate in Carillon and Beauharnois while the downstream tidal boundary is near Saint-Joseph-de-la-Rive, respectively, 4 times a day at 00Z, 06Z, 12Z and 18Z. The system provides high-resolution outcomes for various parameters such as water levels, depth-averaged velocities and derived attributes, over the simulated domains. The products are available in the NetCDF format, which provides datasets. The published datasets of "steadysol" is over an irregular triangulated mesh, while the datasets of "analysis" and "forecast" are over a Polar Stereographic grid.

Anomalous weather resulting in Temperature and Precipitation extremes occurs almost every day somewhere in Canada. For the purpose of identifying and tabulating daily extremes of record for temperature, precipitation and snowfall, the Meteorological Service of Canada has threaded or put together data from closely related stations to compile a long time series of data for about 750 locations in Canada to monitor for record-breaking weather. Virtual Climate stations correspond with the city pages of weather.gc.ca. This data provides the daily extremes of record for Temperature for each day of the year. Daily elements include: High Maximum, Low Maximum, High Minimum, Low Minimum.

Anomalous weather resulting in Temperature and Precipitation extremes occurs almost every day somewhere in Canada. For the purpose of identifying and tabulating daily extremes of record for temperature, precipitation and snowfall, the Meteorological Service of Canada has threaded or put together data from closely related stations to compile a long time series of data for about 750 locations in Canada to monitor for record-breaking weather. Virtual Climate stations correspond with the city pages of weather.gc.ca. This data provides the daily extremes of record for Snowfall for each day of the year. Daily elements include: Greatest Snowfall.

The Regional Deterministic Precipitation Analysis (RDPA) produces a best estimate of the amount of precipitation that occurred over recent past periods of 6 or 24 hours. The estimate integrates data from in situ precipitation gauge measurements, weather radar, satellite imagery and numerical weather prediction models. Geographic coverage is North America (Canada, United States and Mexico). Data is available at horizontal resolution of 10 km. Data is only available for the surface level. Analysis data is made available four times a day for 6h intervals and twice a day for the 24h interval. A preliminary estimate is available approximately 1h after the end of the accumulation period, and revised 7h after in order to assimilate gauge data arriving later.

A station is a site on a river or lake where water quantity (water level and flow) are collected and recorded.