Marine weather: land-based observations

In this section, learn how to better understand and use our land-based marine observation data, which is collected from our extensive network of monitoring equipment in coastal locations across Canada.

Cape Race

04:30 PM NST 9 March 2010

A sample current conditions page for a land based marine observation location
Wind (knots) WSW 16 Air temperature (°C) 0
Conditions N/A* Relative humidity (%) 100
Visibility (km) 8 Dew point temperature (°C) 0
Pressure and tendency (kPa) 100.0 ↓ Wind Chill -7
Sunrise 6:27 NST  Sunset 17:58 NST
* In the event a senor is malfunctioning or out of service for maintenance or the parameter is not measured, the field would be displayed as not available (N/A).

Observation Location (displayed in the mock up display as Cape Race)

Identified as the name of the observing location.

Time

The time of the observation is displayed in local time (Daylight Savings Time or Standard Time as required), hh:mm ddmmyyy, and typically updated shortly past the hour for hourly observations. In the event that a special or non-routine observation is available, this will be posted with an updated time.

Wind - Speed in Knots

The direction from which the wind is blowing from, using geographic cardinal or intercardinal points. A north wind is therefore a wind blowing from the geographic north. The speed is derived from a 2-minute mean or average prior to the time of the observation. In the event a gust is recorded, this is the maximum observed in a 10-minute period prior to the time of the observation.

Conditions

This is the representative condition reported at the observing site, based on the significance of the phenomena. It should be noted that some automated observing stations do not record current sky conditions, or their cloud detecting system only measures cloud below a certain height.

Visibility

Where available, this is the greatest distance, expressed in Kilometers, at which a black object of suitable dimensions could be seen and recognized. During hours of darkness, it could also be seen if under the same daylight conditions

Pressure and Tendency

The latest air pressure observed on the hour of the observation, in Kilopascals (kPa) with the trend of either rising or falling from the previous hour’s reading.

Air Temperature

The latest air temperature observed on the hour of the observation, in degrees Celsius to the nearest whole degree. 

Relative humidity

The percentage of humidity or relative humidity observed on the hour of the observation.

Dew point temperature

The latest dew point temperature observed on the hour of the observation, in degrees Celsius to the nearest whole degree. 

Wind chill Humidex

Wind chill is indicated in current conditions only when the temperature is 0°C or lower, with a wind speed of 2 km/h or more. In general, wind chill is mentioned in a forecast only if it is expected to be significant, that is to say if the wind chill is expected to be -25 or colder, with a forecast wind speed greater than 10 km/h.

The humidex is particularly significant when its value is greater than 30. We only display humidex values of 25 or higher for a location, which reports a dew point temperature above zero (0°C) and an air temperature of 20°C or more. Below this value, the humidex is too close to the air temperature to be considered significant.

Sunrise/ Sunset

Environment Canada is not an official source for this data, however as a courtesy, approximations for sunrise and sunset are available on the city forecast page nearest your location. Official times for sunrise and sunset can be found on the website of the National Research Council of Canada.

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