Data Explanation
Data History Help
Export Data Help

Data Explanation

RWIS data is updated regularly and usually takes about 40 minutes from the time of the sensor reading to displaying the data on the web site.

ATMOSPHERIC MEASUREMENTS

Date / Time (PST) – This column shows the date and time of the latest RWIS data collected.
Data may appear in a shade of red if the age of latest reading (L)is:

  • 4 hrs < L < 12 hrs, then date/time is displayed in normal red
  • 12 hrs <= L < 24 hrs, then date/time is displayed in italic red
  • 24 hrs <= L, then date/time is displayed in bold red

Wind Speed (MPH) – This data is collected from an anemometer. Wind speed is calculated by using an average of many instantaneous readings over a period of time.

Wind Direction – This data is collected from a wind vane and is the average of many instantaneous readings over a period of time. Compass abbreviations show the direction wind is coming from. The arrows on the gauge display show the direction of wind movement.

Gust Speed (MPH) – Gust speed uses the same equipment as wind speed but is calculated on the average of several highest readings obtained over a period of time.

Gust Direction – This uses the same equipment as wind direction but is calculated on the average of several highest readings obtained over a period of time. Compass abbreviations show the direction wind is coming from. The arrows on the gauge display show the direction of wind movement.

Air Temperature (ºF) – Air temperature is sampled many times per minute and the reading displayed is the most recent value sampled.

Relative Humidity (%) - In simple terms, relative humidity is a measure of the amount of water in the air compared with the maximum amount of water the air could hold at a given temperature.

Dew Point (ºF) – In simple terms, dew point is the temperature at which the air becomes saturated. When air temperature drops to near the dew point temperature, moisture can begin to accumulate on road surfaces. The dew point is calculated from air temperature and relative humidity.

Rain (yes or no) – A heated sensor plate detects and quickly evaporates occasional rain drops. As additional rain drops hit the plate, the sensor can estimate rain intensity.

Rain Rate (in/hr) – See the Rain explanation above.


Data History Help

You can view historical RWIS data from the "Station History Listing".

1. Enter a "from" date and "to" date (mm/dd/yyyy). The oldest available data begins on February 1, 2009 and the range of data cannot exceed 31 consecutive days.

2. After the "from" and "to" dates have been entered, select "Get Date Range of History" and weather data for the range selected will be displayed. This may take some time depending on the amount of data you have requested and the speed of your internet connection.



Export Data Help

You can download RWIS data to your computer by displaying the history you want and then clicking on the "Export Data" button.


Data is subject to change. For weather forecasts, use the following links:
Disclaimer:
NDOT provides the foregoing information as a public service. This information is published automatically and cannot be guaranteed as to accuracy or timeliness. This information depends on a number of items, including Internet availability, communications networks, and computer equipment which are beyond the control of the NDOT and difficult to predict.

Listing of roadway snow and ice conditions is not a guarantee that NDOT has plowed or sanded all of these locations for travelers. Plowing and sanding is generally done to different roads on a basic priority system but that the actual determination of the amount and timing of sanding and plowing of any particular section of highway is up to the judgment of local road maintenance officials based on their experience and local conditions at particular times.

Weather and road conditions change rapidly, and drivers are in the best position to perceive such conditions and adjust their driving accordingly. Those relying on the foregoing information do so at their own risk, and neither the State of Nevada, the NDOT nor any of their employees or agents shall be liable for either the accuracy of this information nor any actions taken in reliance thereon.