Intelligent Roadway Information System

Road Weather Information Systems

Road Weather Information Systems, or RWIS can sense data such as precipitation rate, road surface temperature, wind speed, etc. The NTCIP and Org-815 protocols can collect RWIS data.

API Resources 🕵️
  • iris/rwis (see below)
  • iris/api/weather_sensor (primary)
  • iris/api/weather_sensor/{name}
Access Primary Secondary
👁️ View name, location geo_loc, settings, sample, sample_time
💡 Manage site_id, alt_id, notes
🔧 Configure controller pin

Public JSON Data

The iris/rwis endpoint produces a JSON document containing an array of all weather sensor objects.

Key Value
name Weather sensor name
location Location description
lat Latitude of sensor
lon Longitude of sensor
settings Settings object
sample Observation sample object
sample_time Time stamp of observation


This object contains sensor settings and configuration.

Key Value
reference_elevation Reference elevation above mean sea level (meters)
pressure_sensor_height Height relative to reference_elevation (meters)
wind_sensor Array of wind sensor settings objects
↳height Height relative to reference_elevation (meters)
temperature_sensor Array of temperature sensor settings objects
↳height Height relative to reference_elevation (meters)
pavement_sensor Array of pavement sensor settings objects
↳location Sensor location description
↳pavement_type Pavement type description
↳height Pavement height relative to reference_elevation (meters)
↳exposure Rough estimate of solar energy (percent)
↳sensor_type Sensor type description
sub_surface_sensor Array of sub-surface settings objects
↳location Sensor location description
↳sub_surface_type Sub-surface type description
↳depth Depth below pavement surface (meters)


This object contains all collected observation data from the most recent polling period. The wind_sensor, temperature_sensor, pavement_sensor and sub_surface_sensor arrays match the order from the settings object.

Key Value
atmospheric_pressure Atmospheric pressure (pascals)
visibility Visibility (meters)
visibility_situation Visibility situation description
wind_sensor Array of wind sensor observations
↳avg_speed Two minute average wind speed (m/s)
↳avg_direction Two minute average wind direction †
↳spot_speed Spot wind speed (m/s)
↳spot_direction Spot wind direction †
↳gust_speed Ten minute maximum wind gust speed (m/s)
↳gust_direction Ten minute maximum wind gust direction †
↳situation Wind situation description
temperature_sensor Array of temperature sensor observations
↳air_temp Instantaneous air temperature (℃)
wet_bulb_temp Instantaneous wet-bulb temperature (℃)
dew_point_temp Instantaneous dew point temperature (℃)
max_air_temp Maximum 24 hour air temperature (℃)
min_air_temp Minimum 24 hour air temperature (℃)
relative_humidity Relative humidity (percent)
precip_rate Precipitation rate (mm/hr)
precip_1_hour One hour accumulated precipitation (mm)
precip_3_hours Three hour accumulated precipitation (mm)
precip_6_hours Six hour accumulated precipitation (mm)
precip_12_hours Twelve hour accumulated precipitation (mm)
precip_24_hours Twenty-four hour accumulated precipitation (mm)
precip_situation Precipitation situation description
pavement_sensor Array of pavement sensor observations
↳surface_status Surface status description
↳surface_temp Surface temperature (℃)
↳pavement_temp Pavement temperature (℃)
↳sensor_error Sensor error description
↳ice_or_water_depth Surface ice or water depth (meters)
↳salinity Salinity (ppm by weight)
↳freeze_point Surface freeze point (℃)
↳black_ice_signal Black ice signal description
↳friction Coefficient of friction (percent)
sub_surface_sensor Array of sub-surface observations
↳temp Sub-surface temperature (℃)
↳moisture Sub-surface moisture saturation (percent)
↳sensor_error Sensor error description
total_sun Sun during previous day (minutes; 0-1440)
cloud_situation Cloud situation description
solar_radiation Solar radiation (joules / m²) deprecated
instantaneous_terrestrial_radiation Terrestrial radiation (watts / m²)
instantaneous_solar_radiation Solar radiation (watts / m²)
total_radiation Total from collection period (watts / m²)
total_radiation_period Total radiation period (seconds)

† Wind direction in degrees clockwise from due north.