1. RWIS Homepage
2. Download

RWIS Atmospheric / Surface Data Download

The IEM archives RWIS information for the network in Iowa based on a direct feed from the DOT. We also archive other states based on an archive provided by the MADIS project. Data for Iowa dates back to 1995, whereas we only have data for other states back to 2009. The archive has some holes in it around the year 2000 and 2001, but it mostly in tack outside of those dates.

Backend documentation exists for those wishing to script against this service.

2. Select Start/End Time:

Times are in timezone you select in step 5 below.

	Year	Month	Day	Hour
Start:	199519961997199819992000200120022003200420052006200720082009201020112012201320142015201620172018201920202021202220232024	JanFebMarAprMayJunJulAugSepOctNovDec	12345678910111213141516171819202122232425262728293031	12 AM01 AM02 AM03 AM04 AM05 AM06 AM07 AM08 AM09 AM10 AM11 AM12 PM01 PM02 PM03 PM04 PM05 PM06 PM07 PM08 PM09 PM10 PM11 PM
End:	199519961997199819992000200120022003200420052006200720082009201020112012201320142015201620172018201920202021202220232024	JanFebMarAprMayJunJulAugSepOctNovDec	12345678910111213141516171819202122232425262728293031	12 AM01 AM02 AM03 AM04 AM05 AM06 AM07 AM08 AM09 AM10 AM11 AM12 PM01 PM02 PM03 PM04 PM05 PM06 PM07 PM08 PM09 PM10 PM11 PM

3. Select Variables:

The label value within parenthesis is the output column name.

Air Temperature [F] (tmpf) Dew Point Temperature [F] (dwpf) Wind Speed [knots] (sknt) Wind Direction [degree N] (drct) Wind Gust [knots] (gust) Pavement Sensor0 Temperature [F] (tfs0) Pavement Sensor0 Condition (tfs0_text) Pavement Sensor1 Temperature [F] (tfs1) Pavement Sensor1 Condition (tfs1_text) Pavement Sensor2 Temperature [F] (tfs2) Pavement Sensor2 Condition (tfs2_text) Pavement Sensor3 Temperature [F] (tfs3) Pavement Sensor3 Condition (tfs3_text) Subsurface Temperature [F] (subf)
See below for discussion on "Pavement Sensor* Condition"

4. How to view?

Download as Delimited Text File Download as Excel View as HTML webpage

5. Timezone of Timestamps

This controls the timezone used for presenting the timestamps in the downloaded file.
Coordinated Universal Time (UTC) America/New_York (EST/EDT) America/Chicago (CST/CDT) America/Denver (MST/MDT) America/Los_Angeles (PST/PDT) America/Anchorage (AKST/AKDT)

6. Data Delimitation:

How shall the output values be seperated?
Comma Space Tab

7. Include Lat / Lons?

No Yes

8. Submit Form:

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Pavement Sensor Condition Explaination

The following applies to most of the Iowa RWIS sensors and is passed along by the Iowa RWIS Coordinator.

The data is taken from the Vaisala FP2000. These readings can be lumped into four general categories: wet, dry, snow/ice, error. The sensor gives quite a few more, especially in the snow/ice realm but functionally it is difficult to distinguish clear differences between them.

From the glossary:

Status	Description
Snow/Ice Warning	Continuous film of ice and water mixture at or below freezing (32°F / 0°C) with insufficient chemical to keep the mixture from freezing. This status can only be reported at Vaisala ESP and SP sites when precipitation occurs.
Ice Warning	Continuous film of ice and water mixture at or below freezing (32°F / 0°C) with insufficient chemical to keep the mixture from freezing. This status can only be reported at NTCIP sites.
Snow Warning	This status can be reported at NTCIP sites, but will not be reported by Vaisala NTCIP sites.
Wet Below Freezing	Moisture on pavement sensor with a surface temperature below freezing (32°F / 0°C). This status will only be reported at Vaisala SCAN Detector sites.
Ice Watch	Thin or spotty film of moisture at or below freezing (32°F / 0°C). This status can only be reported at NTCIP sites when precipitation is not occurring.
Snow/IceWatch	Thin or spotty film of moisture at or below freezing (32°F / 0°C). This status can only be reported at Vaisala ESP and SP sites when precipitation is not occurring.
Snow Watch	This status can be reported at NTCIP sites, but is not detected at Vaisala NTCIP sites.
Frost	Moisture on pavement at or below freezing (32°F / 0°C) with a pavement temperature at or below the dew point temperature. This status can only be reported by Vaisala ESP, SP, and NTCIP sites when precipitation is not occurring.
Chemical Wet	Continuous film of water and ice mixture at or below freezing (32°F or 0°C) with enough chemical to keep the mixture from freezing. This status can only be reported by Vaisala ESP, SP, and NTCIP sites when precipitation occurs.
Wet	Continuous film of moisture on the pavement sensor with a surface temperature above freezing (32°F or 0°C). This status can be reported by Vaisala ESP, SP, SCAN Detector, and NTCIP sites when precipitation has occurred.
Damp	Thin or spotty film of moisture above freezing (32°F or 0°C). This status can only be reported by Vaisala ESP, and SP sites when precipitation is not occurring.
Trace Moisture	Thin or spotty film of moisture above freezing (32°F or 0°C). Surface moisture occurred without precipitation being detected. This status will only be reported at NTCIP sites when precipitation is not occurring.
Absorption at Dew Point, Absorption, & Dew	These statuses can be reported at NTCIP sites, but are not currently detected at Vaisala NTCIP sites.
Dry	Absence of moisture on the surface sensor. This status can be reported by Vaisala ESP, SP, SCAN Dectector, and NTCIP sites.
Other	Other is the standard NTCIP ESS surface condition code to handle conditions not explicitly included in this table. This status will only be reported NTCIP by sensors installed at NTCIP ESS sites.
No Report	The surface sensor is not operating properly and requires maintenance. This status will only be reported by Vaisala ESP and SP sites.
Error	The surface sensor is not operating properly and requires maintenance. This status will only be reported by NTCIP sites.