Appendix A — Network Quick Reference
This table covers the major observing networks accessible through the IEM. Network IDs follow IEM conventions (state-prefixed where applicable; the examples below use Pennsylvania). Archive depth reflects typical record start dates; individual stations vary. Use the station locator at mesonet.agron.iastate.edu/sites/locate.php to check the actual begin date and coverage flags for any specific station.
| Network ID (PA example) | Full Name | What It Measures | Archive Depth | Update Frequency | Key IEM URL |
|---|---|---|---|---|---|
| PA_ASOS | Pennsylvania ASOS | Temp, dew point, wind, visibility, ceiling, precipitation, pressure | ~1928 at major airports; ~1994–1996 at most stations | Hourly (plus specials); 1-minute archive at select sites | /ASOS/ |
| PACLIMATE | PA Long-Term Climate (COOP) | Daily max/min temp, precipitation, snowfall, snow depth | ~1888–present at longest-running stations | Once daily (observer-reported) | /COOP/ |
| PA_COCORAHS | PA CoCoRaHS | Daily precipitation, snowfall, hail | ~2007–present | Once daily (observer-reported) | /cocorahs/ |
| PA_DCP | PA Data Collection Platforms (HADS) | River stage, streamflow, soil temp/moisture, remote precip | Varies by station; some back to 1970s | Hourly; varies by station | /DCP/ |
| PA_RWIS | PA Roadway Weather Information Systems | Temp, wind, pavement temp, pavement condition, road cameras | ~2000–present | Every 20–60 minutes | /RWIS/ |
| PA_AWOS | Pennsylvania AWOS | Temp, wind, altimeter; precipitation and sky at AWOS-3P sites | ~1993–present | Varies by tier; typically hourly | /AWOS/ |
| IACLIMATE (Iowa example) | Iowa COOP Long-Term | Same as COOP; Iowa-specific archive | ~1873–present | Once daily | /COOP/ |
| ISUSM | ISU Soil Moisture Network | Soil temp and moisture at multiple depths, air temp, solar radiation, ET | ~2012–present | Hourly | /agclimate/ |
| SCAN | USDA NRCS Soil Climate Analysis Network | Soil temp and moisture at multiple depths, air temp, wind, solar radiation, precipitation | ~2000–present at most sites | Hourly | /scan/ |
| USCRN | U.S. Climate Reference Network | Triple-redundant temp, precipitation, solar radiation, wind, soil temp/moisture | ~2002–present | Hourly | /uscrn/ |
| NLAE | NLAE Flux Tower Network | Eddy covariance flux measurements (energy, CO₂, water vapor), micromet | Varies by tower | Sub-hourly | /nstl_flux/ |
| SCHOOLNET | TV Station Schoolnet / WeatherNet | Temp, dew point, wind, precipitation; varies by station | ~2000–present at oldest stations | Typically hourly | /other/ |
| HADS (national) | Hydrometeorological Automated Data System | River stage (HP), streamflow (QR), precip (PC), soil temp (TS); SHEF-coded | Varies | Hourly to 6-hourly | /DCP/ |
| IEMRE (gridded) | IEM Reanalysis | Gridded temp, precipitation, solar radiation — ¼° grid, CONUS | 1893–present | Daily update | /iemre/ |
Notes on Network Coverage Flags
When you pull up any ASOS or AWOS station page, the attribute flags below tell you what data is actually available beyond the basic hourly observation. These flags appear in the station metadata and matter when you are deciding which station to anchor an analysis on.
| Flag | Meaning |
|---|---|
HAS1MIN=1 |
1-minute ASOS archive available (download at /request/asos/1min.phtml) |
HAS_PHOUR=1 |
Hourly precipitation bucket data available |
HASTAF=1 |
Terminal Aerodrome Forecasts issued for this station |
IS_AWOS=1 |
Station is AWOS, not ASOS — check tier for capability |
GHCNH_ID |
Corresponding GHCN-Hourly identifier (NCEI cross-reference) |
FLOOR |
Earliest date IEM considers reliable for this station — may differ from archive begin |
SHEF_6HR_SRC |
DCP gauge used to supplement 6-hour precipitation totals |
Network Comparison at a Glance
| Network | Historical Depth | Spatial Density | Precip Quality | Best Use Case |
|---|---|---|---|---|
| ASOS | High (80+ years at major airports) | Low–Medium (airports only) | Good; known snowfall undercount | Hourly climatology, event timing, standard obs |
| COOP | Very High (130+ years at oldest sites) | Medium | Good; observer-consistent | Long-term climate trends, daily extremes, normals |
| CoCoRaHS | Low (~2007) | Very High (volunteer density) | Good; standardized gauge | Precipitation spatial variability, storm totals |
| DCP/HADS | Medium (1970s–present) | Low (river/remote sites) | Variable | River stage, hydrology, remote area obs |
| RWIS | Medium (~2000) | Low–Medium (highway sites) | Poor | Pavement conditions, winter event analysis |
| USCRN | Low (~2002) | Very Low (~130 national sites) | Excellent | Climate trend detection, reference quality obs |
| SCAN | Low (~2000) | Very Low (research sites) | High | Soil temperature and moisture, agricultural research |
| IEMRE | Very High (1893; gridded) | Complete (¼° grid) | Derived | Gap-filling, regional background fields |
Finding Network Station Lists
Every IEM network has a station table listing all member stations with coordinates, archive dates, and attributes. The network tables are at mesonet.agron.iastate.edu/sites/networks.php — select your state and network from the dropdown. The full table can be exported as CSV or shapefile for use in GIS software or analysis scripts.
For single-station lookup by name, coordinates, or state, use the station locator at mesonet.agron.iastate.edu/sites/locate.php.