Welcome to WxCoder – the official web-based entry system for the National Weather Service (NWS) Cooperative Observer Program (COOP). WxCoder provides the means for entry of daily weather measurements by COOP volunteers. WxCoder also logs subhourly measurements from data loggers and sensor suites as they become part of the network.

COOP consists of thousands of dedicated volunteers who take observations at farms, urban and suburban areas, National Parks, seashores, and mountaintops. The input data are truly representative of where people live, work, and play. Since 1890, COOP has fulfilled key mission elements:

• To provide observational meteorological data, usually consisting of daily maximum and minimum temperatures, snowfall, and 24-hour precipitation totals, required to define the climate of the United States and to help measure long-term meteorological changes
• To provide observational meteorological data in near real-time to support forecast, warning and other public service programs of the NWS.

WxCoder is sponsored by the National Oceanic and Atmospheric Administration (NOAA) through the NWS and by the National Centers for Environmental Information (NCEI).

The collection of COOP information is authorized under OMB Control Number 0648-0828 (exp. 9/30/2027) and as described in the Citizen Science & Crowdsourcing Information Collection.

If you are a COOP observer, log in to report your daily observations.