Weather Data Sources
ClimaCiudad retrieves and processes meteorological information for cities in the United States and Puerto Rico, using official sources from the U.S. National Oceanic and Atmospheric Administration (NOAA).
National Weather Service (NWS)
We use observations and forecasts from the National Weather Service to present current conditions, hourly predictions and daily weather forecasts.
Observations come from weather stations and may differ from conditions at another location within the same city.
Official source: weather.gov.
Global Forecast System (GFS)
To extend the forecast period, we use information from NOAA/NCEP's Global Forecast System, primarily covering forecast days 8 through 14.
Daily high and low temperatures in the extended forecast are calculated from available model data. Uncertainty generally increases further into the forecast period.
Official source: NOAA/NCEP — GFS.
Weather data updates
Our system schedules current-condition updates every hour, NWS forecast updates every six hours and GFS updates daily.
These are scheduled frequencies. Actual updates may be delayed or interrupted.
Weather pages display the available update time. Forecast hours are presented using each city's local time zone.
Unavailable information
Not all data sources provide the same variables. For example, our current processing of GFS data does not include daily precipitation probability percentages.
When a variable is unavailable, its absence must not be interpreted as a zero value.
Forecast limitations
Weather forecasts are estimates and may change. Some cities may have fewer than 14 days of forecast information available at a given time.
ClimaCiudad presents and processes weather data. We are not an official warning or emergency agency.
Weather alerts and safety
During hazardous weather, consult official alerts and guidance from the National Weather Service and relevant local authorities.