Hourly Mercedes Weather Forecast; Abbreviated Mercedes Weather Forecast; 6 Day/Night Mercedes Weather Forecast; 7 Day Mercedes Weather Forecast; 14 Day Mercedes Weather Forecast; 78570 Zip Code Weather Forecast; Weather Radar. Radar; Radar Loop; Warnings/Advisories; NowCast Regional Weather; Local Climate Averages; Pinpoint. Mercedes, TX Monthly Weather Forecast - weather.com Monthly Weather - Mercedes, TX As of 11:12 am CDT Sep View Nov Sun mon tue wed thu fri sat 1 94° 76° 2 96° 76° 3 101° 77° 4 101° 80° 5.