Weather Fax Transmissions from XSG Shanghai, China

Earlier last week, for the very first time I received weather fax transmission from XSG Shanghai in PR China. The received images were of charts mapping sea conditions from China’s east coast up past Japan and the Korean Peninsula. The signal and overall reception was very satisfactory imho.

Weatherfax is a unique and important broadcast service that transmits actual images over HF radio — anything from synoptic charts to wave maps — as audio tones decoded into graphics. These convey essential details about wave height, direction, and period. Mariners can use them to avoid dangerous sea states, optimize fuel use, and plan safer routes.

XSG is part of China’s national maritime network, broadcasting navigation warnings, weather updates, and safety information to a broad swath of the Northwest Pacific. These HF transmissions can reach far beyond coastal coverage and remain accessible to anyone with the right receiver and decoder.
For a radio hobbyist, part of the fascination lies in the process: the signal’s journey through the ionosphere, the subtle image imperfections caused by propagation, and the satisfaction of pulling a clean, usable chart out of the static. For professional mariners, these forecasts remain a trusted fallback when satellite communications fail.

From a science standpoint, each chart represents the end result of countless observations, model simulations, and careful processing — all rendered into a simple black-and-white format optimized for HF transmission.

I am quite excited to log these charts from the XSG station for the first time. As always receiving weather fax remains immensely fascinating to me.

Date: August 03, 2025
Location: Howrah, WB. India.

Station: XSG - Shanghai, PR China

Thank you so much for your kind attention. Comments, suggestions and correction (if required), will be very much appreciated.

- Soumya Bhattacharya