• Red (upper-left): temperature (°C)
• Green (lower-left): dewpoint (°C)
• Blue (upper-right): abbreviated mean sea-level pressure in hPa (=mb). To get the pressure value, just put a 10 or a 9 in front of the displayed value and divide by 10: only one of these choices will give a realistic value.
• Magenta (center-left): weather symbol
• Blue (center): cloud cover in octa
• Blue (barb): wind speed in knots and wind direction
• Orange: pressure tendency in the last 3 hours in tenth of hPa
• Purple (left-upper-left): Wind gust in knots
• Upper-center and lower-center (few stations): cloud type symbols

• Black lines: pressure (hPa=mb) lines each 4 hPa analyzed with Barnes algorithm from surface observations and first guess model data (digital filter)
• Red dashed-lines: geopotential height at 500 hPa each 6 dam analyzed with Barnes algorithm from upper-air observations and first guess model data

Decoding time stamp example:

sfc/210613/2300 upa/210613/12

sfc = Surface
210613/2300: year=2021; month=06 (June); day=13; 2300=23:00 UTC

upa = Upper-air
210613/12: year=2021; month=06 (June); day=13; 12=12 UTC