Here's an example of a METAR and how it works. You should note that user friendly decoded METARs are very common and available both online and in mobile apps.
KORD 192151Z 29012G31KT 10SM SCT180 BKN210 BKN250 14/M03 A2960 RMK AO2 PK WND 29031/2143 SLP026 T01391028 $
The first word is the ICAO airport code KORD. ICAO codes are unique identifiers for airports which makes them useful for refrence especially in navigation equipment and aviation software.
192151Z is the time the conditions were recorded. This METAR is from the 19th at 21:51Z (Zulu). Zulu time is the same as UTC and is used in most aviation reports. METARs are always transmitted shortly after they are recorded so the month and year are not shown in the timestamp. This METAR is from March 19th 2024.
29012G31KT Wind direction is 290° as referenced to true north. The wind is 12 knots with gusts up to 31 knots.
10SM Visibility is 10 statute miles or better. 10 is often used on a clear day to mean "at least 10 miles"
Ranges from Sky clear (SKC) to Overcast (OVC) - SCT180: A layer of clouds are scattered starting 18,000ft above the airport. Scattered means 3/8 to 4/8 of the sky is covered. - BKN210: Clouds are Broken at 21,000ft above the airport. Broken means 5/8ths to 7/8ths of the sky is covered. - BKN250: Another layer of clouds is Broken at 25,000ft above ground level (AGL).
14/M03 means the temperature is 14° Celcius with a dew point of -3° Celcius. When the dewpoint is within about 3 degrees of the temperature you can expect clouds to form if it gets any cooler. This dewpoint spread is important to watch out for when flying VFR.
A2960 means 29.6 inches of mercury. This is a pressure setting used to adjust the altimeter in an aircraft so that it indicates the height of the aircraft above a known reference surface. In the US, the reference surface is Mean Sea Level (MSL).
RMK indicates the start of the remarks section. - A02: This is an automated station with a precipitation sensor, it should have information on the type of precipitation, e.g. snow, hail, rain etc if applicable. - PK WND 29031/2143: Peak wind. The direction of the peak wind is 290 degrees (from the west), and the speed is 31 knots. The peak wind occurred at 21:43 UTC. - SLP026: Sea Level Pressure. The sea level pressure is 1002.6 millibars (mb). To get the pressure value, add 1000 to the reported number (1000 + 2.6 = 1002.6). - T01391028: Expanded temperature and dewpoint. 0139 means 13.9° C, 1028 means -2.8° C. The leading 0 and 1 indicate postive and negative values respectively. - $: Quality Control flag. The sensor requires maintenance.
While this was just one example of a METAR, I hope you'll find this breakdown useful. Fortunately in most cases you can get the METAR in a more user friendly format.
Check out this other example which also gives some good info on decoding TAFs, ASOS and AWOS: https://met.nps.edu/~bcreasey/mr3222/files/helpful/DecodeMETAR-TAF.html
You can also access the whole metar decode key from here:https://atisrelay.com/blog/metar-taf-decode-key