People often see delays caused by weather, and they wonder how things are so exact in aviation. 

I'm going to give you a brief demonstration of what a pilot and operations would see with regards to conditions at an airfield. 

But first... think to yourself what does a pilot need to know about the weather? 

A pilot will get the following from an airfield. 

METAR: EGNS 301120Z 33020G32KT 290V010 9999 FEW028 14/06 Q1021 NOSIG

That's right, it looks like an indecipherable code. But it's actually a very simple standardised way of showing what the actual conditions are at an airport all over the world. A lot of information is contained within the line, and a typical METAR contains data for the temperature, dew point, wind speed and direction, precipitation, cloud cover and heights, visibility, and barometric pressure. Pretty much anything a pilot could need. I'll explain below.

Each section is actually describing a different section of the airfield

Example 1: 

EGNS 301120Z 33020G32KT 290V010 9999 -RA FEW028 14/06 Q1021 NOSIG

EGNS: This is the airfield the report is from. Each airport has a 4 letter code designating it. For example, Manchester is EGCC, Isle of Man is EGNS, and say JFK in the US is KJFK. 

301120Z: This tells you the date and time it's valid from. The 30 at the start means its from the 30th of the month. The 1120 means that it was taken at 1120. The Z stands for Zulu time, which is used to have the same time all over the world. 

33020G32KT: This tells you Wind Speed and Direction. The 330 tells you that the wind is blowing from 330 degrees (so from the North west). The 20G32KT means that the wind is blowing 20 knots, but there are Gusts of up to 32 knots. 

290V010: This tells you that the Wind direction is changable, and that the wind is mainly coming from 330 in the above, but it's varying between 290 and 010 degrees. 

9999: This tells you the visibility at the airport is more than 9999 meters. So it's a really good day for visibility.

-RA: This is the current precipitation, such as rain, snow, fog or hail. The minus means light (a plus means heavy), and the RA means Rain. There are other codes too, but you can find them yourselves.

FEW028: This tells you about the cloud at the airport. The sky is split into roughly 8 oktas. FEW028 means that at 2800 feet, there are FEW clouds, which is about 3 or 4 oktas out of 8 in the sky filled with clouds. 

14/06: This is the temperate and the dew point at the airport. 14 Degrees Celsuis, and 06 Degrees for the dew point.

Q1021: This is the atmospheric pressure above mean sea level which is used to set the aircraft altimeter. Different atmospheric pressure means that your altimeter will read differently, roughly 27 ft for every 1 millibar difference. Q1021 means that the atmospheric pressure above mean sea level is 1021 millibars / hectopascals. 

NOSIG: This simply means there has been no significant change since the last report

And that's it. Basically, the above is telling us that it's a bit windy, but a pretty good day. 

---

We'll do one a little bit harder now. 

Example 2: 

EGNS 161150Z 26008KT 0550 R26L/0350 FZFG OVC002 M01/M01 Q0994 BECMG OVC005

A bit of a worse day, so we'll go through it again. 

EGNS: The Isle of Man

161150Z: On the 16th, at 1150Z

Surface Wind 260 Degrees at 8 Knots

Visibility is just 550 meters this time

R26/0350: is a new one. Runway Visibility is given here, showing the horizontal distance down the runway that can be measured. It's only used in poor visibility. Basically it says R26, meaning Runway 26.0350 means that visibility on the runway is actually 350 meters, so less than reported visibility of 

550 meters.

FZFG: This is the precipitation from before. Last time -RA meant light rain. FZFG means Freezing Fog. 

OVC002: This is the cloud coverage again, however this time OVC means overcast, which means the sky is filled with cloud. The 002 means that it's at 200 feet, very low.

M01/M01: Temperature and Dew Point. The M means Minus. It's very cold! 

Q0994: Atmospheric pressure again

BCMG OVC005: This means that it's becoming Overcast at 500 feet. Which is a slight improvement.

That's it. It's a much worse day than the first one, but it's conveyed in the exact same format and works the world over so all pilots can read it. There is no need for language barriers or anything. 

Congrats, you can now read aviation weather like a boss. Or at least a pilot. If you'd like me to go into more detail, let me know below.