I got my first air quality warning from airtext.info today, after three whole months of London air quality giving no cause for alarm!
The london air quality network, who recently released a popular updater for iphones have reported a couple of moderate particulate readings as a result of light southeasterly winds bringing particles over from Europe coupled with the build up of traffic emissions during a cold and foggy night over here. Their highest readings tend to coincide with guy fawkes night!
Anyway apart from thinking about how dirty London is, here’s a nice rose plot of the 2009 average wind direction (in degrees from north) and speed (in meters per second) of readings taken from the falconwood site. I had always thought that the prevailing wind came from mexico (roughly 210°-240°), and usually the kites in blackheath do catch that breeze… but judging by the data (which are apparently to interpreted with some caution due to obstructions) the easterly wind (90°) seems to be the strongest, presumably it whistles up the thames all the way from siberia, brrr!
** Update ** for a bonus, which is mainly useful to those who are wondering where a case of what the daily mail infamously referred to as ‘le/der stink‘ might be coming from, here’s an updater that retrieves the wind data for the last seven days.