Anyone who thinks that living in a city means that they will be shielded from the elements is going to be sadly mistaken; a whole host of weather weirdness awaits!
Especially in areas with high-rise developments and/or docks, wind shear can get ridiculously strong- tall buildings can act like giant jets, channelling wind down between them, meaning that the walk down a street ‘against the current’ results in broken umbrellas, messed up hair and dust being kicked up everywhere. A case in point is Canary Wharf in London; don’t go there if you have just been to the hairdressers...
An associated problem with the wind is of course, the rain. If it is windy, precipitation can be felt much more in cities than in more rural locations as it will tend to fall ‘sideways’, spraying into people’s faces. Of course, rain does not absorb well into tarmac, collects in gutters and pools in potholes, meaning that there are many chances for one to get a lot wetter if they are caught out in a rainstorm in a city. Strange but true! (but one can usually duck into a subway). With many major cities and urban areas being located near water such as rivers, ports, coasts etc, then the risks of flooding can be greatly increased. Many cities such as London have precautions in place but a bad flood in a major city can be catastrophic. The recent horrifying events in Japan after the March 2011 earthquake show this in alarmingly clear detail.
Urban areas often have their own microclimates referred to as ‘urban heat islands’- man-made materials tend to retain their heat a lot more than rural landscapes, and energy usage has temperature implications as well. This can affect humidity and fog formation too (San Francisco being a notable example). Smog is something else that can be pre-meditated by hotter locations; warmer air can trap the dirty, smoggy atmosphere. This is a major issue in cities such as Los Angeles and Beijing.
Another major urban weather condition would be a location’s ability to cope with extreme changes to its common climate or weather patterns. In cities and other built up areas this can be greatly reduced. A city can be so dependent on utilities, transport and the like, that if one such function is disabled by the weather than it can result in a complete breakdown of essential services. In December 2010, London virtually shut down because of ‘heavier than anticipated’ snowfall. Heat waves can result in water rationing or hosepipe bans. Adverse weather conditions will obviously affect all cities negatively but some are better at coping than others. Look at locations in tornado hotspots for example.
All cities have their own micro-climate; and it really does vary depending on topography and geographical location. Knowing these idiosyncrasies is a fundamental way of preparing oneself for them on a personal level. One important tip- carrying an umbrella in Canary Wharf is useless!