The least gripping weather
Most big news stories about the weather are to do with extremes. Snow falling metres deep, hailstones the size of footballs, winds faster than jet planes: these are the stuff of weather legend. But spare a thought for one record that is too rarely explored. What about the record for crushingly dull weather?
Spare a thought for the Englishwoman who moved to Arizona a few years ago. On the first Monday in her new job, she exclaimed to her colleagues: “What a nice sunny day.” She did the same thing on Tuesday and on Wednesday. Then someone finally told her that everyone thought she was mad. It is sunny every day in Tucson, they told her, and on the rare occasions when it is not, you can say something about it.
Well,Tucson weather is indeed pretty dull, with the temperature wafting from the teens to the thirties and back again in a highly regular fashion. There is almost always about 250mm of rain, mostly in the autumn. But in recent years, the city's claim to true dullness has been blighted by an almost newsworthy drought Another candidate might be the South Pole. As a desert, it has only a few centimetres of rain – or its snow equivalent – per year. The blizzards there mostly pick snow up, throw it about, and then drop it again. Although the temperature varies from, say, -60°C in winter to -30°C in summer, both are well below freezing anyway.
However, to find true climate dullness, it is necessary to head into more equatorial regions. In the Amazon, it is completely typical for clouds to build through the day until a hefty storm gets you in the afternoon. Although some times of year are rainier than others, it rains all year round. The Amazon basin is also pretty homogeneous in terms of weather despite being bigger than most countries.
But the climatic dullness record is held by Jakarta, capital of Indonesia and of unremarkable weather. A look at the data shows that you should expect “discomfort from heat and humidity'in January, December and all intervening months. In April and May, the average minimum temperature is 24°C, while in the other ten months, it slumps to 23°C. The average maximum ranges from 29°C to 31 °C. Even the records since data gathering began only range across 2°C for the lows and 3°C for the highs through all twelve months of the year.
The reason for this stability is that the equatorial regions are marked by a strong upward airflow. Because the area is heated at more or less the same rate by the Sun all year round, conditions are very constant. There is a rainy season and a dry season, but even these terms are comparative.The rising air cools as it ascends and a decline in its ability to hold water is inevitable.The result is rain for those below. There are plenty of places where the weather is very predictable, such as the centres of the American or Eurasian land masses, where hot summers and freezing winters are almost the rule. But the tropics are the place where variation in the weather is all but unknown.