Corn crops withering due to lack of rainfall at Perryton, Texas [Getty Images]

It has made for great headlines in the United States for more than a month, but it had to end eventually. In a country which still clings to the largely defunct Fahrenheit temperature scale, Dallas, Texas had reported daily temperatures in excess of the magic 100 degrees Fahrenheit mark every day since 2nd July.

In Celsius, which is the recognized scale across much of the rest of the world, 100 degrees is the equivalent of a much less noteworthy 37.8 degrees. Nevertheless, the breaking of the 100 degree mark was a significant indicator of the extent of the heat wave which has clung on for so long across southern states.

So when temperatures on Thursday 11th August 'only' reached 97 degrees (36.1 degrees Celsius), it brought to an end a sequence of 42  '100 degree plus' days, just two days short of the record set in 1980.

Yet, despite the loss of the heat wave headline, temperatures across many southern states are likely to remain significantly above average for the foreseeable future.

Of even greater significance than the temperatures, has been the extent of drought which has gripped much the south for many months. The combination of high temperatures and drought made July 2011 the most extreme since 1910, according to the National Climatic Centre’s Climate Extremes Index.

The onset of the so-called southwesterly monsoon rains in the southwest of the U.S. was significantly delayed but by August there was some welcome rain.  Del Rio, Texas, close to the Mexican border, recorded 114 millimetres of rain in the 24 hour period ending at 06 GMT on Friday.

Unfortunately, the rainfall deficit across many of these southern states is such that such heavy downpours are required on a much more widespread and frequent basis if the drought is to end any time soon.

Resistance to the idea of anthropogenic (man-made) global warming is probably more strongly entrenched in the United States than anywhere else. It will be interesting to see how the country adjusts its views on this thorny subject should drought and other extreme weather events continue with such frequency over the next few years.

Source: Al Jazeera