This sounds like farmer's insurance on crack.
This is possibly the most absurd financial market I've ever heard of. It reminds me of the betting that goes on in Britain, where almost can bet on almost anything - including weather at shockingly high risks.
It became big on the market thanks to Enron.... Says enough on it's own. No control and can't fully hedge it.
Here's what Wikipedia has to say:
The difference from other derivatives is that the underlying asset (rain/temperature/snow) has no direct value to price the weather derivative.
The first weather derivative deal was in July 1996 when Aquila Energy structured a dual-commodity hedge for Consolidated Edison Co.[1] The transaction involved ConEd's purchase of electric power from Aquila for the month of August. The price of the power was agreed to, but a weather clause was embedded into the contract. This clause stipulated that Aquila would pay ConEd a rebate if August turned out to be cooler than expected. The measurement of this was referenced to Cooling Degree Days measured at New York City's Central Park weather station. If total CDDs were from 0 to 10% below the expected 320, the company received no discount to the power price, but if total CDDs were 11 to 20% below normal, Con Ed would receive a $16,000 discount. Other discounted levels were worked in for even greater departures from normal.
After that humble beginning, weather derivatives slowly began trading over-the-counter in 1997. As the market for these products grew, the Chicago Mercantile Exchange introduced the first exchange-traded weather futures contracts (and corresponding options), in 1999. The CME currently trades weather derivative contracts for 18 cities in the United States, nine in Europe, six in Canada and two in Japan.
Thoughts?