Are Record Temperatures Abnormal?

That is a total of 365,000 high temperature records and 365,000 low temperature records.  During the second year of operation, each day and each station has a 50/50 chance of breaking a high and/or low record on that date – so we would expect about 182,500 high temperature records and about 182,500 low temperature records during the year.

In the third year of the record, the odds drop to 1/3 and the number of expected records would be about 121,667 high and low temperature records.

In a normal Gaussian distribution of 100 numbers (representing years in this case,) the odds of any given number being the highest are 1 out of 100, and the odds of that number being the lowest are also 1 out of 100.  So by the 100th year of operation, the odds of breaking a record at any given station on any given day drop to 1/100.   This mean we would expect approximately 1000 stations X 365 days / 100 years = 3,650 high and 3,650 low temperature records to be set during the year – or about ten record highs per day and ten record lows per day.

This provides the news media lots opportunity to get hysterical about global warming every single day – even in a completely stable temperature regime.  The distribution of temperatures is Gaussian, so it won’t be exactly ten per day, but will average out to ten per day over the course of the year. In a warming climate, we would expect to see more than 10 record highs per day, and fewer than 10 record lows per day.

In a cooling climate, we would expect to see more than 10 record lows per day, and fewer than 10 record highs per day.  The USHCN record consists of more than 1000 stations, so we should expect to see more than 10 record highs per day.  Throw in the UHI effects that Anthony and team have documented, and we would expect to see many more than that. So no, record high temperatures are not unusual and should be expected to occur somewhere nearly every day of the year.  They don’t prove global warming – rather they prove that the temperature record is inadequate.

No continents have set a record high temperature since 1974.  This is not even remotely consistent with claims that current temperatures are unusually high.  Quite the contrary.

http://www.infoplease.com/ipa/A0001375.html

Here is the code discussed in comments:

// C++ Program for calculating high temperature record probabilities in a 100 year temperature record

// Compilation :  g++ -o gaussian gaussian.cc

// Usage : ./gaussian 100

#include <iostream>

main(int argc, char** argv)

{

int iterations = 10000;

int winners = 0;

int years = atoi(argv[1]);

for (int j = 0; j < iterations; j++)

{

int maximum = 0;

for (int i = 0; i < years; i++)

{

maximum = std::max( rand(), maximum );

}

int value = rand();

if (value > maximum)

{

winners++;

}

}

float probability = float(winners) / float(iterations);

std::cout << "Average probability = " << probability << std::endl;

}