Rare warmth

For statistics buffs, here is something neat. The 3 pm temperature in BHM is 78 degrees. Even if the temperature did not climb to 79 between observations today, and the high was 78, that puts us in rare territory. The old record for December 10 was broken by plenty. But looking back at high temperatures for every day in the month of December since 1895 (over 3,400 days), there have only been 9 days on which the temperature reached 78 or warmer, for a probability of 0.25%. Below is a graph of the number of times each integer high temperature has been reached in December (1895-2006).

The average high temperature for December has been 55.6 degrees. The median (50th percentile, meaning half of all days have been cooler and half have been warmer) is 55. Also marked are the 10th, 25th, 75th, and 90th percentiles.

Incidentally, this curve fits fairly well into what statisticians call a “normal distribution”, with average 55.6 and standard deviation of 10.2 degrees. Standard deviation gives an idea of how much the highs have varied from the average.

And yet, take a look at temp contours across the southern U.S. at 3 pm. What a front.

There is no reason we shouldn’t be about as warm tomorrow and Wednesday, unless an area of clouds rolls in and holds temps down. But, like James mentions, colder air comes in by Friday and the weekend.

Category: Uncategorized