DaytonDailyNews.com

February 2007 has gone into the books as the second coldest month for the Dayton area. Since records have been kept for Dayton (about 125 years), only February 1978 was colder. The new top-five coldest Februaries:

1. February 1978: 16.9 degrees

2. February 2007: 18.5 degrees

3. February 1984: 19.1 degrees

4. February 1947: 22.0 degrees

5. February 1906: 22.1 degrees

February's normal average temperature is 30.3 degrees, making this year about 12 degrees below average. Twelve degrees away from what is typically expected in a given month is extreme.

Most months are within a few degrees of average, and ones that would be characterized as unusually warm or cold fall somewhere between 5 and 7 degrees away from average.

If it weren't for a return to seasonable conditions the last week of the month, 2007 likely would have ended up number one.

Extreme stretches can often end with extreme weather. We certainly had some late last week with all the rain and snowmelt combining to produce some of the worst localized flooding many had seen around here in a long time.

For those of you who dealt with flooding to your home, I have some good news: That was perhaps a worst-case scenario. All the ingredients were in place for it to be as bad as it was thanks in part to the tremendously cold stretch we endured. Let me explain.

About 1 to 1½ inches of rain fell last Thursday. That on its own may have produced some damp basements, but certainly not the flooding we saw.

So how does the cold stretch from mid-January and February come into play? We also rose to 50 degrees last Thursday. It was not only our first 50-degree temperature in six weeks, but only the fourth time we rose above the 30s in the previous six weeks.

During that very cold six-week stretch, we also accumulated about 2 to 3 inches of liquid sitting above the ground in the form of snow and ice. We did rise above freezing from time to time, but most of the snow and ice just melted and refroze. Enter last week's storm. When you combine the rainfall, and the melted snow and ice it was like the equivalent of a 4-inch rainfall. And the ground was still frozen, so none of the water could be absorbed. The result was some pretty serious flooding.