It's officially a record: 2012 was Madison's warmest

How did we warm thee? Let the National Weather Service measure the ways. The perhaps least surprising weather statistic for 2012 was the one everyone had to wait for until its very last day. Yes, the "mean average" temperature in Madison for the year, 51.3, was the warmest on record. The previous record was set 81 years ago, in 1931, when the mean average was 51, according to Morgan Brooks of the National Weather Service office in Sullivan. Madison's monthly temperature mean — which is an average of the averages, said Brooks — was above normal for every month except October and September. In other numbers for Madison, 2012 ranked second in weather history for the number of days with temperatures 90 or above, at 39. Only 1955 recorded more, with 40. If you want to push that, Madison had four days above 100, a tie for fifth. In 1936, there were eight days above 100. While those many hot days of summer contributed to the record, it was the unusual heat wave last March that weighted the final average, said Brooks. The average temperature in Madison last March was 50.1 degrees, nearly 5 degrees warmer than second place, or 45.2. Compare that with the average monthly temperature for March, at 33.7 degrees, and you start opening record books. The 51.3 degree question then is: How come? "A lot of the warmth had to do with where the jet stream sets up," Brooks said. "In March we had a ridge of high pressure that just stationed itself right over us and didn't move." That prevented the cold air from the northwest from visiting, she said, and influenced the summer heat wave, too. While Brooks' office deals out seven-day forecasts, the NWS climate prediction center focuses on longer-range forecasts. Asked if this summer will be another record-setter, Brooks did not venture far out on the limb: Of the three choices — above normal, normal and below normal — "there is an equal chance for all three." The weather service lists temperature statistics as "mean average," a term Brooks defined as "a way to say average average. "In a month, each day has an average, and then for the month, there is an average of all the daily averages," she said. "For the year, all of the monthly averages are averaged to get the 51.3," she said. Milwaukee did not break its records for warmest year, but it hit 51.9, high enough to tie the 1931 mark.