Q Is there such a thing as a windy season?

A After a rather cloudy and blustery start to May, we were recently asked if there are certain particularly windy times of year here in Madison.

Of course, a windy day can come along just about any time of year (the record gust of 83 mph in Madison occurred in June 1975) but the climatology suggests that March and April are the windiest months of the year with average wind speeds of 11.3 and 11.4 mph, respectively. November through February are not far behind logging a four-month average of 10.5 mph.

That it's windier during the cold season is not surprising as that time of year is characterized by the highest frequency of mid-latitude cyclone activity. Mid-latitude cyclones are large in scale, covering several states simultaneously, and are often associated with very large differences in sea-level pressure over small distances. It is these pressure differences that drive the wind.

The particular maximum in March and April may reflect the fact that late winter and early spring storms have a higher chance of containing thunderstorms that can locally enhance the winds. It may also be that on a sunny March or April day the daytime heating contributes to a slightly breezier day than might be observed on a similarly sunny day in the depth of winter.

It is interesting that the windiest month (April) occurs when plants are most in need of assistance in spreading pollen and reproducing. The power of evolution!

- Steven A. Ackerman and Jonathan Martin, professors in the UW-Madison department of atmospheric and oceanic sciences, are guests on WHA radio (970 AM) the last Monday of each month at 11:45 a.m.