The Danish Meterological Institute also serves the interests of our bicycle culture. They've done a spot of research regarding how likely it is for you to get wet on your daily commute. Important research for any true bicycle nation. Here's the rub, translated roughly from the DMI's article: Let's take a fictional person, let's call her Kassandra. Kassandra lives a little north of Copenhagen and rides every to work every day between 07:25 and 07:55 and back again between 15:35 and 16:05. Kassandra doesn't mind a little light showers, but if the intensity increases to over 0.4 mm over 30 minutes (light rain), then she thinks it is too wet. Kassandra works five days a week and has weekends and holidays free. That gives her 498 trips between September 2002 and the end of August 2003. How often does Kassandra get wet either to or from her job that year? The answer is, in fact, rarely. On those 498 trips it was only 17 times. That is only 3.5% or on average 1.5 trips a month. On the graph the green means dry trips and the blue means wet trips.
The numbers on the left (and right) are the number of bike trips per month (two per day).
So, basically, it's good news. In any climate the rain usually falls at certain times of day. Commuting at the same time every day gives you a steady statistic to work with. If you ride at different times every day, you're on your own. The Dutch, I seem to recall, have reached similar conclusions, based on their precipitation data. Here's a link to