Fog and Rain

I was thinking of writing a post about our climate in the Bruce Peninsula in Ontario.  Specifically I wanted to write about the fact that it is rather on the dry side, despite the influence of the Great Lakes.  Before I started, I thought I should check how much rain we actually get in a year.  I discovered we get a lot more than I thought. However, it would appear that the amount of rain is not as important as how it falls, especially when you compare how much rain falls different places in the world.

Field to the east of the house in October

Some yearly rainfall statistics are quite surprising. For instance, Dallas, Texas, gets 942 mm of rain a year, while London England gets 592 mm! In fact, most European cities get less rain than eastern North American ones.

Toronto 762mm     Madrid 431mm
Chicago 863           Berlin and Rome 583
Boston 1067           Paris 635
Vancouver 1107     Amsterdam 787           
New York 1194      Bergen 2075

Vancouver, well-known for its constant rain, gets less precipitation than New York! Of course it must have to do with how the rain falls. Vancouver specializes in drizzles and does not get any cyclones that dump huge amounts of rain, whereas New York gets them regularly.

With an average yearly precipitation of 684mm, it would appear that the Northern Bruce Peninsula is indeed slightly drier than the average for the region (828mm for Minneapolis, 795 for Detroit, 862mm for Chicago).  Besides, since much of our rain falls in autumn, as the numerous recent downpours show, we tend to have dry summers. In fact, some summers were very dry in the 1990s.

Fog rolling in at sunset

I think what helps our climate a lot from a gardening point of view is our numerous fogs. Probably because we are surrounded by the Great Lakes, we often have fogs at night and in the morning, which make a big difference for plants when there is no rain. We do not get a lot of fog in the daytime, but many evenings in the growing season, you can see fogs rolling in just before sunset. These fogs seem to stay around much of the night, because at dawn they are usually still lingering. Plants can soak up the moisture.

Lingering fog in the morning

Some fogs are spectacular. For instance they can be very dense but not much more than a meter high. Walking in it, you feel you are on top of a cloud. You don't see anything on the ground but everything above the low lying clouds is perfectly clear.

Usual evening fog moving in - field East of the house

These fogs are a nuisance when driving at night. It will be perfectly clear until the road goes down into a hollow, and suddenly you have no visibility at all until you reach slightly higher ground.