Mediterranean Climates--Rainfall

Mary Sue Ittner
Mon, 17 Mar 2003 10:46:50 PST
A number of years ago (10/00) Lee Poulsen researched the rainfall in some 
of these climates and created a chart in pdf format. I have uploaded it to 
the wiki for those of you who were not around to get it then.…

Here are a few summary comments from Lee I saved from that time:
"Anyway, a few things I noticed were:

1. The Perth area and Adelaide area of Australia and the Cape Town area of 
South Africa have much wetter summers than the other Mediterranean areas. 
However, so does the region from Marseille, France to Rome, Italy. This was 
a surprise to me. It was also interesting to see that Marseille and Rome 
both have their peak maximum rainfall in October (mid-autumn) rather than 
mid-winter like everywhere else, even though their peak minimum rainfall 
occurs in mid-summer (July, or January for the southern hemisphere).

2. The mid-highland areas on the dry side of the Hawaiian islands of Maui 
and Lanai seem to have a temperature and rainfall profile that to my 
eyeball looks just like any other recognized Mediterranean climate region. 
(Although their peak minimum rainfall seems to occur
one month earlier than everywhere else.) I suspected this after having seen 
all the banksia and protea and eucalyptus growing at that elevation in 
Maui. I wonder if there are any other islands or highland areas in the 
subtropics with similar conditions that are also effectively Mediterranean. 
(This would give us "six" Mediterranean climate regions in the world...)

3. Other than the 6 month shift and the higher summer rainfall in 
Australia, I was surprised to see that Perth and Beirut, Lebanon have 
almost identical monthly rainfall patterns. I wouldn't have guessed that 
those two places were so climatically similar.

4. This isn't shown in the plot, but I was surprised at how very rapidly 
the "Mediterranean" pattern disappears as one moves away towards the 
northeast or east from Cape Town, South Africa, or towards the north, 
northwest, or west from the French Riviera into areas that aren't 
Mediterranean---unlike the analogous situation in California and Baja 
California, or in Chile, or in the Perth and Adelaide areas of Australia, 
or in the rest of the Mediterranean basin, (or as one heads north from Cape 
Town), where the rainfall pattern gradually merges into a different climate 
rainfall pattern(most often a desert-like one).

5. Based on the rainfall patterns for different parts of New Zealand that 
are easily available, I can't understand why they can grow so much 
Mediterranean climate stuff there so easily. Auckland, Wellington, and 
Christchurch are all much wetter year-round than the "standard" 
Mediterranean regions.

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