Comparing climates
Lee Poulsen (Fri, 04 Dec 2009 18:20:11 PST)

I noticed what Mike noticed for the two slightly different summer
rainfall patterns back when I was fooling around and made some annual
rainfall graphs of a number of different mediterranean climate region
cities around the world. Mary Sue loaded them onto the PBS wiki way back
when. The comparison graph can be found at:

<http://pacificbulbsociety.org/pbswiki/files/…>

and since it gets kind of crowded at the middle of the summer dry
period, those cities that got more than 1/2 inch or 10 mm of rain during
the driest month are marked. The French and Italian Mediterranean also
had an unusual autumn rainfall peak in October rather than midwinter
like all the other locations.

I made a few other graphs for comparison and contrast that you can also
find on the wiki at:

<http://pacificbulbsociety.org/pbswiki/index.php/…>

--Lee Poulsen
Pasadena, California, USA - USDA Zone 10a

Michael Mace wrote:

--Los Angeles, CA and Perth, Australia have almost identical temperature
profiles (offset by six months). But Perth gets a lot more rain in winter,
and even its summers average half an inch (1.3 cm) of rain a month. In
contrast, LA has five months in summer that average less than 0.3 inches
(0.75cm) of rain per month.

--Valparaiso, Chile is an eerily close match for San Francisco, CA. San
Francisco is a little bit wetter.

--I think there are two different types of Mediterranean climate areas.
What I'll call "Moist Mediterranean" includes South Africa, Western and
South Australia, and southern France/Italy/Greece. They all get a bit of
summer rainfall. "Dry Mediterranean" includes California, Chile, and parts
of the Middle East (Beirut and Tel Aviv, for example). They all have long
periods of virtually no rain in summer.

The implication to me is that if I'm growing South African or Australian
plants, I may need to give them a little bit of summer water.