Rainfall Graphs

Lee Poulsen has been interested in when rain occurs in different countries or parts of countries. This information is useful if you are trying to grow plants in your climate that come from somewhere else. On this page he shares the graphs he has made.

Note: the maps below are available for download but can be large so you may have a few minutes of waiting if you're not connected through highspeed.

Plots of rainfall data from Mediterranean climates created by Lee Poulsen. The first one is for a number of cities around the world and the second one is for cities in Italy.

(From Lee Poulsen:) Because of the discussion on climates, I uploaded a number of other plots I made a couple of years ago when I was investigating possible mediterranean climates. I haven't edited these, so a few details might be missing. If there are no units indicated on the vertical scale, it is most likely in mm. Most of the files are for long-term average monthly rainfall, unless the filename contains the word 'temps' in it, in which case it is probably longterm average monthly temperature. Also, southern hemisphere locations have been shifted so that their summer is in the middle of the plot so that they can easily be compared to plots of northern hemisphere locations. If both northern and southern hemisphere locations are on the same plot, it is most likely that the southern hemisphere locations have been shifted by 6 months so that the seasons align with the northern hemisphere. Finally, you may need to pull out a better atlas to find where some of the locations exist. Or you can locate them online fairly easily using the Global Gazetteer at http://www.fallingrain.com/world/.

These are here because I had the same question Cynthia Mueller had (since I grew up in Austin Texas and still garden there in my parents' yard since my mother is who got me started in growing things and gardening).
Central Texas
Mediterranean and Austin

These are for the Pacific Northwest:
British Columbia

I wanted to see what was going on just to the east of California.
Arizona desert

These proved very educational to me. I ended up dividing South Africa up into these different regions based merely on similar annual rainfall patterns. Some locations are found in several plots since they are on the boundary between two regions. 'medit' is the mediterranean area in the southwestern Cape. 'arid' is on the western side north of the 'medit' region. 'constant' (for nearly constant rainfall all year long) is along the bottom or southern coast to the east of the 'medit' region. 'transition' is where South Africa switches from wet-winter/dry summer (mediterranean) to the opposite dry-winter/wet-summer climate. The remaining two files are examples of the dry-winter/wet-summer climate which occurs in the remainder of the country (mostly the eastern half of South Africa).
South Africa - mediterranean
South Africa - arid
South Africa - constant
South Africa - transition
South Africa - interior
South Africa - coastal

Then I had to do Chile which is like Baja California-California-Oregon-Washington-British Columbia, but in reverse:
Chile - wet
Chile - mediterranean
Chile - arid

Then there are some comparisons between the unique climate of San Francisco and analogous places in Chile. And similarly, with a place near Lisbon in Portugal which someone on one of the lists claimed was almost exactly like San Francisco:
San Francisco vs. Chile rainfall graph
San Francisco vs. Chile temperature graph
San Francisco vs. Lisbon rainfall graph
San Francisco vs. Lisbon temperature graph

Then of course, New Zealand, where they seem to be able to grow everything the mediterranean climate people can grow only better and without a mediterranean climate it seems!
New Zealand

On one of the lists, someone suggested that in addition to the 5 commonly known mediterranean climates of California, Chile, South Africa, Southwest and South Australia (Perth and Adelaide), and all the countries around the Mediterranean Sea plus the Atlantic Ocean around the mouth of the Mediterranean Sea, that we could include the mid-altitude western mountain slopes in Maui and Lanai (but curiously not on the Big Island), and the rain shadow of the Olympic Peninsula in Washington state and of the adjoining southern Vancouver Island in British Columbia, and wondered if the high-altitude parts of eastern or northeastern Brazil might qualify. There really isn't enough data available on the web for me to find out. But it was curious to see a rainfall pattern shifted 3 months from the typical ones seen elsewhere where either summer or winter is the peak rainfall period and the opposite is the peak dry period.
Northeastern Brazil

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Page last modified on February 23, 2010, at 07:38 PM