What is the average rainfall of French Guiana?

Why are daily rainfall records so low for so many areas of the U.S.?

• I live along the Gulf Coast of Texas, and have seen days in which 10 inches of rain fell. I have been looking at the daily rainfall records for U.S. cities, and am very suprised to find out how low they are, even in southern cities. A good example are the 3 major cities in Ohio, Columbus, Cincinnati, and Cleveland - never have any of those towns had a day of 5 inches in a day. Pittsburgh until 2004 never had a rainfall of over 4 inches! The midwest has a little more extremes when it comes to extreme daily rainfall, most areas have seen one day with a 7 inch rain, but the northeast and mid atlantic - except areas right on the coast have only a 5 to 6 inch daily rainfall record. Philadephia's wettest day is just 6.60 - and until 1999, they never saw more than 5 inches in a day! Even in the southeast, cities like Atlanta, Nashville have only had one day in which 7 inches fell. Orlando Florida has never had more than 8 inches in one day. Contrast this to cities like Houston, New Orleans, Baton Rouge, and Mobile, which have all seen several days in which over 10 inches of rain has fallen! I know that extreme rainfall is not just limited to a tiny area of the country from South Texas to 30 mile inland on the gulf coast!

• Answer:

  The totals from Houston, NO, BR, and Mobile were probably during a hurricane or slow-moving tropical storm. And the closer a city is to the Gulf, the higher moisture content in the air. Remember that official rainfall totals are from a single rain gauge at an official reporting location. In my own small town, I've seen blinding rain downtown and none at my house a mile away on the same day. Rainfall totals are almost like an average of an entire city. So if a city has a 5-inch total, that may mean that one part of town had 3 inches and another 7 inches.