Is there any hope for our rain year?

As you no doubt have heard, we are experiencing below-average rainfall this year (the official rain year started on July 1 2006, and will end on June 30 2007).

So how dry are we? The chart below gives an indication of the amount of rain received between July 1 of one year and March 31 the following year (i.e., with 9 of 12 rain months counted). On average (counted over 30 years) by March 31 we should have received just over 13 inches (written as 13") of rain. Our annual total is about 14.8", so we typically have received just under 90% of our annual rain by March 31!

This year, we had received just over 8" in downtown San Jose by March 31. So - we are well below average. In fact, the data shows that there have been only eight drier years since the 1948-49 rain year (at least when measured by rainfall received by March 31).

Can we expect a deluge in April and/or May to bring our rainfall up to normal?

To-date in April, almost an inch has been received on campus (see current weather). Climatologically, the wettest April in San Jose during the 1948-2006 period brought 4.55" of rain; that was just last year! Likewise for May, the wettest May (1990) saw 2.38" of rain.

So in conclusion - only if April 2007 is as rainy as April 2006 (which so far it isn't), and if rainfall in May 2007 is record-setting, only then can we come up to normal rainfall for this year. The outlook is not promising.