Causes. Although doctors don't know what causes ITP, they know that it happens when your immune system -- your body's defense against disease -- doesn't work right. Your antibodies, which are supposed to attack infections, instead mistakenly destroy your blood platelets.
Although not as strong as the Asian monsoon, the cycle is typical of monsoon seasons worldwide. The monsoon season begins on June 15 and ends on September 30, but the storms peak between mid-July and mid-August. On average, about half of Arizona receives about half of its annual rainfall during the monsoon. However, rainfall can vary tremendously between distances of just a few miles.
Climate of the Southeastern Arizona Planning Area. 1  Annual average precipitation in the planning area is 14.7 inches, with over 52% coming in July, August, and September (Figure 3.0-6). This planning area receives the most summer precipitation in the state because of its proximity to the core monsoon region in Mexico.