Even though the southwest is experiencing drought conditions, 2015 was the rainiest year in the last nine years during which I recorded rainfall at my house.
Since mid-2007, I have been measuring and reporting daily rainfall at my house on the west side of Tucson, Arizona. This is part of the RainLog.org program run by SAHRA, “Sustainability of Semi-Arid Hydrology and Riparian Areas.”
Tucson has two rainy seasons: a winter season which may or may not have much rain, and the summer monsoon which gives us the majority of rainfall in the region. During the winter, our weather comes from the west and storms may be sucked dry as they pass over the Sierra Nevada of California. During the summer, our weather comes from the southeast with winds bearing moisture sucked out of the Gulf of Mexico and the Gulf of California.
During the summer monsoon, desert heat and orographic uplift from mountain ranges turn that moist air into thunderstorms. In Tucson, much of the rain occurs on the east side of town because of the air flow direction and orographic uplift over the Catalina Mountains. We who live on the west side of town get what is left over.
Here are the numbers.
In 2015, I recorded 14.32 inches of rain. The next rainiest year was 2008 with 12.09 inches. The dryest year was 2013 with 7.95 inches. The graphs below from RainLong show how rain occurred during the year (there are two graphs because Rainlog can plot only five years at a time).
Here is the total rainfall recorded in inches since 2008:
As I write this on January 2, 2016, El Nino driven rain is forecast for every day next week.