Monsoon season is officially here!

Traditionally, the start of the monsoon season in the southwest US was determined by “three consecutive days when the average dew point temperature was greater than 54 degrees Fahrenheit in Tucson” (Guido 2010). A few years ago they changed to a date: 15 June. Why? I guess the dew point determination was too scientific or something – humans prefer arbitrary dates (or read Guido’s article for an alternative explanation).

I snort and snicker each year when people talk about the monsoon arriving mid-June.

Yeah right. Have you been outside? It’s 100 degrees and approximately 0% humidity!

Then it happened.

Friday evening (14 June), dark clouds gathered and we were treated to a thunder and lightning show. But no rain – as I’d expect in June.

Oh, but the monsoon officially starts 15, not 14 June!

And that was when the rain arrived, Saturday afternoon.

This could have been taken 15 June 2013, but was actually taken 3 July 2012.

There is nothing more spectacular than the first monsoon storm of the year, especially after a dry winter and spring. We stood outside in the rain until the first of it stopped and we were cold and wet (YES, I said COLD in ARIZONA in JUNE). Although we’re probably doomed to several more weeks of dry before the storms come regularly, I’ll take it.

This also didn’t happen yesterday, but could have, since Henry (male western diamond-backed rattlesnake) was again sitting next to a pond during the storm. We were just too excited to enjoy the rain instead of running around taking pictures 🙂

Want to learn more about the monsoon? Check out this article (it has graphs!)
Guido, Zack. 2010. Understanding the southwestern monsoon. Southwest Climate Change Network. Accessed 16 June 2013 at