The Arizona Monsoon-The Origin of the Term

After 100 days of dry, the phenomena known as “The Arizona Monsoon” has finally arrived with a vengence!

In 1965 I moved to Phoenix, Arizona with my family.  My father took the job of Meteorologist in Charge for the National Weather Service, now known as National Oceanic and Atmospheric Administration (NOAA).  We moved there in the winter and other than I thought I could swim in our new swimming pool in January, I knew nothing about Southwestern weather!  As summer approached, besides the pool feeling much better, I started realizing that it was pretty hot and dry and then….DUST!  The craziest phenomena associated with the Monsoon is the Haboob (an Arabic name that means Dust Storm).  Sometimes there were big drops of rain to speckle your car and sometimes there weren’t. Nevertheless, within a week or two the real thing would usually came.  Large towering thunderstorms that lit up the desert at night.  Impressive.

A Wall of Dust

A Wall of Dust

So how did the term Arizona Monsoon become a part of our vernacular?

Monsoon defined by the first observers – stated “the term monsoon, may be applied to any wind system in which there is a reversal of the prevailing wind direction between winter and summer.” The word monsoon is derived from the Arabic “Mausin” or from the Malayan “Monsin” which signifies “season”.

I would like to say that my father started the term “Arizona Monsoon”, but he didn’t.  What he did do was find a research paper completed by Reid A. Bryson and Bill Lowry et. al. from April of 1955 called “The Synoptic Climatology of the Arizona Summer Monsoon”,  wherein it was noted that the change in wind patterns from winter to summer that brought in moist air from tropical Mexico was similar to the Indian or West African Monsoons.  With this he began the dialogue with the various television stations and news agencies and slowly but surely the term Monsoon became a normal part of an Arizonans term for the summer thunderstorm season.  There are still people out there that disagree that we should be using foreign names for our weather terms, but so be it.  It’s a lot easier to say “Monsoon” than to say the southwestern summer thunderstorm season!

You Know the Monsoon is Here When You See These!

You Know the Monsoon is Here When You See These!

Three days of 55 Degrees Dew Point

One thing my Dad did do was track what the official start of the Monsoon season was.  His analysis of years of data was that the first string of 55 degree dew points over a three day period usually brought upon the season.  This was used for years by the television meteorologists as the criteria to go by.  There was a lot of hype over those three days and  NOAA Meteorologists a few years ago decided to end the suspense by introducing the June 15 to September 15 period as the official “Monsoon Season”.  I’ve noticed that many of the Television Weather people still like to look at the Dew Point as an indicator of whether or not we are there yet.  So whether it be June 15th or July 8th when the rains start, it is usually because the 55 degree dew point has been reached!

The future of the Southwestern Monsoon

A recent article in ScienceNews talks about with climate change the monsoon season could heat up creating stronger rainy seasons over the long term.

The problem will be like everything related to our Monsoon Season, how much rain will fall, or how little and where will it happen or not happen?!

“In many regions, farmers and others depend on summer monsoons to deliver more than half the year’s rain. The researchers can’t say whether stronger monsoons will result in more water overall for these areas, says coauthor Yemane Asmerom, a geochemist at the University of New Mexico in Albuquerque. Warmer air holds more moisture, which leads to more rain. But, he says, warmer temperatures also increase evaporation in dry places such as the Southwest.

One outcome of stronger monsoons could be fewer but heavier fits of rain, which could unleash flash floods, says climate scientist Andy Turner of the University of Reading in England. But local factors will probably cause regional differences in monsoon. For example, he says, the concentration of soot and other aerosols or land surface features might weaken monsoons in some areas, offsetting some of the strengthening caused by warmer temperatures.”

Read the full ScienceNews article at the following link;

Here area  sampling of photos taken last week during the wettest outbreak of storms this season!

The Rains can be over an isolated area

The Rains can be over an isolated area

Or spread rapidly over a large area!

Or spread rapidly over a large area!

Storms like these will make the washes run.

Storms like these will make the washes run.

When the base is dark you know it's wet.

When the base is dark you know it’s wet.


Fair Weather Cumulus may lead to something else.

Fair Weather Cumulus may lead to something else.



About rsingram

Environmental Specialist, Disaster Reservist, Certified Professional in Erosion and Sediment Control, Para-Archeologist
This entry was posted in Arizona Monsoon, Climate Change, Environment and tagged , , , . Bookmark the permalink.

2 Responses to The Arizona Monsoon-The Origin of the Term

  1. GeorgeS says:

    That was a very interesting article. I had no idea your father was involved in all that. Funny thing is I moved here in 1967 to go to ASU as a freshman in Engineering. Our family came to Phx because my father accepted a job as the superintendent of the Arizona State Hospital. After I graduated in engineering I worked at AiResearch and have been in AZ ever since.

    I’m interested in weather and climate science just as kind of a hobby.

    I think they made a mistake changing from the definition of Monsoon season from 3, 55 DP days to June 15th to Sept 15th. My own non scientific observation is that it usually starts on the 4th of July but the DP def is better IMO.

    Good article, Thx for posting it.

  2. Susan Trumbull says:

    Very interesting article, Rob. Liked the photos and descriptions too. When we were going through the southern US we would see different (for us) cloud formations etc. and wished we had some clue of what they meant…..Southern weather is scary, but even AZ weather can be baffling. Happy New year!

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