MONSOON ! ~ What is it? ~ How Does It Affect Sedona and Arizona?

Monsoon!

An Arizona Summer Phenomenon

Bell Rock Sedona – Thunderhead Increasing

A similar article was featured on ActiveRain in 2019 – The largest and most active professional social network in the real estate industry…

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Information on Monsoon – Sedona, AZ – First of all, there is no need to add season at the end of Monsoon because Monsoon is a season. Monsoon affects the western and southwest states because the pattern of the weather changes, as noted below.

How Long Is The Monsoon In Arizona?

Monsoon officially starts on June 15th and ends on September 30th. However, most of the rain comes from the middle of July through the middle of August. This is one of the reasons that the temps in Sedona are less harsh during July and August. The average rainfall in the state of Arizona is around 12.5 inches. The Sedona area gets more than the average rainfall. We have had as much as 26 inches (2016) and as low as 13.66 inches (2014). We had our lowest total ever of rain and snow in 2020. Only a trace of snow and 8.15 inches of rain. Sedona has shown improvement in drought conditions. In fact, the Coconino Forest has lifted a campfire ban because of all the rain we have received. See the actual precipitation chart on Sedona-Weather.com.

What Creates Monsoon Conditions?

Weather enthusiasts and forecasters, and wonks look to the dew point to tell if monsoon conditions exist. The dew point must be about 55º for thunderheads to start development. The dew point indicates how much moisture is in the air. At this point, the air cannot hold water in gas form, and the gas will then turn to liquid form creating water droplets. The water droplets create fog or precipitation. Prior to officially declaring a calendar season for monsoon, the season would be declared when there were three days at a dew point of 55º.

2016 – Record Rain Totals

In 2016, the monsoon had 9.65 inches of rain recorded at our station. Coupled with over 7 inches of rain and 7.5 inches of snow, we had a year-end total of 25.92 inches of precipitation.

So Far in 2022…

The first six months in 2022 had 2.46 inches of rainfall AND 5 inches of snow. Most of that snow came in February!

Since 2010, our backyard weather station has recorded an average of 5.8 inches of rain in July and August combined, so every year, we look forward to the monsoon. In 2019, we had El Nińo conditions. This caused our summer climate conditions to change. There was less cloud cover and less rain which caused warmer temperatures throughout the summer months. This is an a-typical season. As noted below, the normal Monsoon pattern brings moist air from the south.

June is usually a pretty dry month with very little cloud cover. So the temps remain high. In fact, June is usually the warmest month of the year. However, in 2022, we had the most rain we have ever had in June. The rainfall was .79 inches. The high temperature for the month was 103.9 this year versus 112.3 in 2021! The average temperature was 1 degree less than in 2021. The additional cloud cover, which acts as a blanket, probably kept the temperatures from going lower.

Preparation For Monsoon

One quick note – Because it is our rainy season and the chance of lightning during a thunderstorm could knock out power, take some time to have things ready to go:

Know where the flashlights and candles are for easy access.
Keep your cell phone charged.
Clean out gutters – drains – culverts – rain ditches, and any other natural path water may take during a sudden downpour.
You should have sandbags prepared to divert rain that may cause flash floods.
Thin trees close to your home. Many trees fall during high wind conditions.

What Is Monsoon?

It seems that Southern Arizona, the White Mountains, and the Phoenix metropolitan area known as “The Valley” get the brunt of the monsoon effects. It is amazing to see the haboob (desert wind storms) kick up and tower thousands of feet in the air moving through the valley. Those storms are the precursor to the rain and massive storm cells that develop from the moisture in the warm air coming off the Gulf of Mexico. Generally, massive amounts of rainfall create downdrafts that push the air out from the center of the storm, which produces a dry wind that kicks up the dust and dirt.

Seasonal Weather Patterns

During summer, weather patterns change. Storms that travel from the arctic (Alaska) down through Canada and the lower 48 create our winter storm pattern.

In the summer, the pattern shifts to the south. Hurricanes, storms, and moisture travel northwest from the Gulf of Mexico through Mexico, Texas, New Mexico, and Arizona moving all the way to California. We also get moisture coming from the Gulf of California, traveling directly north. Lots of moisture and an occasional hurricane come up from the coast of Baja, California, and push northeast into Arizona.

Northern Arizona

In Northern Arizona, we get a lot of cloud cover, and the storms move through but usually don’t drop a lot of rain here in Sedona. Though in Flagstaff, it is quite a different story! The area of Sedona seems to be protected. By that, I mean that most of the rain falls elsewhere before it gets to our little city. But when we do get rain and storm cells, it is a big deal around here.

In 2014, Sedona got 7.73 inches of rain from July through September. In 2013, there were 8.18 inches of rain in the same time frame. Flash flooding can happen because many of the streets are sloped, leading up to the red rocks. There has been much improvement made in our drainage system to be able to handle the additional water flow, but during an intense storm, there is no place for the water to go, and mud and rocks can travel across roads to find the path of least resistance. Do not travel through a road where water is more than 4 inches deep. A car can be swept away easily.

Southern & Central Arizona

In Southern and Central Arizona – 2014 will be remembered as the “Monsoon of the Century.” All future monsoon activity will be measured in terms of 2014. There were three major hurricanes that affected the weather in the southern half of the state. This caused a deluge, and many towns and neighborhoods suffered tremendous flooding damage due to flash floods, hurricane wind, broken canals, and water that had nowhere to go. Many long-time residents had never seen a deluge like we had that year. Sky Harbor Airport had a record rainfall of 1.59 inches and exceeded the all-time record set back in 1903.