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

Monsoon!

An Arizona Summer Phenomenon

Bell Rock Sedona – Thunderhead Increasing

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

2026 Sedona Monsoon Recap

A Hot, Slow Start — Followed by a Very Wet September

The 2026 Sedona monsoon was a season of extremes. It began exceptionally hot and dry in June, became more active in July, backed off again in August, and then finished dramatically with 4.05 inches of rain in September, aided by tropical moisture associated with Hurricane Polo.

June was remarkably hot. We received only 0.18 inches of rain, while every one of the month’s 30 days reached 90º or higher. Fourteen days exceeded 100º. This was only the 2nd time in June since I began tracking these temperature categories in 2017 when every day reached at least 90º.

July finally brought signs of a more typical monsoon. Rainfall increased to 2.22 inches, with six days recording precipitation. The heat continued, however, with 22 days over 100º and 28 of the month’s 31 days reaching 90º or higher.

August remained extremely hot while rainfall decreased to 0.92 inches. The month’s average temperature reached 81.9º, making it the warmest August I’ve recorded since my weather records began in 2010. We experienced 24 days over 100º, and the temperature reached 111.2º, our hottest reading of 2026.

Then came September.

September produced 4.05 inches of rain—more than June, July and August combined. Tropical moisture associated with Hurricane Polo contributed additional rainfall during the final days of the month, giving Sedona’s 2026 monsoon a very wet finish.

Despite the rain, September remained warm. 22 days reached 90º or higher, including three days over 100º, and the monthly mean temperature of 72.8º was 1.3º above Sedona’s historical September average.

🌧️ 2026 Monsoon Rainfall

• June — 0.18 inches
• July — 2.22 inches
• August — 0.92 inches
• September — 4.05 inches
• Total June–September — 7.37 inches (This ranked 4th since 2020)

For comparison, the same four months in 2025 produced 9.57 inches of rain. So even with September’s impressive finish, the 2026 monsoon produced 2.20 inches less rainfall than 2025 at our location. In the last 7 years, 2021 had the most monsoon rain at 9.61 inches.

What made 2026 particularly memorable was the combination of extreme heat and uneven rainfall. The monsoon struggled to get started in June, July brought some relief, August turned exceptionally hot, and September accounted for 55% of the season’s total rainfall.

The monsoon officially ended September 30th, but the 2026 season certainly saved its biggest rainfall story for last, because of Hurricane Polo off the Pacific Coast of Baja.

All statistics are from weather station KAZSEDON183, located in the Cottages at Coffeepot in Soldiers Pass, West Sedona.

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Information on Monsoon – Sedona, AZ – First, there is no need to add “season” after Monsoon because Monsoon is a season. Monsoon affects the western and southwestern states because weather patterns change, as noted below.

How Long Is The Monsoon In Arizona?

Monsoon officially starts on June 15th and ends on September 30th. However, most rain comes from mid-July through mid-August. This is one reason Sedona’s temps are less harsh in July and August. Arizona’s average rainfall is around 12.5 inches. The Sedona area gets more than the average rainfall. We have had as much as 33.15 inches (2025) and as low as 8.15 inches (2020). See the actual precipitation chart on Sedona-Weather.com. You can compare this to previous years back to 2010.

What Creates Monsoon Conditions?

Weather enthusiasts, 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 developing. The dew point indicates how much moisture is in the air. At this point, the air can no longer hold water in gas form, so it turns to liquid, creating water droplets. The water droplets create fog or precipitation. Before officially declaring a calendar season for monsoon, the season would be declared when there were three days at a dew point of 55º.

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.
Have sandbags ready to divert rain that may cause flash floods.
Thin trees close to your home. Many trees fall in high winds.

What Is Monsoon?

Southern Arizona, the White Mountains, and the Phoenix metropolitan area, known as “The Valley,” get the brunt of monsoon effects. It is amazing to see the haboob (desert wind storms) kick up and tower thousands of feet in the air while moving through the valley. Those storms precede the rain and massive storm cells that develop from moisture in the warm air coming off the Gulf of America. Generally, massive rainfall creates downdrafts that push air out from the storm’s center, producing a dry wind that kicks up 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 summer, the pattern shifts 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 occasional hurricanes 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 storms move through but usually don’t drop much rain here in Sedona. Though in Flagstaff, it is quite a different story! Sedona seems to be protected. By that, I mean most of the rain falls elsewhere before it reaches 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 streets slope up toward the red rocks. We’ve made major improvements to our drainage system to handle the extra water flow, but during an intense storm, there’s nowhere 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 2 inches deep. A car can be swept away quickly.

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 against 2014. Three significant hurricanes affected the weather in the southern half of the state. This caused a deluge, and many towns and neighborhoods suffered tremendous flooding damage from flash floods, hurricane winds, broken canals, and water with nowhere to go. Many long-time residents had never seen a deluge like we had that year. Sky Harbor Airport recorded 1.59 inches of rain, exceeding the all-time record set in 1903.