Fall is finally approaching in Arizona as residents look forward to cooler days in the upcoming month.
While Arizona has not seen much of a cool down from the intense summer heat yet, the season change is right around the bend, and the National Weather Service, AccuWeather and The Old Farmer's Almanac have all released their long-term predictions for the fall season.
All the weather groups have slightly different predictions for the upcoming season; each forecast uses different methodologies for its reporting. Still, all of the three are regarded as trusted forecasters.
When does fall start?
The first day of fall, also known as the fall equinox, is Tuesday, Sept. 22, 2026.
What will the weather be like in Arizona this fall?
The National Weather
Service and The Old Farmer's Almanac both agree that Arizona will see a slightly warmer-than-usual fall season, but AccuWeather disagrees.
According to the National Weather Service, Arizona has a 33% to 40% probability of above average temperatures. This is the same across the whole state.
The Old Farmer's Almanac agreed that Arizona will have a warmer-than-average September to start the fall season, but temperatures were expected to cool slightly in October.
AccuWeather reported that parts of Arizona were expected to be one to two degrees below historical levels from September to October, while southern Arizona cities like Sierra Vista and Nogales were expected to see temperatures remain at historical averages.
Will it rain this fall?
The National Weather Service and AccuWeather both predicted that Arizona will see above-average precipitation levels in the fall season, while The Old Farmer's Almanac predicted that most of the state will have a drier-than-usual season.
According to the National Weather Service, Arizona had a 40% to 50% probability of above-average rainfall this fall season, across nearly the whole state, while AccuWeather predicts Arizona will see even more rain.
According to AccuWeather, storms were expected to continue throughout the fall in Arizona. AccuWeather maps show extreme weather was expected most in September, slowing down at the end of fall.
During this peak severe weather period in September, all of Arizona could expect high precipitation levels of 125% to 149% above normal.
However, the Old Farmer's Almanac predicted that Arizona will have a drier-than-usual fall, with rainfall remaining below average. However, the northern-central area of the state, from Sedona heading north, was expected to have a warm and wet fall, with precipitation levels higher than the rest of the state.
How does each weather group make its prediction
While each weather group varied in its prediction for the upcoming fall season, they also each have their own methodology for their forecasts.
According to the National Weather Service, forecasts are made using several airborne and ground-based satellites to track weather patterns. Then forecasters use computer programs and numerical, conceptual and statistical models to determine how conditions will change over time.
Similarly, AccuWeather uses databases around the world to collect weather forecasts in real time, then digitally processes the data to collect trends of weather happening in certain areas historically, according to the company.
The Old Farmer's Almanac's current weather forecasting method is a modern adaptation of a formula developed by the almanac's founder, Robert B. Thomas, in 1792. The Almanac specializes in extended weather predictions to help farmers plan their crops for the season using a method influenced by sunspots, which are magnetic storms on the surface of the sun.
This article originally appeared on Arizona Republic: Will Arizona finally cool down this fall? Here's the outlook
