Arizona starts to welcome back its snowbirds, its part time residents, when autumn begins to hit. The day temperatures cool down some, allowing for comfortable evenings outside. The end of the summer brings monsoon season to Arizona. In July or August, the dew point rises briefly. The dry heat starts to carry water vapor. This hot moisture causes thunderstorms, lightening, strong winds and heavy downpours of rain. Monsoon season is the transition between the hot, dry summer months and the cooler autumn months.
Most of the moisture in the air travels from the Gulf of California and the Gulf of Mexico. The Sierra Madre Occidental is hydrated from their monsoon season, adding growing plush green forests. The evaporation from this area also adds to the moisture traveling into Arizona. If the Southern United States sees a wet early summer, it can add to the moisture coming North from Mexico. This does not bode well for a mild monsoon season in Arizona.
The rain is brief but intense. The torrential downpours can be disastrous, particularly in the higher elevations and mountains. Too much rain grows plant growth, increases summer wildfire risk. Too little rain increases drought risk. These downpours often bring more than half of the total annual precipitation.
Monsoons bring the threat of flash floods. The dry land struggles to soak the water quick enough. These flash floods cause problems to those around streams or trying to cross them. Dry washes, streams or riverbeds become dangerous instantly. There is danger in areas not being affected by the downpours as well. Flash floods can travel ten miles through these dry washes, destroying everything and everyone in its way. You do not camp, hike or play in these areas. Golf courses in Arizona often have thunderstorm warning systems to alert golfers so they are not caught in flash floods.
These monsoons are usually over mid September and average high temperatures drop about ten degrees each month, cooling to a comfortable mid 70’s high by November. This cooler weather is when gardens are planted. Fruit is ready to be harvested. There is no daylight savings in Arizona so the evenings stay light as opposed to the states that “fall back” and lose an hour of evening sun. Birds who left to find sanctuary from the hot sun begin to return.
Autumn is an incredibly beautiful time in North Central Arizona and Northern Arizona. The vibrant colors are breathtaking. Hiking becomes popular, less for the activity and more for the views. Wildlife begins to make an appearance at lakes reflecting the colors in the hillsides. The sometimes sparse foliage makes the bright oranges, yellows and reds pop out brilliantly. The crisp mornings make it prime time for hiking and sightseeing. The temperatures drop at night and overnight hikers need to pack appropriately. Jackets, sweatshirts and warm sleeping bags are necessary. Don’t get caught without being prepared for the cooler nights, dropping down into 20’s and 30’s.
The transition from summer to winter is amazing! Spend some time watching it.