In 2008 the National Weather Service decided to declare a monsoon season from June 15 to Sept. 30. The change, at least in part, allows the Weather Service an opportunity to consistently promote its safety messages connected to the monsoon.
The word “monsoon” is derived from the Arabic word “mausim,” which means season. It doesn't refer to individual storms, but to a season.
The monsoon is essentially a change in the weather pattern. Dry winds that typically blow from the west and southwest tend to shift to the south and southeast, bringing up moisture from the Gulf of California.
That moisture, coupled with the heat of summer, fuels the storms.
Through 2007, the start of the monsoon was determined by three consecutive days of average dewpoint temperatures of 55 degrees or higher.
We can’t do anything to prevent the monsoon, but we can prepare.
Sandbags are the best way to divert water from doorways and help to protect your home from flooding during a monsoon storm..
Read the City of Tucson's "Flood and Erosion Hazard Protection" for more information that provides valuable tips should a summer monsoon turn into a more serious flooding situation.
Flood waters on the roads
According to the National Weather Service, nearly half of all flood fatalities are vehicle-related.
Never drive into a flooded roadway. It is extremely difficult to estimate the depth of running water or the strength of a current.
Never drive around barricades. They are there for a reason, usually because flooding is anticipated or has already happened. In addition, the road could be damaged and unsafe for drivers.
Never allow children to play around floodwaters or washes. They can be swept away.
It only takes 1 to 2 feet of water to float most vehicles, including SUVs.
If you can hear thunder, then you are close enough to be struck by lightning.
Take shelter in a sturdy building or a hard-topped vehicle. You should remain in this shelter 30 minutes after hearing the last rumble of thunder.
Telephone lines conduct electricity, so avoid using landline phones during a storm.
Metal pipes also conduct electricity, so avoid taking showers and baths or using running water during a storm.
Bring pets indoors.
Arizona thunderstorm winds often exceed 40 mph and straight-line winds can exceed 100 mph.
Move into a central interior room away from windows to avoid blowing debris that could shatter glass.
If you are driving in high winds, slow down and anticipate steering correction when moving from protected to unprotected wind areas or when encountering large passing vehicles.
Be aware of high-profile vehicles — trucks, semis, buses, campers, or those towing a trailer — because they can be unpredictable during high winds.
Before the monsoon storm hits, evaluate large trees close to your home for potential hazards.
If you are caught in a dust storm while driving, pull off the roadway as far as safely possible. Turn off headlights and taillights, put the vehicle in park, and take your foot off the brake.
With reduced visibility, other drivers behind you could see the brake lights and assume you are driving on the road and follow your lights.
When severe dust storms occur, consider cleaning your smoke detectors. Dust can clog detectors and cause false alarms.
Downed power lines
Across a roadway:
Consider any downed power line to be energized and dangerous. Never touch a downed power line or anything close to it. High voltage can travel through the ground. Stay at least 100 feet away from any downed lines.
Across a vehicle:
If the vehicle is occupied, stay in the vehicle until professional help arrives. Avoid contact with metal surfaces both inside and outside the vehicle. If there is a fire in the vehicle, jump from the vehicle landing on both feet. Hop away, keeping both feet in contact with each other until you are at least 100 feet from the vehicle.