Typically, Tucson will receive its first monsoon rainfall near July 3 — almost three weeks after the season's official start date, which is this Friday, June 15. So, what's the rush?

The National Weather Service, Tucson Weather Forecast Office gives two reasons for declaring specific start and end dates for monsoon in Arizona and New Mexico: One, this allows forecasters to gather and analyze data for the same days each year. Any patterns or trends can be easily identified and tracked from year-to-year.

Two, the early start gives the National Weather Service time to inform residents of these areas about the possible adverse conditions that can occur during the summer rainy season, which is when flash floods, thunderstorms, lightning, wildfires, dust storms and extreme heat are concerns. That information is being distributed this week as part of Monsoon Safety Awareness Week.

Through Friday, the NWS Tucson Office is posting online presentations that explain these weather phenomenon. Sunday's presentation, "An introduction to monsoon," can be seen here. Today's topic on the site is lightning.

Learn more from the experts

A group of local safety organizations — including Tucson Electric Power, VAISALA, the American Red Cross, U.S. Forest Service, Pima County Regional Flood Control District, Southern Arizona Rescue Association, and fire departments from throughout the area — will be part of a safety fair from 10 a.m. to 2 p.m. Thursday at Park Place mall.

Ask your monsoon questions

At noon Wednesday, the Arizona Daily Star will host a live, online chat with JJ Brost and Ken Drozd of the NWS Tucson Office. Submit your summer weather questions for them now.

Have a weather question or a weather story idea? Send it to the Arizona Daily Star's "Thunderstruck" reporter Kori Rumore at krumore@azstarnet.com.