A Flood Watch has been issued for western Pima County, the Tohono O'odham Nation and south-central Pinal County, the weather service said.
The watch is prompted by the potential for flash flooding, the National Weather Service in Tucson said Thursday.
See what today's weather forecast looks like in Tucson.
It is in effect from 1 p.m. to 8 p.m.
While there's a chance of rain in metro Tucson beginning this afternoon, the city is not included in the watch.
Scattered showers and thunderstorms are expected to produce heavy rain, with potential rainfall totals of 1 to 2 inches, and as much as 3 inches possible in mountainous areas, the weather service said of areas under the Flood Watch.
In metro Tucson, there's a 50% chance of showers later today and tonight.
Tucson is under a Flood Watch Friday and Saturday.
Photos: Star photographers pick their favorite monsoon photos
Monsoon lightning, 2021
Updated
A bolt of lightning illuminates a column of rain drenching mid-town, part of a powerful monsoon cell that dropped rain, winds and hail over parts of Tucson, Ariz., July 20, 2021.
Monsoon, 2023
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A rainbow arcs over the eastern sky behind a stand of saguaros along north Campbell Avenue, part of the scattered monsoon storm that rumbled over Tucson, Ariz., August 8, 2023.
Monsoon, 2022
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The setting sun lights up the patchy monsoon clouds overhead as Omar Rojas Jr. works on pitching out of the stretch with his dad, Omar Sr., on the diamond at David G. Herrera and Ramon Quiroz Park, Tucson, Ariz., July 21, 2022. The two Omars were working out while daughter/sister Julissa practiced nearby with her softball team. Monsoon 2022 may finally bring the rain, with precipitation forecast this weekend and throughout the coming week.
Monsoon, 2023
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Aurora Apodaca, left, lets out a laugh as she plays in the aftermath of a monsoon storm with Oscar Stump on the west side of Tucson in 2023.
Tucson weather, 2025
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Kids take a ride on playground equipment at Joaquin Murrieta Park in Tucson, Ariz. under clouds that moved in early in the evening on June 30, 2025.
Monsoon, 2014
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A woman watches the water flow down the Santa Cruz River from the Congress Street bridge on September 08, 2014. Tucson Police Department officers taped off a portion of the pedestrian/bike path along the Santa Cruz River that leads underneath Congress Street. A monsoon storm that dropped a record amount of rain on Monday. The closing of the path was a precaution due to the risk of the rising water.
Rainy day in Tucson, 2023
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Scott Saas listens to music while rain showers continue throughout Southern Arizona, E. University Blvd, Dec. 1, 2023. Tucson is predicted to get anywhere from 1 to 3 inches of rain Friday.
Monsoon clouds, 2025
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The "Balancing Act” sculpture poses underneath the dark cloudy skies as rain showers pass through Southern Arizona, 4502 North First Avenue, Tucson, Ariz., July 2, 2025.
Monsoon, 2025
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A truck drives through flooded streets as heavy rain showers hit the city of Tucson, West Fort Lowell Road, Tucson, Ariz., July 3, 2025.
