* WHAT...Overnight temperatures of 30 to 37 degrees will result in frost formation in wind sheltered valleys in the eastern portions of the Inland Empire and San Diego County.

* WHERE...San Bernardino and Riverside County Valleys-The Inland Empire and San Diego County Valleys.

* WHEN...From 10 PM this evening to 9 AM PST Sunday.

* IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered.