Westchester's fourth area-wide blood drive of the year will take place from 8:15 a.m. to 3 p.m. Saturday, July 18, in the Mayfair Room of Divine Providence School, 2500 Mayfair Ave.

There is a critical need for donations because of a major drop in the availability of regular donors in mid-summer.

So far this year, 275 units have been collected for area hospitals by the Westchester Blood Program on its way toward its annual goal of 500 units. Last year, it collected 540 units through its six drives.

Since 1974, the organization has collected more than 21,000 units.

More information is available at (708) 865-1782.