Based on the meteorological data (from 1971-2000) originating from 9 weather stations in the north-eastern region of Poland, the following information was determined: no-morning frost period, number of days with morning frost falling into the following temperature groups: 0 do -2oC; -2.1 to -4oC; -4.1 to -6oC and below -6oC, and occurrence of sequences of days with morning frost grouped into 2, 3, 4 and > 4-day sequences. The occurrence of the above values was measured during vegetation periods at the height of 5 and 200 cm. The no-morning frost period determined at the height of 2 m ranged from 143 days in Gołdap to 173 days in Mikołajki, while this value measured at the height of 5 cm ranged from 112 days in Suwałki to 145 days in Mikołajki. The morning frosts ranging from 0 to -2.0oC were the most frequent.