Nemunas Delta Regional Park territory belongs to the Seaside lowlands climatic sub-district.
The average temperature of the Nemunas River Delta: in January - 5,7 ° C, in April - +5.0 ° C, in July - +17 ° C, in October - +7.0 .. . +7.5 ° C. The minimum temperature in winter: - 23 ° C (average), -35 ° C (maximum). First autumn frosts of the soil surface begins on about 10 October. Soil frosts up to 80 cm depth. Frost period lasts from December 15 to April 3. Constant snow cover is formed from December 25 to 30 days and a maximum thickness snow cover on average 10-15 cm (deeper winters - 30-35 cm). During the year usually there are 75-80 days with snow cover.
The average annual rainfall in the park from 700 to 750 mm per year. Most rain falls in September: 75-85 mm, the lowest in March - 35-40 mm.