The average humidity is 83% in the year, some months of the year with average humidity of 85%. The dry season the air humidity ranges between 74% - 80%.

The average rainfall is about 1,533 mm annual, rainfall much during these months from April to September. Annual average evaporation about 1,000 mm, 4 months have evaporation greater than rainfall is from December of previous year to March of next year.

Wind regime basically influenced by wind Southeast (summer) and northeast winds (winter). Some high mountainous area morphologically cold dry weather, cold weather, frost in winter. Less Laos wind appeared in the summer. Some mountainous districts have a local phenomenon tornado, hail, floods in the rainy season. Bac Giang less affected by the storm due to the shielding of high mountains.

The annual average sunshine from 1500-1700 hours, convenient for cultivation and development of tropical plants, tropical. /.