Deniliquin experiences a semi-arid environment with hot dry summers and cool winters. The frost-free period is normally October to April. Winds are strongest October to November and storm activity is more likely in December. Average annual rainfall is approximately 400mm with most reliable falls occurring from May to October. Inputs from rainfall only account for approximately 20% of average annual evapotranspiration (1800 mm). Profitable production of dryland winter crops occurs in most years but summer crops must be irrigated.

Monthly averages for maximum and minimum temperatures and rainfall (1971-2000)