Saskatchewan is a prairie province situated at the top of the Northern Great Plains between Manitoba and Alberta, and above North Dakota and Montana. The climate is semi-arid, with a five month cold winter (extreme temperature of -47 °C) and relatively warm dry continental summer (extreme temperature of 42 °C), low annual precipitation (range from 370 to 420 mm) with the majority of rainfall (265 to 320 mm) received in April to August in the cropping regions. The pulse crops pea and lentil, and the oil crop canola are increasing in the rotations of what traditionally was cereal-based agriculture. Historic weather records were analyzed for trends in warming, cooling and drought, with an overall result of an average temperature increase of 1.7 °C in the last century. Recent historic yield records for spring wheat, canola, lentil and pea were also examined for representative production areas to demonstrate fluctuations linked to agronomic and climatic factors. Finally, crop yield was described as a function of various weather parameters using multiple regression modeling, with the aim of identifying important climatic factors associated with yield variability. Wheat yield was greatly influenced by average seasonal maximum and minimum temperature, and annual rainfall. For canola, minimum temperature played a greater role along with seasonal rainfall, and weather specific to June, July and August. For lentil, a highly indeterminate crop, yield was influenced strongly by maximum June to August temperature, rainfall and annual precipitation (rain and snow).