The weather at Grasslands National Park is characteristic of south-west Saskatchewan. Hot summers, cold winters, winds, and low precipitation are normal for this semi-arid area. Precipitation averages only 30-33 cm per year. Half of the moisture falls during the summer, mainly in June and July through erratic thunderstorms. A third of the moisture falls as snow.
Summers see very high daytime temperatures averaging mid-high 20s °C and often in the 30s °C. Rapidly changing weather conditions are common, especially late afternoon thunder and lightning in summer. Severe winds are dangerous, and finding shelter can be difficult. Evenings cool down into the high teens-low 20s °C. Hot summer days are characterised by late afternoon thunder and lightning storms. Early and late summer are the most pleasant time to visit the area, as temperatures are more moderate.
Little rain falls in the area of the park - usually in the form of short-lived showers. But when it does arrive in any quantity, park roads may become impassable when wet.
Cooler spring and fall temperatures make these the times to walk and explore the park. In addition, flowers are abundant in late May and early June. Also, these are the seasons when migratory wildlife are moving. Early spring is also a time of 'May showers'.
Fall and early winter (October - November) start to see a transition to cooler temperatures, ranging from the mid-teens to just below freezing. The first storms of winter generally begin in November, and cold weather continues until February. Snowfall is minimal, so winter activities can include hiking, but rarely cross-country skiing. Warmer days arrive towards the end of February.
Wind is a part of the landscape at Grasslands, and as Wallace Stegner says, "you learn to live with it, as part of it."