Climate of Minnesota

Minnesota's location in the Upper Midwest allows it to experience some of the widest variety of weather in the United States, with each of the four seasons having its own distinct characteristics.

The moderating effect of Lake Superior keeps the surrounding area relatively cooler in the summer and warmer in the winter, giving that region a smaller yearly temperature variation.

Snowstorms are common early in the spring, but by late-spring as temperatures begin to moderate, the state can experience tornado outbreaks, a risk which diminishes but does not cease through the summer and into the autumn.

The state is nearly 500 miles (805 km) from any large body of water (with the exception of Lake Superior), and temperatures and precipitation vary widely.

The lake acts as a heat sink, keeping the state's North Shore area relatively cooler in the summer and warmer in the winter.

A vigorous jet stream brings high and low-pressure systems through in quick succession, which can cause large temperature variations over a short period of time.

[33] High pressure systems which descend south from the Canadian plains behind the fronts bring light winds, clear skies, and bitterly cold temperatures.

This means that the jet stream will move in a west to east motion—rather than north to south—and warmer air from the western United States is pushed into the region.

[36] This pattern becomes especially common when El Niño is present, as the jet stream is weakened and pushed further north into Canada, therefore arctic air is often blocked from entering Minnesota.

Because of the limited moisture content and quick movement of the systems, clippers rarely produce more than 6 inches or 0.15 metres of snow as they pass through Minnesota.

[43] As these systems move to the northeast, there will usually be a heavy band of snow to the northwest of the low pressure center if there is enough cold air present.

[44] Snowfall of over a foot (30 cm) is not uncommon with a panhandle hook, and because of the high moisture content in these systems the snow is usually wet and heavy.

Large panhandle hooks can become powerful enough to draw in arctic air after they pass by the state, leaving bitter cold temperatures and wind chills in their wake.

In the early part of the spring, Minnesota is usually not in a geographically favorable position to experience severe weather since the warm air needed for it has not yet pushed that far to the north.

More often, Minnesota is on the northern (cooler) side of major storm systems in the early spring, which instead results in only rain and possibly snow.

[47] As spring progresses, the jet stream starts to push storm systems farther to the north, and southern Minnesota becomes more prone to severe thunderstorms and tornadoes.

With the exception of areas along the shores of Lake Superior, winds in Minnesota generally prevail from the north and northwest in the winter, and south and southeast in the summer.

The heaviest winds in the state are found on the Buffalo Ridge, or Coteau des Prairies, a flatiron-shaped area extending from Watertown, South Dakota, diagonally across southwestern Minnesota and into Iowa.

A main feature of summer weather in Minnesota and the Midwestern United States as a whole is the weakening of the jet stream, leading to slower movement of air masses, a general increase in the stability of temperatures, and less wind.

[13] Because summer time air masses are not as volatile as in the winter, daily high and low temperatures rarely vary more than 15 degrees (7 °C) either side of normal.

Coteau des Prairies can heat cities to the north of it similar to how places in the Rocky Mountains are warmed by Chinook winds.

[7] The summer months of June, July, August, and September account for nearly half of the annual precipitation total across the state of Minnesota.

The combination of dry skies and heat caused a severe drought which cost the state approximately 1.2 billion dollars in crop losses.

With summer-time heat still prevalent in the southern U.S. and colder air quickly taking hold in Canada, Minnesota can be affected by wide temperature swings in short periods of time.

[70][71] As autumn moves on, these storm systems bring with them progressively colder air, eventually changing the rain over snow, generally starting in October in the northern part of the state and November in the south.

Rising temperatures may interfere with winter recreation, extend the growing season, change the composition of trees in the North Woods, and increase water pollution problems in lakes and rivers.

Water skiing was invented in Minnesota by Ralph Samuelson, and the Minneapolis Aquatennial features a milk carton boat race.

Contestants build boats from milk cartons and float them on Minneapolis area lakes, with recognition based more on colorful and imaginative designs than on actual racing performance.

The state has produced curlers, skiers, and lugers who have competed in the Winter Olympics, pioneers who invented the snowmobile, and legions of ice fishing enthusiasts.

A World War II newscaster, in describing the brutally cold conditions of the Russian front, stated that at least Minnesotans could understand it.