What is the average precipitation in illinois

Low Annual Rainfall US Avg: Annual Snowfall US Avg: 25". Precipitation Days US Avg: Sunny Days US Avg: Select Map Options. Reviews for Illinois 77 Reviews. Read More. Agree 0 Disagree 0. Agree 10 Disagree Rent keeps on going up because of all the tax increases every Agree 25 Disagree Try Now. All rights reserved. Within Illinois and the Midwest, flood losses have been increasing at a greater rate than elsewhere in the nation.

Five factors control the continental climate of Illinois: 1 the sun, 2 weather systems, 3 topography, 4 urban areas, and 5 Lake Michigan. Two major controls are latitude reflecting the amount of solar input and weather systems air masses and cyclonic storms.

The effects of topography, Lake Michigan, and urban areas are of lesser significance because they influence local climate conditions, rather than conditions statewide. The sun, primary energy source for virtually all weather phenomena, in large part determines air temperatures and seasonal variations. The polar jet stream often is located near or over Illinois, especially in fall, winter, and spring, and is the focal point for the creation and movement of low-pressure storm systems characterized by clouds, winds, and precipitation.

The settled weather associated with high pressure systems is generally ended every few days by the passage of low-pressure systems. Topography, urban areas, and Lake Michigan are the three local influences with effects on Illinois climate. The Shawnee Hills extend across southern Illinois and have elevations to feet higher than the surrounding terrain. This change in elevation is enough to increase annual precipitation by about 10 to 15 percent.

The second local feature is the urban climate found in many cities. Buildings, parking lots, roads, and industrial activities make the urban climate noticeably different than that of surrounding rural areas. Urban areas also enhance summertime precipitation downwind of the city and cause changes in humidity, cloudiness, wind speeds and directions. Lake Michigan influences the climate of northeastern Illinois, especially Chicago.

The large thermal mass of the lake tends to moderate temperatures, causing cooler summers and warmer winters. One of the major benefits is cool lake breezes that provide some relief from summer heat.

The lake also tends to increase cloudiness in the area and suppress summer precipitation. Winter precipitation is enhanced by lake-effect snows that occur when winds blow from the north or northeast.

These winds allow air to pass over the relatively warm lake, boosting storm system energy and water content, and leading to increased snowfall. Average winter highs range from the 30s north to the mids south , while average lows range from the teens north to the upper 20s south. Average summer highs are in the 80s, while lows are in the 60s across the state. Both spring and fall have more moderate temperatures. Average annual heating-degree days range from days north to days south.

Average annual cooling-degree days range from days north to days south. The average length of the frost-free growing season in Illinois ranges from days north to more than days south. Thus, future summer droughts, a natural part of the Illinois climate, are likely to be more intense. Kunkel, K. Stevens, S. Stevens, L. Sun, E. Janssen, D. Wuebbles, S. Hilberg, M.

Timlin, L. Stoecker, N. Westcott, and J. National Climate Assessment. Part 3. Climate of the Midwest U. Woloszyn, and J. Drought Monitor Map Archive, cited U. Easterling, K. Kunkel, A. LeGrande, and M. Wehner, Temperature changes in the United States. Fahey, K. Hibbard, D. Dokken, B. Stewart, and T. Maycock eds. Winters, B. Angel, C. Ballerine, J. Byard, A. Flegel, D. Gambill, E. Jenkins, S. McConkey, M. Markus, B. Bender, and M. Key Message 2 Precipitation in spring and summer has generally been above average over the past two decades, affecting agriculture in both positive adequate soil moisture and negative delays in spring planting ways.

Key Message 3 Severe flooding and drought have occurred periodically in recent years. Figure 1: Observed and projected changes compared to the — average in near-surface air temperature for Illinois.

Observed data are for — Projected changes for — are from global climate models for two possible futures: one in which greenhouse gas emissions continue to increase higher emissions and another in which greenhouse gas emissions increase at a slower rate lower emissions. Shading indicates the range of annual temperatures from the set of models.

Observed temperatures are generally within the envelope of model simulations of the historical period gray shading. Historically unprecedented warming is projected during the 21st century,.