Contacts: Molly Woloszyn (mollyw@illinois.edu)

 Samantha Borisoff (samantha.borisoff@cornell.edu)

Great Lakes Region Quarterly Climate Impacts and Outlook / Sept. 2013 (Experimental)

www.drought.gov/drought/content/resources/reports

Quarterly Climate Impacts 

and Outlook

Great Lakes Region

Sept. 2013 (Experimental)

 Great Lakes Significant Events - for June - August 2013

Precipitation and Temperature Great Lakes Water Levels

Regional Climate Overview - for June - August 2013

Summer conditions generally helped maintain the 

water level rise in each of the lakes due to the wet 

spring with all the lakes above their levels from 

this time last year and all above their chart datum’s 

over the summer. Nevertheless, water levels of 

Lake Michigan-Huron remained well below the 

long-term average. 

On July 8th, 126.6 mm (5 in.) of rain fell in the 

Toronto region in just a few hours, causing severe 

flash flooding in the city and other issues like widespread power outages and major transportation 

problems. This precipitation, which for this region 

was more than the average monthly total for July, 

broke the all-time record for heaviest 1-day precipitation in Toronto. 

Parts of the Midwest were abnormally dry in August. In the Great Lakes basin, Illinois experienced 

its 3rd driest August, while Indiana experienced its 

4th driest and Minnesota its 7th driest.

August was a month of extremes for Minnesota 

in terms of temperature. The month kicked off with much cooler than normal temperatures across the state and early season freeze warnings as well as the first 0°C (32°F) freeze reports of the fall season. As the month went on, it warmed up drastically and August ended with a 

late-season heat wave across the state. Duluth, Minnesota experienced 14 consecut﻿ive days of temperatures above 26.6°C (80°F) from August 

15th-28th, three of which were days over 32°C (90°F). Temperatures over 32°C (90°F) do not occur very frequently in Duluth, even in August.

Water levels on all the lakes except Superior 

reached seasonal peaks between June and 

August. From winter low to summer high, all 

lakes had an above-average seasonal rise. 

While Lake Superior’s August mean level 

was 9 cm (3.5 in.) below average, it was at 

its highest August level since 1999. Lake 

Michigan-Huron’s August mean level was 47 

cm (18.5 in.) below average, but 11 cm (4.3 

in.) higher than it was at the same time in 

2012. August water levels on Lakes Erie and 

Ontario were above long-term average at +3 

cm (1.2 in.) and +11 cm (4.3 in.).

During summer, the U.S. Great Lakes basin 

received 301.24 mm (11.86 in.) of rain, 108% 

of normal. Of 25 climate divisions, 14 were 

wetter than normal, with North Central 

Ohio having its wettest summer on record 

at 153% of normal. The driest division, 

northeast lower Michigan, received 68% of 

normal. The Canadian side received abovenormal summer precipitation overall, but 

it was not evenly distributed. Most regions 

were abnormally wet in July, but drier in 

August. For instance, north of Lake Erie saw 

150-200% of normal July rainfall, but only 

40-60% in August. 

The average summer temperature of 19.3°C 

(66.8°F) in the U.S. Great Lakes basin was 

0.1°C (0.2°F) cooler than normal. Seventeen 

of the 25 divisions were cooler than normal 

with departures ranging -1.0°C (-1.8°F) in 

northwest Indiana to +0.6°C (+1.0°F) in 

northeast Minnesota. The Canadian side of 

the Great Lakes basin experienced nearnormal temperatures during summer with 

record heat and humidity near the end of July.

Normals based on 1981-2010.

Precip: Canada/Great Lakes data based on 

Canadian Precipitation Analysis. U.S. data based on 

interpolated station data.

Water level statistics based on 1918-2012.

June 1-August 31, 2013 June 1-August 31,2013

South Haven, MI - June 27, 2013

Photo: Michigan Sea Grant

Precipitation: Percent of Normal (%) Temperature: Departure from Normal (deg)
Regional Impacts - for June - August 2013

Regional Outlook - for Fall 2013 Great Lakes Region Partners

Environment Canada

www.ec.gc.ca

Agriculture and Agri-Food Canada

www.agr.gc.ca 

Midwestern Regional Climate Center

www.mrcc.isws.illinois.edu

Northeast Regional Climate Center

www.nrcc.cornell.edu

Great Lakes Region State Climatologists

www.stateclimate.org

National Oceanic and Atmospheric Administration

www.noaa.gov

National Climatic Data Center

www.ncdc.noaa.gov

National Ocean Service

www.oceanservice.noaa.gov

National Operational Hydrologic Remote Sensing Center

www.nohrsc.nws.gov

Great Lakes Environmental Research Laboratory

www.glerl.noaa.gov

NOAA Great Lakes Sea Grant Network 

www.seagrant.noaa.gov

North Central River Forecast Center

www.crh.noaa.gov/ncrfc

NOAA’s Great Lakes Regional Collaboration Teams

www.regions.noaa.gov

Climate Prediction Center

www.cpc.noaa.gov

Great Lakes Integrated Sciences & Assessments

www.glisa.umich.edu

US Army Corps of Engineers

www.usace.army.mil

National Integrated Drought Information System 

www.drought.gov

Great Lakes Water Level Dashboard

www.glerl.noaa.gov/data/now/wlevels/dbd/

United States Department of Agriculture

www.usda.gov

Ontario Tourism

www.ontariotravel.net

#regionalclimateoutlooks

Contacts: Molly Woloszyn (mollyw@illinois.edu)

 Samantha Borisoff (samantha.borisoff@cornell.edu)

Great Lakes Region Quarterly Climate Impacts and Outlook / Sept. 2013 (Experimental)

 www.drought.gov/drought/content/resources/reports

In the northern 

Great Lakes, 

normal peak 

color time is 

typically late 

September 

through early 

October. In the 

southern Great 

Lakes, normal 

peak color time is later, typically in midOctober. This year, peak dates and intensity 

of fall color in the western Great Lakes may 

be affected slightly by the late summer 

drought that developed in this region.

Agriculture

Abnormal spring weather 

in 2012 devastated 90% 

of Michigan’s apple crop, 

yielding just 2.7 million 

bushels last year. This year, 

thanks to perfect growing 

conditions, Michigan apples 

are back. The Michigan Apple 

Committee estimates that the 

state’s apple crop will be 30 million bushels in 2013, which is about 10 

million bushels above average. The Apple Committee said a crop like 

this could pump as much as $900 million into the state’s economy. 

Water Quality

Sources of phosphorus runoff are to 

blame for a rash of harmful algal blooms 

on Lake Erie that developed in July. The 

International Joint Commission said in 

a draft report that urgent steps need to 

be taken by the U.S. and Canada to curb 

runaway algae, which produce harmful 

toxins and contribute to oxygen-deprived 

“dead zones” where fish cannot survive. 

Climate change and heavier rains, leading to increased runoff, could 

increase the occurrence of algal blooms in the future. 

Infrastructure & Transportation

The July 8th flooding event 

in Toronto caused $850 

million worth of damage 

in this area, making it the 

most expensive insurance 

event in Ontario’s history. Residential flooding was a major issue, 

but infrastructure and transportation issues were also widespread. 

Infrastructure and transportation issues included damage to hydroelectric power plants, widespread power outages, and flooded 

subway stations and streets, making a horrific and dangerous evening 

commute the day of the event. 

Shipping

Shipping on the U.S. Great Lakes is suffering as a result of low water 

levels. Typically, the Great Lakes shipping sector transports more than 

160 million tons of cargo each year, resulting in a $34 billion industry. 

However, when water levels are low, shippers cannot load their 

vessels with as much cargo. The aggregate impact over time will be 

to raise the cost of commodities, which in turn will raise the price of 

manufacturing goods and price to the consumer. 

Lake Level Outlook 

Temperature & 

Precipitation Outlook

Current projections for the fall months 

indiciate that Lake Superior and Lake 

Michigan-Huron will remain below average, 

although it is very unlikely water levels will 

fall to record low levels seen last fall and 

winter. On the other hand, a wet fall could 

see levels on Lake Superior slightly above 

average. A prolonged period of above-average 

water supplies will be required to return the 

water levels of Lake Michigan-Huron to their 

long-term averages. Lakes Erie and Ontario 

are expected to remain near their long-term 

averages through the next quarter. 

The Climate Prediction Center and 

Environment Canada are both forecasting 

equal chances for above, below, or near 

normal precipitation in their respective 

basins throughout October, November, 

and December. For the same time period, 

the temperature outlook from the Climate 

Prediction Center is calling for equal chances 

of above, below, or near normal temperatures 

in the U.S. basin, while Environment Canada is 

forecasting greater chances for temperatures 

to be slightly above normal in the Canadian 

basin. 

Outlook from the US Army Corps of Engineers 

and Environment Canada (Fall 2013) 

Above: algal bloom on August 16th; Photo courtesy of 

OH Sea Grant & Jeff Reutter

Left: commuters were stranded 

for more than three hours on 

a GO Train; Photo courtesy of 

CBC News

Fall Foliage

Above: Ottawa National Forest; 

Photo courtesy of USDA