Quarterly Climate Impacts 

and Outlook

Great Lakes Region

June 2015

#regionalclimateoutlooks

Great Lakes Region 

Quarterly Climate Impacts and Outlook

 - June 2015 - 

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

www.ec.gc.ca/eau-water/default.asp?lang=En&n=F5329B03-1

 Great Lakes Significant Events - for March - May 2015

Precipitation

Regional Climate Overview - for March - May 2015

Overall, the Great Lakes basin experienced dry and cool 

conditions during spring 2015. The dryness was most 

prominent in March and April and drought conditions 

spread throughout the basin. However, May did bring 

some precipitation and drought relief to most areas in 

the basin.

Water supplies in the Lake Ontario basin in March were 

near record lows for the second straight month, delaying 

the typical seasonal lake level rise. In combination with 

the generally dry conditions that followed, Lake Ontario 

experienced well below average water levels in April and 

May and by the end of May was 18 cm (7.1 in) below 

average - the lowest it’s been since 2010. Water supplies 

were closer to normal on lakes Superior, MichiganHuron, and Erie over the quarter, and water levels 

continue to remain above average for those lakes. 

The last two winters (2013/14 and 2014/15) were 

the first time since the 1970s there has been two 

consecutive years where at least three of the Great Lakes 

were more than 95% ice covered. Also, ice was present late into the season on some lakes. Ice cover on Lake Superior lingered until May 28, 

which is only the 4th time in the 40 year period of record that ice cover has remained on Lake Superior through late May. 

A strong low pressure system brought unseasonably cold temperatures into the basin from May 19-23. Some locations across Ontario, 

northern Minnesota, Wisconsin, and Michigan experienced freezing temperatures - some as low as -5.5°C (22°F) - resulting in significant 

vegetation damage in some areas. Just days prior, this same system brought freezing precipitation and snow to areas in Ontario. While 

snowfall totals were not substantial, some areas reported several hours of freezing precipitation during this late season winterlike storm. 

Spring transitioned from a cold March to a near normal April to a 

mild May. March temperatures were up to 4°C (7.2°F) colder than 

normal, except in the western Lake Superior basin (see left figure). 

April temperatures were within 2°C (3.6°F) of normal in the entire 

basin. May temperatures were up to 4°C (7.2°F) warmer than 

normal, except in the northern Lake Superior basin (see right figure). 

Overall, spring temperatures were up to 2°C (3.6°F) colder than 

normal in the northern basins of lakes Superior and Michigan-Huron 

and near normal in the rest of the basin.

Water level statistics based on 1918-2014. 

May 2015 Temp: Dep. from Normal

Air Temperature

Great Lakes Water Levels

Water levels usually rise during spring as precipitation and runoff 

increase, and evaporation rates are low this time of year. After a cool 

and dry start in March, this spring brought normal to slightly wetter 

than normal conditions for the Great Lakes region, with the exception 

of Lake Ontario, where basin conditions were mostly dry. Lake Superior 

finished the quarter 19 cm (7.5 in) above the long-term average and 5 

cm (2.0 in) higher than last year, while Lake Michigan-Huron finished 

the quarter 14 cm (5.5 in) above average and 31 cm (12.2 in) higher 

than last year. Lake Erie water levels were 12 cm (4.7 in) above average 

and 4 cm (1.6 in) higher than last year. The dry conditions contributed 

to Lake Ontario ending the quarter 18 cm (7.1 in) below average and 31 

cm (12.2 in) lower than the last year at this time.

March and April were drier 

than average for all lake basins. 

Overall, the Great Lakes basin 

saw 44% of average March 

precipitation and 90% of average 

April precipitation. All lake basins 

but Ontario were wetter than 

average in May, with the overall 

basin seeing 115% of average. 

Spring was drier than average for 

all lake basins, with the overall 

basin seeing 87% of normal. 

Precipitation normals based on 1981-2010.

March and May 2015 graphics are shown to display the range in temperatures this 

spring. Temperature normals based on 1981-2010.

March 2015 Precipitation: 

Percent of Normal (%)

March 2015 Temp: Dep. from Normal
Regional Impacts - for March - May 2015

Regional Outlook - for July - September 2015 Great Lakes Region Partners

Environment Canada

www.ec.gc.ca

Agriculture and Agri-Food Canada

www.agr.gc.ca 

Midwestern Regional Climate Center

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 Operational Hydrologic Remote Sensing Center

www.nohrsc.noaa.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

Ohio River Forecast Center

www.weather.gov/ohrfc 

Climate Prediction Center

www.cpc.noaa.gov

Great Lakes Integrated Sciences & Assessments

www.glisa.umich.edu

US Army Corps of Engineers, Detroit District

www.lre.usace.army.mil

National Integrated Drought Information System 

www.drought.gov

Great Lakes Water Level Dashboard

www.glerl.noaa.gov/data/dashboard/GLHCD.html

#regionalclimateoutlooks

Contact for NOAA: 

Molly Woloszyn: mollyw@illinois.edu

Samantha Borisoff: samantha.borisoff@cornell.edu

Contact for Environment Canada: 

greatlakes-grandslacs@ec.gc.ca

enviroinfo@ec.gc.ca

Great Lakes Region 

Quarterly Climate Impacts and Outlook

 - June 2015 - 

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

www.ec.gc.ca/eau-water/default.asp?lang=En&n=F5329B03-1

Contact Information

Environment Canada (EC) is forecasting a greater chance for above normal temperatures in 

the Canadian basin for July-September, while the Climate Prediction Center (CPC) says there is 

no clear signal whether temperatures will be above, near, or below normal in the U.S. basin. 

The July-September forecasts from EC and CPC show no clear signal for precipitation as well.

For July, CPC says there is no clear signal across a majority of the U.S. basin in terms of 

temperature or precipitation, but they are calling for a greater chance for above normal 

preciptiation near southern Lake Michigan. For the Canadian basin, EC is calling for above 

normal temperatures in the east and near normal in the western Canadian basin. EC says there 

is no clear signal for July precipitation in the Canadian basin. Current outlooks can be found 

through the Climate Prediction Center and Environment Canada.

Shipping

The opening of the Lake Ontario to 

Montreal section of the St. Lawrence 

Seaway was delayed until April 2 due 

to extensive ice cover, completing the 

full Seaway opening about one week 

later than normal and the latest since 

1997. In fact, despite the locks on the 

St. Marys River opening on March 25 as 

planned, the navigation season generally 

started slowly across the Great Lakes 

region, and for the second straight year 

the shipping industry relied heavily on the U.S. and Canadian Coast 

Guards to clear shipping lanes of ice early in the season. The most 

notable example occurred during the first week of April, when a clog 

of vessels sat for days in Whitefish Bay in eastern Lake Superior until 

a heavy ice-breaker from Montreal arrived to help clear pathways 

through a large ice field. 

Industry

The extensive ice cover on the Great Lakes delayed the commercial 

fishing season - a $100 million industry for the Great Lakes - by a few 

weeks this March for the second year in a row. Ideally, the boats like to 

be out in early March to keep up with the fish demand during Lent but 

were delayed this year until the end of March.

Agriculture

Freeze events from May 19-23 caused significant crop damage 

in Michigan, particularly across the northwest portions of Lower 

Michigan where temperatures fell as low as -5°C (23°F). The most 

severe damage occurred to vinifera grapes, with some growers 

reporting no remaining live shoots. This is the second consecutive 

season grape growers in this region had major crop losses. Other crops 

with significant damage in Michigan were blueberries, sweet and tart 

cherries, peaches, and apples. Minor damage was also reported in 

Ontario to vinifera grapes, corn, soybeans, and strawberries.

While the dry spring conditions were favorable for spring planting 

operations, the overall dry conditions throughout much of the spring 

could negatively impact crop germination and plant growth in crops. 

Wildfires

The dry conditions extending from 

winter into spring produced an active 

fire season over portions of the basin 

the last three months, especially over 

Minnesota and Lower Michigan. The 

largest fire in Minnesota was the Palsburg 

Fire, which began on April 15 and burned 

approximately 6,000 acres primarily in 

Beltrami Island State Forest. Smaller fires in Minnesota resulted in 

evacuations of nearby homes, businesses, and schools. 

Lake Level Outlook

Water levels typically peak in the summer months 

before beginning to decline at the end of summer as 

water supplies to the lakes tend to decrease, mainly due 

to increaseing evaporation and reduced runoff. Current 

projections from July to September show above-average 

water levels for lakes Superior, Michigan-Huron and Erie 

unless exceedingly dry conditions are experienced. Lake 

Ontario is projected to be near or slightly above average 

this summer unless exceedingly wet or dry conditions 

are experienced. 

Potential range for water levels for July-Sept 

2015 compared to the long-term average 

(LTA: 1918-2014)

Temperature & Precipitation Outlook

Harmful Algal Bloom Outlook

The harmful algal bloom (HAB) season in western Lake Erie peaks annually in late summer. 

The severity of HABs is dependent on phosphorus inputs from March 1-July 31 (the “loading 

season”). Based on data from March 1-June 15, the extensive severe HABs observed in 2011 

and 2013 are not projected to occur this year. Conditions can change quickly, so this HAB 

outlook is updated weekly with the latest information. On July 9, NOAA will officially announce

the predicted western Lake Erie HAB extent for 2015. Resource and public health managers 

can use these outlooks to deal with the toxic blooms, which affect human and animal health. 

The Pierre Radisson, a Canadian 

Coast Guard icebreaker, in Lake 

Superior on 4/4/2014 

(Photo: George Leshkevich)

The Palsburg Fire in Minnesota 

on 4/15/15 (Photo: James Silverstone, US Forest Service)