USA - NOAA releases updated climate summaries for all U.S. states. What will happen in Michigan?

EAST LANSING, MI. — Temperatures in Michigan have risen nearly three degrees Fahrenheit since the beginning of the 20th century and continued warming is expected for the remainder of this century, causing environmental impacts on lake levels, precipitation patterns and more.

What are the State Climate Summaries?

In response to the third national climate assessment (NCA) in 2017, the National Atmospheric and Oceanic Administration (NOAA) National Centers for Environmental Information produced state climate summaries to address the need for more detailed state level predictions. Updated in 2022, these summaries allow users to select any state in the U.S. from an online interactive map and explore key messages, read a full narrative and download figures from the report. Each state summary includes a description of historical climate conditions with input sought from state climatologists and NOAA regional climate centers to provide context for predicted future impacts. Similarly, future climate scenarios are based on reputable, previously published sources of data and focus on physical climate and coastal issues.

What history tells us in Michigan

The state climate summary for Michigan highlights the unique climatic features of the state including the large seasonal changes in temperature and the moderating effects of the Great Lakes. In particular:

• The Lakes’ moderating effect is evident along the shores and allows Michigan to be more temperate and moist than other north-central states.

• Temperatures in the state have been higher in the 2000s than in any other historical period, with warming concentrated in the winter and spring seasons.

• Annual maximum ice coverage on the Great Lakes during 2000 through 2021 was 47%, compared to the 1973 through 1999 average of 58%.

• The frequency of extreme precipitation events has increased. The average number of two-inch extreme precipitation events for 2010 through 2014 and 2015 through 2020 are the highest on record.

• Great Lakes water levels have fluctuated between three to six feet since the late 19th century. Over the last few decades, water levels on average have declined slightly for most of the Great Lakes according to the EPA and hit record lows in 2013. However, annual average lake levels have risen rapidly since 2013, breaking records in 2020.

What we expect for Michigan’s future


• While the Great Lakes region has already experienced an increase of 2.3° Fahrenheit, annual average temperatures are expected to exceed historical levels by mid-century under most emissions pathways (“emissions pathways” refer to projected human induced greenhouse gas emissions over the 21st century).

• Extreme heat is a concern for urban areas like Detroit due to the urban heat island effect whereby dense concentration of pavement and buildings combined with high temperatures and humidity cause dangerous heat index values.

• Higher spring temperatures may lengthen the growing season. However, crops may be increasingly susceptible to spring freeze damage when blooms caused by early season warm temperatures are followed by freezing conditions.

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