Past, Present, and Future Climate of Marquette, Michigan

Marquette, Michigan, sits on the south shore of Lake Superior and exemplifies a cold, lake-dominated climate whose character is already shifting under anthropogenic climate change. This paper synthesizes Marquette’s historic climate (approximately 1951 to present), its current 1991–2020 climatological normals, and model-based projections through the end of the 21st century, drawing on station data from the Great Lakes Integrated Sciences and Assessments (GLISA), regional assessments, and local adaptation plans.

Current climatology (1991–2020)

Temperature

GLISA’s 1991–2020 summary for Marquette reports an annual mean temperature of 43.8°F (6.6°C), with a mean high of 51.1°F and mean low of 36.6°F. January averages 18.5°F and July–August averages 66.2°F. The city sees about 2.2 days per year above 90°F and 142.5 days at or below 32°F. About 11–12 days per year drop to 0°F or below.

This combination of long, cold winters and modestly warm summers defines Marquette’s “snowbelt maritime continental” character: distinctly continental but smoothed by Lake Superior.

Precipitation and snowfall

Average annual precipitation is approximately 30 inches, with relatively even distribution across months. September and October are the wettest months, February and March the driest.

Snowfall is where Marquette stands out. NOAA data list 149.1 inches of average annual snowfall, much of it from lake-effect snow, making Marquette one of the snowiest locations in the contiguous United States. Other compilations put the average closer to 155–200 inches. Persistent snow cover is typical, with winter snow depth often exceeding 10 inches and snow cover lasting from late November into April.

The average window for morning freezes extends from roughly October 15 to May 7, implying a relatively short frost-free season.

Historic climate change

Warming since mid-century

GLISA’s Marquette station trends for 1951–2024 show annual mean temperature increasing by 2.1°F, with winter warming of 3.2°F and fall warming of 2.7°F. Spring warming was minimal at 0.4°F and summer at 1.0°F. These changes are consistent with and slightly above the Great Lakes regional average warming of 2.3°F since 1951.

Precipitation redistribution

Annual precipitation change has been essentially flat, but with seasonal redistribution: winter precipitation increased by about 1.3%, fall by 5.0%, while spring decreased by 4.1% and summer by 4.2%. The pattern is consistent across analyses: somewhat drier warm seasons and wetter cool seasons, even though annual totals have not changed drastically.

At the Great Lakes scale, GLISA reports a 14% increase in annual precipitation since 1951, with a marked increase in rain falling in the heaviest 1% of storms. Marquette lies in a subregion (western Upper Peninsula) that saw smaller or even declining totals despite the broader regional increase.

Lake Superior warming and ice decline

Lake Superior summer surface water temperature increased approximately 4.5°F from 1979–2006, roughly double the rate of regional atmospheric warming. Surface water temperatures are increasing almost twice as fast as air temperatures, and 2012 recorded a 71°F surface temperature, the warmest in the instrumental record. About a 70% decline in Great Lakes ice cover has occurred since the 1970s, with Lake Superior among those showing the largest losses.

These changes directly affect Marquette’s climate by enhancing lake-effect processes, modifying lake-land temperature contrasts, and increasing shoreline erosion.

Extremes and recent anomalies

Recent events illustrate the evolving climate: long-running stations at Marquette, Sault Ste. Marie, and Houghton had their wettest March on record in 2025. The early 2010s featured a series of very warm years, including record-warm March 2010 and 2012’s record Lake Superior water temperatures that forced beach closures due to bacterial contamination linked to warm waters.

Modeled future climate

Temperature projections

GLISA’s Great Lakes projections, based on downscaled CMIP ensembles, project average annual air temperatures increasing by 3–6°F by approximately 2050 and 6–11°F by 2100, with northern areas warming faster than the regional average, particularly in winter. Marquette, which historically has rarely exceeded 90°F, is expected to experience around two weeks per year above 90°F by mid-century — a substantial change from the current 2–3 days per year.

Overnight lows are projected to warm faster than daytime highs, intensifying heat stress. The frost-free season, already lengthened by roughly 1–2 weeks, may extend by 1–2 months by 2100 under high-emissions scenarios.

Precipitation and extreme events

The amount of precipitation falling in the heaviest 1% of storms increased by 42% in the Midwest between 1958 and 2016. Projections indicate total annual precipitation will continue to increase with strong seasonal variation — wetter winters and springs, somewhat drier summers — and heavier, more frequent extreme events.

For Marquette, the existing trend toward wetter fall and winter and drier spring and summer aligns with regional projections and is likely to continue or intensify.

Snow, winter precipitation, and lake-effect

Lake-effect snowfall has increased in areas downwind of Lakes Michigan and Superior, linked to warmer lake surfaces and reduced ice cover. Near to mid-century, Marquette is likely to remain a heavy-snow snowbelt city, with potential for even more intense lake-effect events, especially during early and mid-winter when the lake is warm and largely ice-free.

Late in the century, a rising fraction of cold-season precipitation will fall as rain or freezing rain rather than snow, particularly in shoulder months. Total seasonal snowfall may decline even if individual snowstorms remain capable of producing very large accumulations.

Lake Superior’s future

Summer surface water temperatures in Lake Superior are projected to rise by as much as 7°F by 2050 and approximately 12°F by 2100. Some models suggest typical winters with little or no open-lake ice by around 2040, punctuated by occasional high-ice winters during strong Arctic outbreaks. Earlier onset of stratification and later turnover will lengthen the period in which the lake can warm.

Discussion

The observational and modeling evidence converges on several key points: substantial warming, especially in winter and fall; seasonal precipitation redistribution rather than dramatic annual change; rapid warming and ice loss in Lake Superior; and a future climate that is warmer, more variable, and more extreme. By mid-century, Marquette likely experiences warmth equivalent to shifting several hundred kilometers south in terms of growing season length and hot-day frequency, while still retaining a lake-moderated character.

Marquette’s direct lake exposure intensifies lake-effect snow and fog, extends the season of lake-moderated temperatures, and means that simple scaling from regional projections can mislead — local lake-effect processes may cause Marquette to retain deep-winter cold and heavy snowfall longer than warmer inland locations, even as its climate warms substantially.

Key uncertainties include snowfall trends and projections (observational snowfall series are noisy and sensitive to station practices), lake-land feedbacks (future lake levels, ice cover, and near-shore currents remain challenging to model at city scale), and socio-climatic interactions (migration, land-use change, and adaptation investments will strongly modulate realized risk).

Conclusions

Marquette’s climate has historically been defined by long, snowy winters, cool summers, and strong lake moderation. Observations since the mid-20th century show that this climate is warming markedly, with winter and fall warming especially pronounced and evidence of changing seasonal precipitation and more intense extreme events. Looking forward, by mid-century Marquette will be several degrees warmer, experience many more hot days, and see a longer growing season. By late century, warming could reach levels that fundamentally alter winter conditions, shifting a large share of cold-season precipitation from snow toward rain. In the near term, Marquette is poised to remain a snow-rich, winter-dominated city but with increasing climatic volatility.

Sources

1. GLISA Station Climatology, Marquette — 1991–2020 normals (temperature, precipitation, freeze days) and 1951–2024 station trends by season.
2. GLISA Summary of Climate Change in the Great Lakes Region (October 2024) — regional average warming (2.3°F since 1951), 14% precipitation increase, and downscaled CMIP projections for the Great Lakes.
3. NOAA NCEI U.S. Climate Normals (1991–2020) — snowfall totals and supplementary station data for Marquette.
4. Austin & Colman 2007, “Lake Superior summer water temperatures are increasing more rapidly than regional air temperatures” — source for 4.5°F Lake Superior surface warming (1979–2006).
5. NOAA GLERL Great Lakes Ice Cover Database — ice-cover decline data, including approximately 70% loss since the 1970s.
6. GLISA Great Lakes Ice Coverage — ice-cover trends and Lake Superior projections.
7. NWS Marquette Climate Reports — recent climate anomalies, including wettest March 2025 on record.
8. Fourth National Climate Assessment, Chapter 21: Midwest — source for 42% increase in heavy precipitation (1958–2016) and regional climate projections.