Wisconsin Climate – July 2026 Update
Top 5 Cities: Milwaukee, Madison, Green Bay, Kenosha, and Racine
Summary
Wisconsin experienced its 7th warmest July on record as an intense mid-summer heat dome brought severe warmth and stifling humidity across the state. Temperatures reached 40°C in several communities for the first time in three years, while unusually high night-time humidity offered little overnight relief. Below-average rainfall further intensified dry conditions across southern and central counties, with warmer-than-average conditions expected to persist into late summer.
This month in numbers
The state recorded an average temperature of 22.61°C in July 2026, sitting 2.0°C above the 1961-1990 baseline to rank 7th warmest in 77 years of data. Daytime maximum temperatures averaged 28.94°C, which was 1.8°C warmer than baseline and also ranked as the 7th highest on record. Precipitation remained sparse, with Wisconsin receiving just 74.68 mm of rainfall, 21.1 mm below average, making it the 66th driest July on record.
What changed
Looking at the broader three-month period from May to July 2026, average temperatures reached 17.91°C (+0.9°C anomaly), placing the season as 17th warmest on record, while three-month rainfall totalled 231.65 mm (-48.6 mm anomaly), ranking 69th lowest. Globally, land temperatures reached historic levels, with the month ranking 3rd warmest (+1.6°C anomaly) and the May-to-July three-month period ranking 2nd warmest (+1.5°C anomaly) in 87 years of records. Regionally, Wisconsin was the 2nd warmest state in the NOAA Upper Midwest group (US Upper Midwest), running slightly above the four-state average anomaly of +1.95°C.
What’s driving change?
The elevated temperatures were primarily driven by atmospheric that trapped unseasonably warm, humid air masses over the central United States, amplified by broader that slowed the movement of weather systems. These persistent high-pressure ridge conditions prevented cool polar air from pushing south, allowing to further warm the lower atmosphere as ground moisture evaporated. Active weather events remained elevated during the period. All of Wisconsin's two wildfires this year have happened in the past month, tracked on our live map at Extreme Weather tracker.
Looking ahead
Seasonal forecasts from NOAA indicate a high probability that warmer-than-average temperatures will continue across the Upper Midwest through late summer and into autumn.
Generated by Gemini from climate data and web sources
At a Glance
Temperature – Average
Climate Map – USUnited States
Source: NOAA Climate at a Glance — US states & climate regions (tavg, pcp), plus GPCC (Snow, water-equivalent). Anomalies are vs the 1961–1990 baseline. See methodology.
Typical Climate – Wisconsin
Köppen Dfb · ContinentalWisconsin has a continental climate (Köppen Dfb: Humid continental - warm summer), with both a warm/cold cycle and a wet/dry cycle through the year. July is typically the warmest month, averaging 21.1°C, while January is the coldest at -8.2°C. Annual precipitation averages around 903mm, concentrated mostly in the wet season.
Monthly climate normals (2016–2025) - bar colour and height show average temperature, the shaded area shows average monthly rain, with snow (water-equivalent) shown separately.
Data: NOAA National Centers for Environmental Information (temperature/precipitation; frost: World Bank CCKP; snow: GPCC (DWD)).
Long-Term Trends
Combined Timeline – Wisconsin
Precipitation, Sunshine, Frost and Snow are converted to standard deviations from their own average so they can share an axis with Temperature.
Data: NOAA National Centers for Environmental Information (temperature/precipitation; frost: World Bank CCKP; snow: GPCC (DWD)).
Heatwave Days – Wisconsin
Warm Spell Duration Index (WSDI) - days in a 6+ day run above the local 90th-percentile temperature for that time of year.
Data: World Bank Climate Change Knowledge Portal (ERA5-derived). Refreshed roughly 1-2x/year, ~7-8 months behind present.
Year-on-Year Trends
The 4byo Climate Helix – Wisconsin
Data: NOAA National Centers for Environmental Information (temperature/precipitation; frost: World Bank CCKP; snow: GPCC (DWD)).
Monthly Temperature – Wisconsin
Background lines show the last 40 years (plus the record year and its opposite, wherever they fall).
Data: NOAA National Centers for Environmental Information (temperature/precipitation; frost: World Bank CCKP; snow: GPCC (DWD)).
Records – Wisconsin
NOAA National Centers for Environmental Information (frost: World Bank CCKP; snow: GPCC (DWD)) - Anomalies vs 1901-2000 mean
Shifting Seasons
Warm/cold + wet/dryKöppen Dfb · ContinentalWisconsin has both a clear warm/cold cycle (±16.0°C) and a wet/dry cycle (4× wet:dry ratio). Both sides of the annual rhythm are shown below.
Monthly precipitation climatology. A “wet month” exceeds the baseline monthly mean (dashed gold line). Biggest month-to-month shift: Oct (+20 mm, +34%).
Data: NOAA National Centers for Environmental Information (temperature/precipitation; frost: World Bank CCKP; snow: GPCC (DWD)).
Emissions & Energy
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Data Sources
Data Sources for Wisconsin
Every figure on this page is sourced from official, openly published climate datasets. Anomalies are calculated against the 1961–1990 baseline (temperature) and 1991–2020 (rainfall, sunshine, frost) - see the Methodology & Sources page for the complete dataset list and update calendar.
Statewide monthly temperature and precipitation (nClimDiv).
Frost Days and Heatwave Days (Warm Spell Duration Index), ERA5-derived. World Bank Climate Change Knowledge Portal.
Monthly snow water-equivalent, Global Precipitation Climatology Centre (DWD).
FAQs
FAQs
How is the climate in Wisconsin changing?
Wisconsin is warming in line with the rest of the world. The page above shows the latest monthly temperature anomaly versus the 1961-1990 baseline, the long-term annual trend, and the region's rank in the historical record. The headline panel also shows the long-term trend rate per decade and the warmest and coolest years on file.
What is the climate like in Wisconsin?
Wisconsin has a continental climate (Köppen Dfb: Humid continental - warm summer), with both a warm/cold cycle and a wet/dry cycle through the year. July is typically the warmest month, averaging 21.1°C, while January is the coldest at -8.2°C. Annual precipitation averages around 903mm, concentrated mostly in the wet season.
Where does the climate data for Wisconsin come from?
Climate data for Wisconsin comes from NOAA Climate at a Glance (temperature and precipitation), refreshed every month, when the upstream temperature and rainfall data are refreshed.
What is the climate baseline used on this page?
Anomalies on this page are calculated against the 1961-1990 climatological baseline, which is the standard reference period used by the Met Office, NOAA, IPCC and most national climate services. Some panels also show the source-native 1901-2000 (NOAA) or 1991-2020 (WMO) baselines for verification. See Methodology & Sources for the full reference.
Which areas does the Wisconsin climate data cover?
The Wisconsin climate profile covers Milwaukee, Madison, Green Bay, Kenosha and surrounding areas. Wisconsin climate data from NOAA Climate at a Glance
How often is the Wisconsin climate update refreshed?
The Wisconsin climate update is refreshed monthly, typically a few days after the previous month closes and the upstream provider (Met Office HadUK-Grid, NOAA Climate at a Glance, Copernicus ERA5 or the Global Carbon Project) publishes its update. See the Climate Rankings for cross-region comparisons.
What counts as a Heatwave Day on the Wisconsin climate page?
Heatwave Days use the Warm Spell Duration Index (WSDI) - the WMO/ETCCDI-standard heatwave measure: days that are part of a run of 6 or more consecutive days above the local 90th-percentile temperature for that calendar day. The 90th-percentile threshold varies by time of year (a hot day in January is judged differently to one in July) but is fixed to the 1961-1990 baseline for every year shown - it does not shift as the climate warms, which is why Heatwave Days trend upward over time.
Does the Wisconsin climate page include frost and snow data?
Yes. Frost Days (days with a minimum temperature below 0°C, World Bank CCKP) and snow water-equivalent (GPCC) are shown alongside temperature and precipitation, each measured against the 1961-1990 baseline where a like-for-like historical comparison is available.