Wisconsin Summer Climate
(June, July, and August)

News/Events/Other Temperature Cooling Degree Days Precipitation

Severe Weather Heat Stress Sunrise/Sunset Holidays

MODIS Image Courtesy of WisconsinView at Space Science & Engineering Center Larger image is available

News/Events/Other

• Be aware of summertime hazards:
  • Heat waves can be deadly even in Wisconsin, claiming more lives during the last two decades than any other weather-related event. Wisconsin Heat Awareness Day will be observed on Thursday, 13 June 2013.
  • Wisconsin, along with the rest of the nation, observes Lightning Awareness Week from 23 to 29 June 2013.
  • Since Wisconsin borders on two of the Great Lakes, rip currents can pose a hazard to swimmers. The National Weather Service Offices in the Great Lakes States have joined with those along the Atlantic, Gulf and Pacific coasts in issuing rip current threat information when appropriate. The Milwaukee-Sullivan Forecast Office will participate in  Rip Current Awareness Week (2-8 June 2013).
    
     
• Many related graphs and links may be found below and on the Climate Watch and Climate Impacts pages.

Temperature

• State Map of Mean Summer Temperatures (1971-2000 normals)
• Long-term Variation in Average Summer Temperatures Statewide and:
  

  Northwest	North Central	Northeast
  West Central	Central	East Central
  Southwest	South Central	Southeast

 
• Graph of Wisconsin's Top 20 Coldest Summers and Top 20 Warmest Summers arranged by decade
• Graphic of highest state temperatures (degrees Fahrenheit) by year
• Map of Average number of 90+ degree days (1971-2000 normals)


• List of maximum number of consecutive days with 90 degrees or above temperatures for selected stations


• List of Extreme Temperatures for each station


• Temperature Data for Major Wisconsin Cities:
  

  Eau Claire	Green Bay	La Crosse
  Madison	Milwaukee	Wausau



• Long-term Variations in the Numbers of 90-degree days for Major Wisconsin Cities (current airport locations)
  

  Eau Claire	Green Bay	La Crosse
  Madison	Milwaukee	Wausau

Cooling Degree Days

A cooling degree day unit is used to estimate energy requirements for air conditioning and represents the difference between the daily average temperature and 65 degrees Fahrenheit.

• State Map of Cooling degree day units (1971-2000 normals)
• Weekly summaries of cooling degree day units by:
  
  • major city
  • population weighted by state (from Climate Prediction Center)


• Monthly summaries of cooling degree day units by:
  
  • major city
  • population weighted by state (from Climate Prediction Center)


• Archives of last 3 weeks and last three months of cooling degree day units


• List of weekly cooling degree day forecasts by state (from Climate Prediction Center)

Precipitation

• State Map of Mean Summer Precipitation (1971-2000 normals)


• Long-term Variation in Average summer precipitation Statewide and:
  

  Northwest	North Central	Northeast
  West Central	Central	East Central
  Southwest	South Central	Southeast



• Precipitation Data for Major Wisconsin Cities:
  

  Eau Claire	Green Bay	La Crosse
  Madison	Milwaukee	Wausau

• Graph of Wisconsin's Top 20 Driest Summers and Top 20 Wettest Summers arranged by decade

Severe Weather

• Severe weather events and casualties for Wisconsin between 1982-2012 from the Milwaukee/Sullivan NWS Forecast Office:
  

  Tornadoes	Thunderstorm Winds
  Lightning	Hail
  All Severe Weather Events	All Flood Events
  Number of Heat Waves**	Heat Wave Days*
  **(1982-2004)	Heat Wave Deaths*


See also Natural Hazards Climate in Wisconsin.


• Tornado Maps from NWS Milwaukee Field Office for:
  
• Tornado Maps from NWS Milwaukee Field Office for:
  

  2001	2002	2003	2004	2005	2006	2007	2008	2009	2010
  2011	2012	2013	2014	2015	2016	2015

  and annual tables for 2013 and 2014
  
  
• Wisconsin Severe Weather Climatology and Info Page from NWS Milwaukee Field Office


• Graph of annual number of Wisconsin tornadoes since 1950 according to F-scale


• Map and graph of annual number of Wisconsin tornadoes (1974-2007)


• Total number of Wisconsin tornadoes by county (1844-2007)


• Analysis of initiation times of severe weather events across Wisconsin 1982-2009
(from NWS Milwaukee)

• Number of hurricane-force wind events 75mph or greater and 100mph or greater in Wisconsin 1970-2010


• Lightning strike density patterns in the Upper Mississippi Valley
  by Kenneth R. Cook, Raúl E. López, Ronald L. Holle, and Dan A Baumgardt
  From NWSFO, La Crosse

Heat Stress

• Heat index chart from National Weather Service

Heat Stress Safety Tips from NWS including graph of U.S. Pediatric Vehicular Heatstroke Deaths since 1998

• Heat stress charts for animals from Iowa State University
  
• Interactive weather calculator from MRCC for Heat Index calculations
• Heat Index Climatology for the North Central States
  by Todd Rieck, NWSFO, La Crosse
  (A 14-page pdf file, including maps and tabulated data)
   
• Heat Index Climatology Interactive Map from MRCC
  Long-term average values of the days and hours for area stations from the Rocky Mountains to the East Coast, where the Heat Index equals or exceeds threshold values ranging from 80°F to 115°F. Monthly and annual averages are available. [MRCC GIS Maps] (NOTE MRCC also has a selection of analyzed maps of the states to the east of Rockies that show the spatial distributions of calendar year totals of the average number of days with at least one hour with Heat Index readings exceeding specified threshold readings or for days with three or more hours with similarly specified heat index thresholds.)

Sunrise/Sunset

• Time of sunrise on: 21 June, 21 July, and 21 August.
  


• Time of sunset on: 21 June, 21 July, and 21 August.
  


• Duration of sunshine on: 21 June, 21 July, and 21 August.
  

Holidays

• Memorial Day (last Monday in May)


• Independence Day (fourth of July)