Heat Index (2024)

La Crosse, WI

Weather Forecast Office

Weather.gov > La Crosse, WI > Heat Index

Heat Index
Temperature vs. Humidity

How to read the chart: find the temperature on the left hand side, then move to the right until you find the column for the approximate relative humidity. That number will be the temperature that it will "feel" like. Example: A temperature of 95 and relative humidity of 50% will "feel" like 107 degrees.

0%5%10%15%20%25%30%35%40%45%50%55%60%65%70%75%80%
115103107111115120127135143151
11099102105108112117123130137143151
1059597100102105109113118123129135142149
1009193959799101104107110115120126132136144
958788909193949698101104107110114119124130136
90838485868788909193959698100102106109113
857879808182838485868788899091939597
807374757677777879798081818283858686
756969707172727373747475757676777778
706464656566666767686869697070707071

IMPORTANT: Heat index values were devised for shady, light wind conditions. Exposure to full sunshine can increase values by up to 15 degrees! Also, strong winds, particularly with very hot, dry air, can be extremely hazardous.

Or, if you know the temperature and the dewpoint, figure out the heat index and relative humidity (RH) using this calculator.

HEAT INDEX using Temp and Dew Point

HEAT INDEX using Temp and RH

Dew Point vs. Humidity

The dew point is the temperature the air needs to be cooled to (at constant pressure) in order to achieve a relative humidity (RH) of 100%. At this point the air cannot hold anymore water in the gas form. If the air were to be cooled even more, water vapor would have to come out of the atmosphere in the liquid form, usually as fog or precipitation.

The higher the dew point rises, the greater the amount of moisture in the air. This directly effects how "comfortable" it will feel outside. Many times, relative humidity can be misleading. For example, a temperature of 30 and a dew point of 30 will give you a relative humidity of 100%, but a temperature of 80 and a dew point of 60 produces a relative humidity of 50%. It would feel much more "humid" on the 80 degree day with 50% relative humidity than on the 30 degree day with a 100% relative humidity. This is because of the higher dew point.

So if you want a real judge of just how "dry" or "humid" it will feel outside, look at the dew point instead of the RH. The higher the dew point, the muggier it will feel.

General comfort levels that can be expected during the summer months:

  • less than or equal to 55: dry and comfortable
  • between 55 and 65: becoming "sticky" with muggy evenings
  • greater than or equal to 65: lots of moisture in the air, becoming oppressive
Heat Index/Heat Disorders
Heat IndexPossible heat disorders for people in higher risk groups
80-90Fatigue possible with prolonged exposure and/or physical activity.
90-105Sunstroke, heat cramps and heat exhaustion possible with prolonged exposure and/or physical activity.
105-130Sunstroke, heat cramps or heat exhaustion likely, and heat stroke possible with prolonged exposure and/or physical activity.
130 or higherHeatstroke/sunstroke highly likely with continued exposure.
Heat DisorderSymptomsFirst Aid
SunburnRedness and pain. In severe cases swelling of skin, blisters, fever, and headaches.Ointments for mild cases if blisters appear and do not break. If breaking occurs, apply dry sterile dressings. Serious, extensive cases should be seen by a physician.
Heat CrampsPainful spasms usually in muscles of the legs and abdomen possible. Heavy sweating.Firm presure on the cramping muscles, or gentle massaging to relieve the spasm. Give sips of water. If nausea occurs, discontinue use.
Heat ExhaustionHeavy sweating, weakness, skin cold, pale and clammy. Pulse thready. Normal temperature possible. Fainting and vomiting.Get victim out of sun. Lay down and loosen clothing. Apply cool, wet cloths. Fan or move victim to air conditioned room. Sips of water. If nausea occurs, discontinue use. If vomiting continues, seek immediate medical attention.
Heat Stroke (sunstroke)High body temperature (106 F or higher). Hot dry skin. Rapid and strong pulse. Possible unconsciousness.Heat stroke is a severe medical emergency. Summon emergency medical assistance or get the victim to a hosiptal immediately. Delay can be fatal.

Move the victim to a cooler environment. Reduce body temperature with cold bath or sponging. Use extreme caution. Remove clothing, use fans and air conditioners. If temperature rise again, repeat process. Do not give fluids.

Safety Tips
  • Slow down. Strenuous activities should be reduced, eliminated, or rescheduled to the coolest time of the day. Individuals at risk should stay in the coolest available place, not necessarily indoors.
  • Dress for summer. Lightweight, light-colored clothing reflects heat and sunlight, and helps your body maintain normal temperatures.
  • Foods (like proteins) that increase metabolic heat production also increase water loss.
  • Drink plenty of water or non-alcoholic fluids. Your body needs water to keep cool. Drink plenty of fluids even if you don't feel thirsty.
  • Do not drink alcoholic beverages.
  • Spend more time in air-conditioned places. Air conditioning in homes and other buildings markedly reduces danger from the heat. If you cannot afford an air conditioner, spending some time each day (during hot weather) in an air conditioned environment affords some protection.
  • Don't get too much sun. Sunburn makes the job of heat dissipation that much more difficult.
Heat Index (2024)
Top Articles
Latest Posts
Article information

Author: Jonah Leffler

Last Updated:

Views: 5897

Rating: 4.4 / 5 (65 voted)

Reviews: 88% of readers found this page helpful

Author information

Name: Jonah Leffler

Birthday: 1997-10-27

Address: 8987 Kieth Ports, Luettgenland, CT 54657-9808

Phone: +2611128251586

Job: Mining Supervisor

Hobby: Worldbuilding, Electronics, Amateur radio, Skiing, Cycling, Jogging, Taxidermy

Introduction: My name is Jonah Leffler, I am a determined, faithful, outstanding, inexpensive, cheerful, determined, smiling person who loves writing and wants to share my knowledge and understanding with you.