Dew point explains the sticky feeling
Relative humidity changes with temperature. Dew point better reflects how much moisture is actually in the air, and how easily sweat can evaporate.
US SUMMER HEAT & COOLING ATLAS
Your State's Summer Heat Playbook
Summer is not one kind of hot. Choose a state for a detailed guide to humidity, UV, cooling methods and practical summer planning.
Built from typical summer climate patterns, not a live local forecast.
50-state climate logicDry vs humid heat scienceDetailed state profiles
THE SCIENCE IN PLAIN ENGLISH
Why the same fan can feel brilliant in one state and underwhelming in another
Dry heat rewards evaporation
In dry air, damp towels, skin wetting, fine mist and evaporative cooling can feel more effective because the air can take on more moisture.
Humid heat changes the playbook
When air is already moisture-heavy, mist and evaporative coolers lose their edge. Air conditioning, shade and personal airflow become the practical layers.
HEAT SAFETY FIRST
Personal cooling is a comfort layer, not an emergency plan.
During heat alerts, air conditioning, cool spaces, water, rest and shade matter more than any small device. If someone is confused, faints, has a seizure, is unconscious or has hot, dry skin, call 911.
COMMON QUESTIONS
Summer heat, decoded
Why does humid heat feel so much worse?
Your body relies heavily on sweat evaporating from the skin. Humid air slows that evaporation, so you retain more heat and can feel hotter than the thermometer suggests.
Are misting fans better in dry weather?
Usually. Fine water droplets are most useful where the surrounding air can absorb that moisture. In sticky weather, mist can sit on the skin instead of evaporating quickly.
Can I rely on a fan in an extreme heat event?
No. A fan can improve comfort, but it does not replace air conditioning, a cool public space, hydration, rest or urgent care. Take extra care with fan-only cooling in very hot, dry indoor conditions.
Why does this tool use climate patterns rather than today's weather?
This is an evergreen planning guide. It explains what each state's summer is commonly like; always follow current local weather and public-health alerts.
METHOD AND SOURCES
How this atlas makes recommendations
The logic starts with a state's typical summer moisture pattern, then layers in temperature, dew point, humidity, UV, cooling-method fit and whether air-conditioned recovery should be the priority in serious heat. Statewide figures are planning guides, not street-level forecasts.
National Weather Service: why dew point mattersUSGS: evaporative coolingCDC: heat and healthOSHA: water, rest and shadeNEJM: fan use and skin wetting
Heat response varies by age, health, medication, hydration, acclimatisation, clothing, sun exposure and activity. This guide is educational only and does not replace public-health warnings, workplace heat plans or emergency care.
Help Us Improve
We built this tool to be genuinely helpful. If you have any suggestions on how we can improve it, let us know!