Wet Bulb Temperature Calculator

Athletic Training & Sports

Coaches and athletic trainers use wet bulb temperature to modify practice intensity and duration. Sports organizations establish mandatory protocols for activity restrictions at specific wet bulb thresholds to prevent heat-related illnesses in athletes.

Examples: Practice modifications, fluid replacement protocols, mandatory rest periods, heat illness prevention, athletic competition safety

Military Operations

Military forces use wet bulb temperature to establish combat load restrictions, exercise duration limits, and mandatory rest-recovery cycles for personnel. Heat casualty prevention is critical during field training and operations.

Examples: Training intensity control, combat load management, rest schedules, heat casualty prevention, operational planning

Occupational Safety

Employers in construction, manufacturing, agriculture, and outdoor industries use wet bulb standards to protect worker safety. OSHA and other regulatory bodies reference wet bulb thresholds for workplace safety requirements.

Examples: Work-rest schedules, mandatory hydration breaks, equipment modifications, medical surveillance, hazard communication

Public Health & Emergency Response

Public health agencies use wet bulb forecasts to issue heat warnings and activate cooling center protocols. Emergency responders use wet bulb data for resource planning during heat events.

Examples: Heat warning systems, cooling center activation, vulnerable population outreach, hospital preparedness, emergency coordination

Medical Monitoring

Clinicians and occupational health providers use wet bulb temperature to guide monitoring frequency for heat-exposed workers. Medical surveillance increases when wet bulb exceeds critical thresholds.

Examples: Pre-shift medical screening, vital sign monitoring, heat illness diagnosis, treatment guidance, return-to-work decisions

Research & Analysis

Researchers use wet bulb temperature data to study heat stress physiology, validate safety protocols, and develop improved heat illness prevention strategies.

Examples: Thermal comfort research, safety protocol validation, climate impact assessment, prevention strategy development, occupational health studies

Dry Bulb Temperature

The actual air temperature has the most direct impact on wet bulb temperature. As dry bulb temperature increases, wet bulb temperature rises proportionally, increasing heat stress risk. Temperature is measured in Celsius or Fahrenheit.

Relative Humidity

Humidity dramatically affects wet bulb temperature by reducing evaporative cooling effectiveness. High humidity means the air already contains significant moisture, limiting the body's ability to cool through perspiration and sweat evaporation.

Atmospheric Pressure

Atmospheric pressure affects saturation vapor pressure and evaporation rates. Higher pressure at sea level versus high altitude influences how much cooling evaporation can provide, affecting wet bulb calculations and heat stress assessment.

Wind Speed & Air Movement

Air movement enhances evaporative cooling, lowering wet bulb temperature. Still air reduces evaporation, increasing heat stress, while wind can significantly reduce heat stress risk through improved cooling.

Solar Radiation

Direct sunlight adds thermal stress beyond air temperature effects. Clear, sunny conditions increase the actual heat stress experienced, while cloud cover and shade reduce thermal load significantly.

Clothing & Equipment

Insulating clothing and protective equipment reduce evaporative cooling effectiveness. Heavy, waterproof, or tight-fitting clothing traps heat, increasing core body temperature and heat stress risk substantially.

Activity Level & Metabolic Heat

Exercise and work generate internal metabolic heat, adding to environmental heat stress. Higher activity intensity increases heat production, requiring greater evaporative cooling for thermal balance.

Individual Acclimatization

Heat acclimatization improves the body's thermal regulation and heat tolerance. Individuals accustomed to hot conditions can tolerate higher wet bulb temperatures, while unacclimatized individuals face greater heat illness risk.

What is the difference between wet bulb and heat index?

Wet bulb temperature measures actual evaporative cooling capacity and is the preferred metric for heat stress assessment in occupational and athletic settings. Heat index combines temperature and humidity but doesn't directly measure cooling effectiveness. Wet bulb is more accurate for determining when activity restrictions are needed.

What wet bulb temperature is considered dangerous?

Generally, wet bulb temperatures above 32°C (90°F) represent extreme danger where even sedentary individuals face severe heat illness risk. Above 28°C (82°F) represents danger for active individuals. Above 24°C (75°F) requires caution for strenuous activities. The exact threshold depends on activity level and individual acclimatization.

How do I measure wet bulb temperature myself?

Measure dry bulb temperature with a regular thermometer and relative humidity with a hygrometer. Use this calculator to compute wet bulb temperature from these measurements. A psychrometer is the traditional instrument for direct wet bulb measurement but is less commonly used now.

Can wet bulb temperature exceed dry bulb temperature?

No, wet bulb temperature is always lower than or equal to dry bulb temperature. It equals dry bulb temperature only when relative humidity is 100% (saturated air). As humidity decreases, the difference between wet bulb and dry bulb increases.

Why does wet bulb matter for outdoor workers?

Wet bulb temperature determines the body's ability to cool itself through sweat evaporation. When wet bulb exceeds the body's cooling capacity, dangerous heat accumulation occurs, risking heat exhaustion and heat stroke. OSHA and workplace safety regulations increasingly use wet bulb thresholds to protect workers.

How often should I recalculate wet bulb during heat events?

Update calculations every 15-30 minutes during heat events or when conditions change significantly. Temperature and humidity fluctuate throughout the day, affecting heat stress risk. Frequent updates ensure current safety protocols match actual conditions.

Is wet bulb temperature used in sports medicine?

Yes, wet bulb temperature is essential in athletic training. Coaches use wet bulb thresholds to modify practice intensity, mandate rest periods, and implement hydration protocols. High school and collegiate sports organizations increasingly adopt wet bulb-based guidelines to prevent heat illnesses.

What does atmospheric pressure do in wet bulb calculations?

Atmospheric pressure affects saturation vapor pressure and evaporation rates. Higher pressure increases the saturation vapor pressure, affecting how much moisture the air can hold. For most practical applications at sea level, using 1013.25 hPa is acceptable.

Can I use this calculator indoors?

Yes, this calculator works for any location where you can measure or know the dry bulb temperature and relative humidity. Indoor spaces with different atmospheric conditions can also be evaluated using actual pressure measurements.

How accurate is the Stull formula used in this calculator?

The Stull formula provides excellent accuracy for practical heat stress assessment in the range of -40°C to 50°C and 0% to 100% relative humidity. For research requiring maximum precision, more complex formulas exist, but Stull provides sufficient accuracy for safety applications.