Measurements · Meteorology
Air Temperature
Also known as ambient temperature, dry bulb, sample temp
Ambient air (dry-bulb) temperature.
What it is
What is air temperature?
Air temperature is the most basic measurement in meteorology and building comfort: the thermal state of the air, expressed in degrees Celsius. Outdoors it is set by the balance between incoming solar radiation, outgoing radiation, the warmth of the surface below, and the mixing of air masses; indoors it is governed by heating, cooling, solar gain through glazing, and the heat given off by people and equipment. Because almost every other environmental and physiological effect (how much water vapor the air can hold, how fast a body loses or gains heat, how gases behave and react) depends on it, air temperature is the reference against which most other parameters are read.
Health and operational effects
Temperature drives thermal comfort, and comfort in turn drives productivity, sleep, concentration, and complaint rates in workplaces, schools, and homes. Beyond comfort the extremes matter: cold raises cardiovascular and respiratory risk, while heat, especially combined with humidity, brings heat stress, dehydration, and, at the top end, heat stroke. Operationally, temperature governs energy use (it is the largest driver of heating and cooling loads), the risk of condensation and mold when surfaces fall below the dew point, and process conditions in laboratories, server rooms, cold chains, and manufacturing.
For facilities and safety teams temperature is both a comfort target to be held within a narrow band and an early-warning signal: a drifting server room or a failing cold store shows up first as a temperature trend.
Limits
Air Temperature Limit Values
The published values, by averaging period; each links to the standard that sets it.
Design range, operating room
- ASHRAE 170 20–24 °C: 68 to 75 °F
Air temperature is reported in degrees Celsius (°C). There is no single "safe" value. Comfort and safety bands depend on activity, clothing, humidity, and the purpose of the space, so read the figures in the limit table as context-specific ranges rather than hard pass/fail thresholds. Interpret temperature together with humidity and, where relevant, air movement and radiant heat: the same 26 °C is comfortable in dry, still air and oppressive when humid. Trends matter as much as absolutes: a steady drift outside the target band signals a control or ventilation problem.
How it is measured
How Air Temperature Is Measured
Modern electronic sensors use one of a few technologies. Thermistors (temperature-dependent resistors) are cheap, sensitive, and common in building sensors. Platinum resistance thermometers (PRT/RTD, such as the Pt100) are more accurate and stable and are the reference for meteorology. Digital semiconductor sensors integrate the sensing element and signal conditioning on a single chip. The dominant error source is not the element but its exposure: a sensor in sunlight, near a warm wall, or in the exhaust of its own electronics reads high. Outdoor meteorological measurement therefore requires a radiation shield (a louvered or aspirated screen) so the sensor reads true air temperature rather than radiant heat.
Built into Aethair PRO and Aethair IAQ2
Measured by the monitor's own sensors, calibrated before it ships: nothing to add.
An instrument on Thiamis14
A third-party instrument connected to a Thiamis gateway, reporting into the same Environet account.
Placing air temperature sensors
Indoors, mount the sensor in the occupied zone at roughly seated or standing height, away from direct sun, supply diffusers, heat-emitting equipment, and external walls that would bias it. Outdoors, house it in a ventilated radiation shield at the standard measurement height, about 1.25–2 meters above open ground, clear of buildings, paving, and heat sources that create a local microclimate. One sensor represents one thermal zone, so large or stratified spaces need several.
Every device and option that measures Air Temperature 16
| Device / option | Type | Base platform | Measures |
|---|---|---|---|
Aethair PRO built-in sensors | Built-in sensors | Aethair PRO | |
 Aethair IAQ built-in sensors | Built-in sensors | Aethair IAQ | |
 Airmar · 110WX, 110WXS, 120WX… | Weather Stations | Thiamis | |
 Thermo Scientific · pDR-1500, ADR-1500 | Particulate & Dust Monitors | Thiamis | |
 Davis · Davis Wizard III, Davis Wizard II, Davis Monitor… | Weather Stations | Thiamis | |
 Met One · E-BAM, E-BAM Plus | Particulate & Dust Monitors | Thiamis | |
 Fluke Calibration · 1620A-H, 1620A-S | Heat Stress & Comfort | Thiamis | Air TemperatureRelative Humidity |
 Lufft · WS100, WS200, WS300… | Weather Stations | Thiamis | |
 Gill Instruments · MaxiMet-GMX100, MaxiMet-GMX200, MaxiMet-GMX240… | Weather Stations | Thiamis | |
 AethLabs · MA200, MA300, MA350… | Specialty Air Analyzers | Thiamis | |
 Particles Plus · Particles Plus 5301, Particles Plus 5301-AQM1, Particles Plus 5301-AQM2… | Particulate & Dust Monitors | Thiamis | |
 Thermo Scientific · Partisol 2025i, Partisol 2025i-D, Partisol 2000i… | Particulate & Dust Monitors | Thiamis | |
 2B Technologies · POM | Specialty Air Analyzers | Thiamis | |
 TSI · QuestTemp-32, QuestTemp-34, QuestTemp-36… | Heat Stress & Comfort | Thiamis | |
 Durridge · RAD7 | Specialty Air Analyzers | Thiamis | |
 R.M. Young · 93000, 93500, 92000… | Weather Stations | Thiamis |
Where it is monitored
Solutions That Monitor Air Temperature
Each one links to the solution page showing what that industry measures it for.
Agriculture & Irrigation
Core parameterAir temperature underlies the frost warnings, growing-degree-day models, and disease-risk forecasts that modern crop management depends on.
Cleanrooms, Labs & Manufacturing
Core parameterTemperature stability is a controlled parameter in cleanrooms and laboratories, both for product and process integrity and for the comfort of gowned operators.
Healthcare Air Monitoring
Core parameterClinical ventilation guidance sets defined temperature ranges for operating rooms, recovery, pharmacy, and storage, because temperature governs both patient and staff comfort during procedures and the stability of medicines and specimens.
HVAC & Building Management
Core parameterTemperature is the primary controlled variable of any HVAC system, and monitoring it at the zone level verifies that the plant is actually delivering the setpoints occupants expect.
Indoor Air Quality
Core parameterAir temperature is the most immediate driver of occupant comfort and complaints in any building, and it interacts with humidity, ventilation, and pollutant behavior throughout an indoor space.
School Air Monitoring
Core parameterClassroom temperature swings directly affect how well students concentrate, and older school HVAC often struggles to hold a comfortable, even setpoint across a densely occupied room.
Weather Stations & Meteorology
Core parameterAir temperature is the headline measurement of any weather station, essential to forecasting, climate records, agriculture, and public safety.
Heat Stress & Outdoor Work
Often addedWBGT for worksites, athletics, and events
Outdoor Monitoring
Often addedContinuous outdoor air quality networks that sit alongside reference monitors
Article Library
Reading on Air Temperature
ASHRAE 170 Requirements and Which Edition Applies to You
ASHRAE 170 requirements explained: what the standard sets, which edition your facility is held to, what changed in 2025, and how each value gets verified.
Hospital Air Quality Monitoring: Standards by Space
Hospital air quality standards from ASHRAE 170 and The Joint Commission explained, plus what to measure in operating rooms, isolation rooms, and labs.
Workplace Air Quality Monitoring for Offices and Employers
How to monitor workplace air quality in offices, what to measure for employee health and focus, and how continuous connected monitoring documents the result.
Indoor Air Quality in Schools: Standards & Monitoring 2026
Indoor air quality in schools: which standards apply, what to monitor, and how CO2 and ventilation affect student attendance, health, and test scores.
IAQ Monitoring Parameters: PM2.5, CO2, VOCs & Formaldehyde
Indoor air quality monitoring parameters explained: PM2.5, CO2, VOCs, and formaldehyde, plus the sensors, thresholds, and OSHA, ASHRAE 62.1, and WELL limits.
Commercial Building IAQ Monitoring: ASHRAE 62.1 & WELL
Indoor air quality monitoring for commercial buildings: what to measure, which standards apply, and how property managers build a program tenants trust.
Related
More in Meteorology
Questions
Air Temperature FAQ
What is a comfortable indoor temperature?
There is no universal figure, because comfort depends on season, activity, clothing, and humidity, but most guidance frames a moderate band for occupied rooms rather than a single point. Read the range in the limit table on this page alongside humidity.
Why does my sensor read higher than the real air temperature?
Almost always because of exposure rather than a faulty element: sunlight, a nearby warm surface, or heat from the device's own electronics all bias a reading upward. Proper air-temperature measurement uses a radiation shield outdoors and careful placement away from heat sources indoors.
What is the difference between air temperature and "feels-like" temperature?
Air temperature is the physical temperature of the air. "Feels-like" values are derived indices that add other factors (the heat index folds in humidity, and wind chill folds in wind speed) to express how conditions affect the body. They are calculated from air temperature, not measured separately.
How do I monitor air temperature?
The Aethair family (Aethair PRO and Aethair IAQ) measures air temperature with a built-in sensor, alongside humidity, pressure, dew point, and heat index, so a single device covers the core meteorology and comfort set indoors. Use the configurator to combine temperature with humidity, CO₂, particulates, or an external weather station where outdoor conditions also need monitoring.
Monitor Air Temperature on the Record
Schedule a callConfigure Air Temperature Monitoring All parameters
A 30-minute call: you tell us about your application, then we demo the solution for it.