The question worth measuring
How do winter outdoor moisture conditions and indoor heating relate to humidity in the rooms and enclosures we actually observe? This project is building a measured answer for Long Island. It has not yet established how often extremely low indoor humidity occurs, how widespread it is across the Northeast, or its effects on chameleon health.
We have verified outdoor records. Jason’s original room and enclosure logger exports, calibration records and test notes are still needed for the study.
Read humidity alongside temperature
Relative humidity changes with temperature as well as moisture. Warming air without adding moisture can lower its RH. Dew point helps describe the moisture in that air. Record temperature and RH together rather than relying on a percentage alone. Source: National Weather Service.
An airport, a heated room, and a perch inside an enclosure are different measurement locations. Keep their readings separate. General humidity physics does not establish a safe humidity range for any chameleon species.
Four actual outdoor observations
| UTC observation | America/New_York (EST) | Reported air °C | Reported dew point °C | Calculated outdoor RH |
|---|---|---|---|---|
| 2024-01-15 00:56 | 2024-01-14 19:56 | −0.6 | −15.0 | 32.6% |
| 2024-01-15 01:56 | 2024-01-14 20:56 | −1.1 | −15.6 | 32.2% |
| 2024-01-15 02:56 | 2024-01-14 21:56 | −1.7 | −15.0 | 35.3% |
| 2024-01-15 03:56 | 2024-01-14 22:56 | −2.2 | −15.0 | 36.7% |
Source: NOAA NCEI Global Hourly, station 72505004781 (KISP). Retrieved 26 September 2026 at 02:52:17 America/New_York (EDT). Each temperature and dew-point field carries quality code 5; the ISD specification describes this as NCEI-origin data passing the documented checks, not a guarantee of zero error.
This short excerpt demonstrates source retrieval. It was not selected as a representative winter sample and cannot establish a seasonal minimum, regional pattern or indoor condition.
What a warming calculation can show
Modeled example — indoor humidity was not measured. For the first airport record, outdoor RH calculated from −0.6°C air temperature and −15°C dew point is approximately 32.6%. If the dew point is held fixed and the temperature is hypothetically raised to 21°C, the calculation gives approximately 7.7% RH.
The assumed 21°C is an illustration, not Jason’s thermostat reading or a husbandry target. This scenario omits indoor moisture sources, air exchange, condensation and moisture buffering. It does not tell us the actual humidity inside a home or enclosure.
The NWS formula used here is es(T) = 6.11 × 10^(7.5T/(237.3+T)), with Celsius temperatures and hPa vapor pressure. Set actual vapor pressure to es(dew point), then calculate RH = 100 × e / es(air temperature). These rounded values use a liquid-water approximation; they are not laboratory precision claims.
What belongs in the measurement log
- Original timestamp, timezone, temperature, RH and the unedited source file.
- Sensor model, calibration evidence, uncertainty and exact position.
- Whether the sensor measures the room or enclosure, and whether it was sprayed or moved.
- Heating, lights, ventilation, misting, fogging, drippers and relevant maintenance.
- Species recorded by Latin name, enclosure configuration and documented changes.
Download the blank measurement CSV. The template contains no invented observations. Record unknowns as missing; never replace a missing logger reading with a modeled value and label it measured.
Calibration evidence belongs to the actual instrument. A manufacturer claim or a national reference instrument’s accuracy is not a calibration of your logger. NIST explains humidity calibration.
Read the research draft
Open the manuscript draft and methods for the question, analysis plan and evidence still required. No animal exposure trial is proposed here. Existing observations can be studied without withholding water or subjecting animals to deliberately extreme conditions.
For a larger weather analysis, NOAA now provides GHCNh as the successor to ISD. We will document station identity, release and coverage before combining records.
Sources for this page
- Islip Global Hourly observations: 15 January 2024, 00:00–03:59 UTCNOAA National Centers for Environmental Information · Observed 2024-01-15 UTC; retrieved 2026-09-26
- Discussion on HumidityNOAA National Weather Service, Louisville · Undated; checked 2026-09-26
- Vapor Pressure: temperature, dew point and relative humidity formulasNOAA National Weather Service, El Paso/Santa Teresa · Undated; checked 2026-09-26
- Federal Climate Complex data documentation: Integrated Surface DataNOAA NCEI and US Air Force 14th Weather Squadron · 2018-01-12; checked 2026-09-26
- ISD station history inventoryNOAA National Centers for Environmental Information · Retrieved 2026-09-26
- Global Historical Climatology Network hourly (GHCNh)NOAA National Centers for Environmental Information · Current page checked 2026-09-26
- HygrometersNational Institute of Standards and Technology · Updated 2022-11-28; checked 2026-09-26
Created 26 September 2026. Reviewed 26 September 2026, America/New_York. Source publication dates are preserved separately above. This educational page has not received a completed veterinary review. Research-in-progress sections retain their stated limitations.