By PulsHealth. Updated
Research reviewed .
What temperature is recorded here?
Water Temperature is the temperature of the surrounding water, saved as a discrete quantity. Apple documents automatic samples during Apple Watch Ultra dive sessions and swimming workouts. It is separate from body temperature and sleeping wrist temperature; one cannot replace the other. Apple defines the sample type.
How should units and ranges be interpreted?
Use one temperature scale for comparisons. Celsius and Fahrenheit have different zero points: °F = °C ×9/5 +32. Adding temperatures across records is not meaningful, and mixing raw numbers from different scales can create false outliers.
| Question | What to check |
|---|---|
| Is a number unusually high or low? | Scale, source, device specification and location |
| What changed during a session? | Timestamp coverage and the same temperature scale |
| Is the average representative? | Duration weighting and missing intervals |
| Is this a safe water temperature? | A reading alone cannot answer this |
Apple's Ultra underwater operating range of 0–40°C describes equipment operation, not a comfort or health range. Current Depth-app guidance also covers Series 10 and later, excluding SE 3, with capabilities that differ from Ultra. Use the actual model's specifications rather than applying one device's limits to every HealthKit record.
Why are recording intervals uneven?
HealthKit may condense or coalesce water-temperature samples. Differences between saved timestamps can reflect that storage behavior as well as a source's recording policy. A dense sensor stream and a smaller set of saved intervals need different summaries. Report missing coverage, and do not bridge a long gap as if the water had a known constant temperature.
What related information adds useful context?
Underwater depth can provide context for temperature changes at different depths when the samples share a session and adequate coverage. Swimming distance helps identify relevant activity periods. These relationships describe recorded surroundings; they do not quantify heat loss or establish a physiological response.
What did the coverage review find?
The reviewed 365-day example-data window contained no samples, stored aggregates or workout-series points for this type. Value distributions, unusual readings, recording cadence and related-data comparisons could not be measured. No empirical figure is presented; missing database rows do not establish missing records on the phone.
Does PulsHealth collect this type?
This identifier is part of HealthKit, but is not listed in the current PulsHealth sync catalog. The units above describe HealthKit measurement semantics rather than a promised sync format. Database coverage and Apple Health availability are separate questions.
Understanding your records
Recording frequency, source and coverage affect what you can conclude from this data. Read the recording guide.
- One record
- Environmental water temperature; distinct from body and sleeping wrist temperature.
- Frequency
- Source-dependent contributions, spot readings or recorded intervals; no empirical cadence was available.
- Context
- Interpret timing and source method for the specific measurement; timestamp overlap does not establish shared session identity.
- Coverage and gaps
- No observations in the reviewed reporting window; database absence is not a zero reading or proof of absence on the phone.
- Summaries
- Discrete values are not cumulative totals. Use compatible units, durations, coverage and source methods for summaries.
- Metadata
- Optional source metadata does not establish complete measurement method or context; no records were available to inspect.
Recording guidance reviewed 2026-10-14