Read this bit first

This is a page on the website of a humidity app. It is not an independent roundup and it would be dishonest to present it as one.

What it can usefully do is set out the constraint every app in the category shares, and the criteria worth judging on — which you can then apply to this app as readily as to any other.

The constraint

No iPhone has a humidity sensor. Not the current models, not any previous generation, and not any mainstream Android phone either.

So no app measures the air around you. Every humidity figure on every phone comes from a weather service reporting outdoor conditions for your coordinates, based on instruments elsewhere.

That single fact settles a lot:

  • No app can tell you the humidity in your bedroom, however it is marketed.
  • No app is more accurate than another by virtue of "better sensors", because none has any.
  • Differences between apps are presentation, features and honesty — not measurement.

Any app implying it reads your immediate surroundings is claiming something impossible.

What is actually worth comparing

1. Which numbers it shows

The percentage alone is nearly useless without context, because the same percentage means very different things at different temperatures. Worth having, in order:

  • Dew point — the minimum. Comparable between conditions, and a real threshold.
  • Absolute humidity (g/m³) — the actual quantity. Very few apps show it.
  • Condensation margin — how close the air is to giving up water.
  • A comfort band — so the figure means something without a lookup.

2. Widgets

Humidity is a glance, not a session. An app you must open is an app you will stop opening. Home Screen and Lock Screen widgets are the difference between a number you check and one you do not.

3. Honesty about the source

Does it say where its data comes from and what that implies? An app presenting an interpolation from a station five miles away as though it were a measurement of your garden is overstating what it knows. The sourcing question matters more than any feature.

4. What it does with your data

A humidity app needs your coordinates and nothing else. No account, no email, no advertising identifier. Check what it asks for and what the privacy policy actually says.

What this app does

Stated plainly so you can compare it against the criteria above:

  • Shows relative humidity on a dial, with dew point, grams per cubic metre, mixing ratio, comfort band and condensation margin.
  • Widgets for Home Screen and Lock Screen, in every size.
  • Source is Apple Weather, named on the site, with the limitations described.
  • Data — coordinates are used to fetch the weather and nothing else. No account, no analytics, no advertising.
  • Does not claim an indoor reading, because it cannot have one.

If you need the indoor number

Buy a Bluetooth hygrometer. The sensing happens in the accessory, away from a warm phone and in the air you actually care about, and it pairs to iOS perfectly well.

Then calibrate it with the salt test, because consumer hygrometers are frequently several percent out of the box. No app, at any price, substitutes for a sensor that is not there.