Cloche

Cloche turns a thermometer and a hygrometer reading into the one thing worth knowing: what to do about it. Entirely on your phone. No account, no signal, no subscription.

WHAT IT ANSWERS
1. Is this house too wet, too dry, or where it should be?
2. Would opening the vents help - or make it worse?
3. Is the glass about to run with water?
4. And on the heat it has actually had, when does this crop come off?

VENTING IS A COMPARISON, NOT A RULE
Every grower knows the wet-morning instinct: it feels damp in here, so open up. Sometimes that is exactly wrong.
- Relative humidity is a percentage of a capacity, and warm air has far more capacity than cold air. 85% outside at 20C is a great deal more water than 70% inside at 16C.
- Cloche converts both air masses to GRAMS OF WATER PER CUBIC METRE - the only figure comparable across a temperature difference - and says which way the water would actually move.
- On that morning it will tell you not to vent, show you the grams that would come in, and name heat as the only lever that lowers humidity without importing moisture.

DEFICIT, NOT PERCENTAGE
The number a crop responds to is vapour pressure deficit: how much more water the air could still hold. Cloche puts the live deficit against the band your crop wants and keeps it on screen on every tab. A leaf runs cooler than the air around it, so leaf deficit is gentler than air deficit - the offset is yours to set.

IT REFUSES RATHER THAN GUESSES
- Humidity with no temperature is not a reading. The same 80% is comfortable at 18C and stops transpiration at 28C, so the app declines and says why.
- With no outside reading there is no venting advice - but rather than shrug, it inverts the question: here is what this house holds, and here is the temperature the covering would start running at.
- Fewer than seven readings and no harvest date is offered. What it gives instead is the count it has and the count it needs.

CONDENSATION, BEFORE IT HAPPENS
The inner face of a covering sits colder than the air, by an amount that depends on what the covering is - single glass gives up half the difference, triple-wall polycarbonate under a fifth. Cloche works out that face temperature, compares it with the dew point and tells you the margin in degrees, plus the outside temperature at which it would start.

WHAT IS IN IT
- Live deficit, dew point, absolute humidity and the band, on every tab
- The lever: vent, heat, both, damp down, or leave it alone - with the reason
- The two air masses side by side in g/m3, and which way the water moves
- Condensation margin per covering, and the temperature it begins at
- Degree days above each crop's own base temperature, and the date they project
- A house register with covering, area, screen and heat
- A log carrying the derived figures beside the two you wrote down
- Insights: houses out of band, houses running wet, houses where venting would wet, and the deficit over time with the crop's band drawn behind it
- A shipped reference for 14 protected crops and 6 coverings, exportable
- Export to JSON and CSV; backup and restore
- Celsius or Fahrenheit; kPa or millibars; light and dark themes

PRIVACY
No account. No ads. No analytics. No third-party SDKs. No data collected and none shared. The app requests no runtime permissions at all. Its single network request is loading the privacy policy in Settings; everything else works in flight mode.

The crop bands and base temperatures are published guides, not a warranty. Your own house, your own variety and your own light levels beat any table.