ZoneFlow

Rain gauges and weather stations

ZoneFlow subtracts rain from what it waters, lets wet soil dry out first and stops a watering when it starts raining. For that it needs one rain sensor per outdoor zone (Configure → Zone settings → Rain gauge sensor). Since 1.6.5 that does not have to be a tipping bucket. ZoneFlow understands the rain sensors of most weather stations too. Tell it which kind you picked under Rain gauge sensor type.

If you have no rain sensor at all, see Rain without a gauge. If you want to build a cheap tipping bucket, see A cheap DIY rain gauge.

Which type to choose

  • Tip counter: the sensor is a count that goes up by one with every tip of the bucket, such as an ESPHome or Zigbee tipping bucket or a counter helper. Set the size of one tip on the zone's device page, Rain Gauge mm per Tip.
  • Rain total: the sensor is a running rain total in millimetres or inches that only goes up (lifetime, yearly or "total rain"), or one that starts again every day, week or month ("daily rain", "weekly rain"). The drop back to zero is not read as rain. This is the best choice when your station has one.
  • Rain per reading: the sensor gives the amount that fell since the previous reading, as the Tempest Precipitation sensor does. Every reading is added up, repeated readings included.
  • Rain rate: the sensor gives the current rain in millimetres (or inches) per hour. ZoneFlow adds the rate up over time, so it is less exact than a total. A reading counts for at most 15 minutes, so a sensor that stops updating does not keep adding rain.

Sensors that only say "rain in the last hour" or "rain in the last 24 hours" cannot be used. Those values go up and down, so they cannot be added up. Pick a total, a per-reading amount or a rate from the same station instead, or use the Weather Underground option.

When a sensor is in inches or centimetres, ZoneFlow converts it to millimetres by itself. Rain Gauge mm per Tip is only used for a tip counter and is hidden for the other types.

Common stations

This is what the Home Assistant integrations offer, from their documentation. The names can differ by version, and none of it has been tried with the real hardware yet.

  • Ecowitt (and the Froggit, Misol and Fine Offset clones): Rainfall (a lifetime total), Daily, Weekly, Monthly and Yearly rainfall (totals that start again) and Rain rate. Use Rainfall or Yearly rainfall as a Rain total. Daily rainfall works too.
  • Ambient Weather: Lifetime rain, Yearly, Monthly, Weekly and Daily rain, Event rain, Last 24 hours rain (rolling, so not usable) and an hourly rate. Use Lifetime rain or Daily rain as a Rain total.
  • WeatherFlow Tempest: Precipitation is the amount over the previous minute, and Precipitation intensity is a rate. Use Precipitation as Rain per reading.
  • Netatmo rain module: Rain (the latest measurement), Rain last hour (rolling, off by default) and sum_rain_24, which Home Assistant reports as a total that goes up. Netatmo describes it as the rain of the day, though some users report a rolling 24 hours. Check it against your own gauge before relying on it. If it behaves like a daily total, use Rain total.
  • Davis WeatherLink: usually a daily total and a rate. Use the daily total as a Rain total.
  • Your own tipping bucket (ESPHome, Zigbee, Tuya, rtl_433 over MQTT): a tip counter is a Tip counter. If it already reports millimetres, use Rain total.

Good to know

  • The first reading when ZoneFlow starts is a starting point, not rain. A lifetime total of 1,234 mm does not count as 1,234 mm of rain.
  • ZoneFlow keeps a timestamped running total for 15 days. Every rain window, from 15 minutes up to 14 days, is the difference between two points of it.
  • Changing the sensor or the type starts the rain history again. The rain windows and Rain Today begin at zero.
  • The "raining now" checks for the last 15, 30 and 60 minutes need a sensor that reports often. A station that reports only every few minutes still works, but those short windows react more slowly.
  • A sensor that reports the same value again, such as a steady rate or 0.2 mm twice, is counted on Home Assistant 2024.4 or newer.
  • A zone without any rain sensor waters as if it never rains. You can still enter rain by hand or use Weather Underground.