# Garden Weather Tasks

> Frost warnings, watering you can skip after rain, and litres per bed from the MET Norway forecast. Reads the MET Norway forecast for your garden and turns it into garden tasks for the coming days: frost and cold-night warnings for tender plants in the ground, days when rain makes watering unnecessary, hot days, and how many litres each bed needs from FAO-56 crop water use — with the best days to water.

Part of usefulweb.site (https://usefulweb.site/). Part of [Greenplot](https://greenplot.usefulweb.site/) (ownerApp: greenplot). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://greenplotweathertasks.usefulweb.site/ (interactive tool at https://greenplotweathertasks.usefulweb.site/tool)
- JSON API: POST https://greenplotweathertasks.usefulweb.site/api/v1/calculate with a JSON object of inputs (schema: https://greenplotweathertasks.usefulweb.site/api/v1/tool)
- OpenAPI: https://greenplotweathertasks.usefulweb.site/openapi.json
- MCP (Streamable HTTP): https://greenplotweathertasks.usefulweb.site/mcp - tool `greenplot_weather_tasks`

## Inputs
- place (text, required): Place (latitude, longitude) - Decimal degrees such as “52.47, 13.40”. Rounded to 0.01° (about 1 km).
- timeZone (text): Time zone of the place
- days (integer): Days ahead
- plantings (table): Plantings

## Method
- Fetches the MET Norway Locationforecast 2.0 for the place (rounded to 0.01°) through Hearth’s cached client, which honours MET’s Expires and If-Modified-Since rules, and groups the hours into complete local days (at least 20 forecast hours).
- Frost: a day with a minimum of 1 °C or lower while a tender or half-hardy plant is in the ground (planted or sown before that day) → protect it with fleece or bring pots in; ground frost often comes at 1–3 °C air temperature. Cold night: a minimum of 4 °C or lower while tender plants (tomatoes, beans, courgettes …) are out. Hot day: a maximum of 30 °C or more.
- Skip watering: a day with 5 mm of rain or more, or the day after one; established beds need no extra water then.
- Litres per bed: Hearth’s FAO-56 watering need — Penman–Monteith reference evapotranspiration from the forecast, times the crop coefficient of each plant and its growth stage, minus the rain that reaches the roots (80 % of daily rain over 2 mm) — with one soaking per about 12 mm of need, placed on evenly spread days that are not skip days.

## Limits
- Forecasts change; frost in hollows and on clear, still nights can come earlier than forecast for the area. Containers and greenhouses need more water.