About Nectarcast

Nectarcast is built by Luke Briggs, a beekeeper in Tasmania.

Why it exists

It started as a spreadsheet. Sixteen seasons of weather at one apiary showed the same amount of warmth arriving up to a month apart from one year to the next, so a diary of dates was never going to say when a flow would start. Plants are widely understood to track accumulated warmth — growing degree days — rather than the calendar. The spreadsheet became this site so that idea can be tested against real flows: every season logged, by anyone, at any apiary, pins the numbers down further, and a new apiary can start from what beekeepers nearby have already worked out.

Where it works

Nectarcast is built for Australian beekeepers. It started in north-west Tasmania, so that is where most calibrated flows are today, and every new apiary anywhere in Australia adds to what the next one nearby can borrow. Its weather is being checked against Bureau of Meteorology station records, which exist for Australia only. Sites elsewhere get the weather comparison and their own calibration, but no neighbours to learn from.

How the forecasts are made

• Weather. In Australia, daily maximum and minimum temperature and rain are from SILO (Queensland Government), which interpolates Bureau of Meteorology station records onto a 5 km grid, sixteen seasons back, under CC BY 4.0. It was chosen by checking three sources against 30 Bureau thermometers across Australia; SILO was the closest at 24 of them. The 16-day forecast, the hourly weather behind flyable hours and soil moisture, and all weather outside Australia are from Open-Meteo. Site altitude comes from Open-Meteo's elevation service.
• Growing degree days. Warmth above a 10 °C base, accumulated from 1 July.
• Thresholds. Fitted from the flows you log at each site. Nothing is invented: where there is no observation, there is no threshold.
• Forecasts. This season so far, run forward through each of the previous seasons' weather, gives a spread of dates — shown as a window, never a single day.
• Place search. Open-Meteo's geocoding service. Maps are © OpenStreetMap contributors.

Known limits

• Swarming is not well predicted by warmth; it depends on the colony as much as the weather.
• Thresholds do not transfer reliably between sites, which is why each site is fitted on its own.
• A threshold resting on one season is a first estimate, and improves with every season logged.

Cost

Free while Nectarcast is in development. Anyone who signs up during that time keeps it free for life.

Contact

Questions, bugs, a flow that did not behave: dev@nectarcast.com.