How AgriIntel's weather and spray windows work
AgriIntel uses OpenWeather forecasts for each farm's weather point. The spray strip scores the next 8 forecast slots of 3 hours each (24 hours) on wind, temperature and rain chance. A slot with no wind reading is marked unknown, never calm. It is planning information: the product label and an on-site reading decide.
Last updated November 5, 2026
Before you start
- A farm with a weather point. See add a farm.
- To try the rules without an account, use the farm check on the homepage. It scores a nearby town, not your farm.
Where the numbers come from
- Forecasts and current conditions come from OpenWeather for the farm's stored coordinates, through AgriIntel's own server. They are model forecasts and a nearby observation, not readings from a sensor on your farm.
- Responses are cached for up to 15 minutes, so the same numbers can be shown for a short while after you reload.
- Current conditions show the observation time, for example "Observed 9:40 PM", in farm-local time.
- The daily forecast covers about five days. Each day's wind is its peak forecast wind, and its rain figure is the highest chance of rain among that day's forecast periods. Late in the evening today can drop off the list.
How each spray slot is rated
The strip takes the first 8 slots of the 3-hourly forecast. Each slot is labelled with its forecast time in the farm's local time and rated on three values together.
| Rating | Wind | Temperature | Rain chance |
|---|---|---|---|
| Good | 3 to 15 km/h | 10 to 25°C | 15% or less |
| Caution | Under 3 km/h, or 15 to 20 km/h | 5 to 10°C, or 25 to 30°C | Above 15% |
| Not suitable | Above 20 km/h | Below 5°C or above 30°C | 30% or more |
| Unknown | No wind in the forecast | Any | Any |
- The worst value decides: one value in the Not suitable band makes the slot Not suitable, and one in the Caution band makes it Caution.
- Wind under 3 km/h is Caution because very calm air can mean an inversion and drift.
- Rain chance is the forecast probability of precipitation, not an amount.
- The best spray window is the longest unbroken run of Good slots; the earliest wins a tie. It never spans a slot that is not Good. If no slot is Good, the strip says there are no suitable windows in the next 24 hours.
Missing or unavailable data
- Missing wind is never treated as calm. A slot without wind is Unknown and shows "— km/h".
- If no slot has wind, the strip shows Spray guidance unavailable instead of a window.
- If the forecast cannot be loaded, the screen says weather data is unavailable. AgriIntel never fills in placeholder numbers.
What the rating does not consider
The rating does not look at wind direction, gusts, humidity, delta T, rain-free intervals, the crop, the product or buffer zones. Health Canada's Pest Management Regulatory Agency manages spray drift through mitigation statements on each product's label, so the label's limits apply even when a slot is rated Good. Take a wind reading at the field before and during the job.
Limits
- Forecasts carry forecast uncertainty and describe one point, not your fields. Low spots and calm nights can differ from the forecast.
- A Good rating is not a clearance to spray and not agronomic advice.
- There is no hourly observation feed or on-farm weather station connection.
- Weather is calculated for the farm's weather point, not for each field.
Next step
Sources
- Health Canada: Drift MitigationSupports: PMRA mitigates spray drift through mitigation statements on pesticide labels. Last reviewed November 5, 2026.
