Pick a field and press “Get conditions.”
Delta-T Bands
| ΔT °C | Verdict | What it means |
|---|---|---|
| < 2 | CAUTION | Air is near-saturated. Droplets don’t shrink properly and low-wind calm air can trap spray near the ground. Check wind before starting. |
| 2 – 8 | IDEAL | Droplets evaporate to the right size and reach the target. Standard spray window for all products. |
| 8 – 10 | MARGINAL | Evaporation is fast. Systemic herbicides only — glyphosate, dicamba, 2,4-D, clethodim. These absorb into the plant before the droplet dries. Contact products and fungicides lose efficacy here. Finish before conditions worsen. |
| > 10 | DO NOT SPRAY | Too dry. Droplets evaporate before they land. Coverage and efficacy are poor regardless of product. |
Wind Bands
| Wind | Verdict | What it means |
|---|---|---|
| < 3 mph | CAUTION | Too calm. Still air traps spray near the ground and increases inversion risk. Droplets can drift unpredictably even with no perceptible wind. |
| 3 – 10 mph | IDEAL | Good air movement for coverage and canopy penetration. Drift is manageable with standard nozzle selection. |
| 10 – 15 mph | MARGINAL | Drift risk increasing. Use larger droplet nozzles, reduce boom height, spray away from sensitive areas. |
| > 15 mph | DO NOT SPRAY | Drift is uncontrollable. Spray will not land on target regardless of nozzle or boom height. |