ET₀ Record
See how much water the weather is taking, what rain gives back, what greens and tees used, and where the figures come from
The ET₀ Record shows how much water the weather is taking from your turf, against the rain that gives it back.
Open Course › Weather › ET₀ Record. It needs Premium.
What is ET₀?
ET₀ (reference evapotranspiration) is the water a standard grass surface loses in a day to sun, wind, warmth and dry air, in millimetres. Your greens and tees use ET₀ multiplied by their crop factor — the same figures the irrigation model uses.
TurfWise works ET₀ out each night from your weather history. A new club sees No ET₀ records yet until a few days are in.
What does the top card tell me?
It covers This week — the last seven days:
- Weather took (ET₀) — the total, the daily average and the peak day.
- Rain gave back — the rain over the same days.
- Greens used and Tees used — roughly what each surface lost, shown with its crop factor.
Rain logged so far today shows underneath.
The card also says how much water greens and tees are holding. That needs your watering, so until last night's is logged it says We can't say yet rather than guess.
Save time
Click Log last night's watering right on the card. It's the same sheet as Irrigation, so you only enter it once.
What's further down?
The week ahead
What the weather is forecast to take each day, against forecast rain, with the range the forecasts give. Forecast days are never added to the record.
Weather against rain
A chart of the window you choose: 30d, 90d, 6 mo or 12 mo. Or use Count from to start from a date — clicking a day or week on the chart does the same.
The running total is rain minus ET₀ only. It ignores watering and how much the soil can hold, so use it to compare weeks and summers, not to set tonight's programme.
The record
Your history folded into weeks, with what the weather took, the rain, the peak day and how sure each week is. Click a week to see its days.
Where the figures come from
Shows which stretches came from your own weather station and which from the weather service, how sure each is (High, Medium or Low), and what would make them surer. A station without a sun sensor has its sunshine estimated, so its days read Low.