Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Climate
Climate Normal Calculator
Compute a climate anomaly as the standardised z-score of a current value against the 30-year average and standard deviation. Values outside ±2 indicate statistically unusual conditions.
Fill in the required fields to see your result.
Climate
Evapotranspiration Calculator
Estimate monthly potential evapotranspiration (PET) from average temperature, daylight hours, and days in the month using a simplified Thornthwaite-style formula. Returns millimetres of water lost per month.
Fill in the required fields to see your result.
Key differences
| Climate Normal Calculator | Evapotranspiration Calculator | |
|---|---|---|
| Category | Climate | Climate |
| Inputs required | 3 | 3 |
| Result | Climate Anomaly (standard deviations) | Potential Evapotranspiration (mm/month) |
| What it does | Compute a climate anomaly as the standardised z-score of a current value against the 30-year average and standard deviation. Values outside ±2 indicate statistically unusual conditions. | Estimate monthly potential evapotranspiration (PET) from average temperature, daylight hours, and days in the month using a simplified Thornthwaite-style formula. Returns millimetres of water lost per month. |