Rainfall Tracker

Enter rainfall amounts for each day of the week from your rain gauge or weather report.

Weekly Water Needs

Each plant type has a known optimal weekly water requirement, typically expressed in inches of water. This accounts for both rainfall and any supplemental irrigation.

Effective Rainfall

Not all rainfall reaches plant roots equally. Light drizzle may evaporate before soaking in, while heavy downpours can run off. As a general rule, about 80% of measured rainfall is considered effective for garden plants in well-drained soil.

Deficit Calculation

The tracker compares effective weekly rainfall against each plant's water requirement. A positive deficit means supplemental watering is needed. A negative deficit (surplus) means natural rainfall has exceeded the plant's needs.

Interpreting Results

• Surplus — Rainfall exceeds plant needs. No supplemental watering required. Ensure drainage is adequate to prevent waterlogging.
• Adequate — Rainfall meets plant needs within 10%. Monitor soil moisture but irrigation is likely unnecessary.
• Slight deficit — Rainfall covers most needs but a small top-up may benefit sensitive plants. Check soil moisture before watering.
• Deficit — Significant shortfall. Supplemental watering is needed to keep plants healthy.