A season in context
Season comparison tool.
Growing Degree Days & Historical Season Comparison
Compare two historical seasons using recorded CSV or public gridded weather data. Explore accumulated heat, rainfall and cold days with the method visible.
Method: max(0, min(daily mean, optional cap) − base). This is not a capped-min/max or sine-curve method. No crop threshold is supplied. February 29 is excluded from both comparison sums.
Load two seasons or import two CSV files to begin.
Keep the gaps visible.
Difference is A minus B and is available only where both cumulative series are complete and start on the same month/day. Asterisked totals are sums of known values with missing days.
Make the result
mean something.
How to use Season comparison tool
- Choose two past-year windows and coordinates, or import daily date,min,max,rain CSV files. NASA data are gridded model/observation products, not garden sensors.
- Set an explicit temperature base and optional upper limit for the daily-mean GDD method. The tool does not choose a crop-specific threshold.
- Compare equal calendar positions and review missing observations before interpreting cumulative totals. Export all calculated daily values.
A worked example
For a day with 8°C minimum and 20°C maximum, the simple daily mean is 14°C. With a 10°C base and no upper cap, that day contributes 4 degree-days. Other degree-day methods can give different results.
Assumptions and scope
Temperature accumulation is a model, not a universal flowering, harvest or pest forecast. Choose a validated biological model before using any threshold for decisions. Rainfall, soil, daylight and management also matter. NASA data may lag and contain missing values; partial cumulative totals are identified.
Primary method or data reference ↗
Results use the entered values and the method described here. Keep units, sampling conditions and the source of the data with your interpretation.