Stationsweb Help - Agricultural Weather

This page offers numerous measured and calculated values relevant to agriculture.

Growing Degree Days

Growing Degree Days (GDD) measure heat accumulation to estimate plant and insect development. They are calculated by summing the mean daily temperatures above a base threshold specific to a given species or crop. GDD help predict growth stages and optimal harvest times. The formula below shows the calculation of Growing Degree Days (“GDD”) on day “i” given temperature values “T”.

Grassland Temperature Sum

The Grassland Temperature Sum (GTS) is a metric used in Central Europe to determine the start of the growing season for grasslands. It is calculated by summing daily mean temperatures above 0 °C, with values below 0 °C set to zero. A weighting system is applied that reduces the importance of earlier months: January values are weighted at 0.5× and February values at 0.75×. The formula below shows the calculation of the Grassland Temperature Sum (“GTS”) on day “i” given temperature values “T”.

Page Content

Widgets

The following values are displayed as widgets at the top of the page, depending on data completeness and available sensors:

• Precipitation – precipitation in the last 24 h, last 7 days and last 30 days; time since last precipitation
• Growing Degree Days – last value for the selected reference period with the selected base temperature
• Grassland Temperature Sum – last value for the selected reference period
• Wet-bulb temperature – current value, daily minimum and maximum
• Leaf moisture – current value, daily minimum and maximum
• Soil moisture – current value, daily minimum and maximum

Graphs

The following graphs are displayed below the widgets:

• Grassland Temperature Sum for the selected reference period and average over all valid periods
• Detailed Grassland Temperature Sum with a shaded limit value
• Growing Degree Days for the selected reference period and average over all valid periods with the set base temperature
• Detailed Growing Degree Days

Prerequisites

The following data requirements must be met for each value to be available:

• Precipitation – precipitation sensor values required
• Growing Degree Days & Grassland Temperature Sum – at least 90% of hourly temperature readings must be available per year (full year for previous years; up to the current date for the current year)
• Wet-bulb temperature – current temperature and humidity values required
• Leaf moisture – leaf moisture sensor values required
• Soil moisture – soil moisture sensor values required