Definitions of statistically downscaled agroclimatic indices

Number of days with maximum temperature above 25°C

Number of days with maximum temperature above 30°C

Number of days with maximum temperature above 33°C

Number of days with maximum temperature above 35°C

Number of days with maximum temperature above 37°C

Number of days with minimum temperature above 18°C

Number of days with minimum temperature above 20°C

Number of days with minimum temperature above 22°C

Number of days with minimum temperature above 25°C

Number of days with minimum temperature below -15°C

Number of days with minimum temperature below -20°C

Number of days with minimum temperature below -25°C

Number of days with minimum temperature below -30°C

The total number of days with a maximum temperature above 25°C during a hot spell. A hot spell is defined as 3 or more consecutive hot days.

The total number of days with a maximum temperature above 30°C during a hot spell. A hot spell is defined as 3 or more consecutive hot days.

The total number of days with a maximum temperature above 33°C during a hot spell. A hot spell is defined as 3 or more consecutive hot days.

The total number of days with a maximum temperature above 35°C during a hot spell. A hot spell is defined as 3 or more consecutive hot days.

The total number of days with a maximum temperature above 37°C during a hot spell. A hot spell is defined as 3 or more consecutive hot days.

The number of days of the longest hot spell where the maximum temperature was consecutively above 25°C.

The number of days of the longest hot spell where the maximum temperature was consecutively above 30°C.

The number of days of the longest hot spell where the maximum temperature was consecutively above 33°C.

The number of days of the longest hot spell where the maximum temperature was consecutively above 35°C.

The number of days of the longest hot spell where the maximum temperature was consecutively above 37°C.

The number of days of the longest hot spell where the minimum temperature was consecutively above 18°C.

The number of days of the longest hot spell where the minimum temperature was consecutively above 20°C.

The number of days of the longest hot spell where the minimum temperature was consecutively above 22°C.

The number of days of the longest hot spell where the minimum temperature was consecutively above 25°C.

The number of days with a maximum temperature above 30°C and a minimum temperature above 20°C in the same day.

The period between the last observed occurrence of frost (minimum temperature below 0°C) in the spring and the first observed occurrence of frost in the autumn

The period between the last observed occurrence of killing frost (minimum temperature below -2°C) in the spring and the first observed occurrence of killing frost in the autumn

The number of degrees Celsius that a day’s average temperature is below 18°C, accumulated over the heating season

The number of degrees Celsius that a day’s average temperature is above 18°C, accumulated over the cooling season

Number of days with precipitation > 1mm /day

Number of days with precipitation ≥ 10mm/day

The maximum precipitation in one day per annual cool season.

The maximum precipitation in one day per annual warm season.

The maximum precipitation in one day per annual overwintering.

The maximum precipitation accumulated over ten days per annual cool season.

The maximum precipitation accumulated over ten days per annual warm season.

The maximum precipitation accumulated over ten days per annual overwintering.

The number of days between the cool season’s start and end dates:

Start: When the weighted 5 day mean temperature ≥ 5°C has been reached for five consecutive days in first half of the year.

End: When the weighted 5 day mean daily maximum temperature ≥ 30°C has been reached for five consecutive days in July or August, or August 31, whichever occurs earlier.

The number of days between the warm season’s start and end dates:

Start: When the weighted 5 day mean temperature ≥ 10°C has been reached for five consecutive days in first half of the year.

End: When the weighted 5 day mean temperature has dropped and stayed below 10°C in second half of the year.

The number of days between the overwintering start and end dates:

Start: When the weighted 5 day mean temperature ≥ 5°C has been reached for five consecutive days in first half of the year.

End: When the weighted 5 day mean temperature has dropped and stayed below 5°C in second half of the year.

The accumulated daily Crop Heat Units (CHU) within the cool growing season.

Daily CHU = (Y_max + Y_min)/2
where Y_max = 3.33(T_max - 10) - 0.084(T_max - 10)² for
T_max ≥ 10°C, and Y_min = $\frac{9}{5}$(T_min - 4.4) for T_min ≥ 4.4°C

The accumulated daily Crop Heat Units (CHU) within the warm growing season.

Daily CHU = (Y_max + Y_min)/2
where Y_max = 3.33(T_max - 10) - 0.084(T_max - 10)² for
T_max ≥ 10°C, and Y_min = $\frac{9}{5}$(T_min - 4.4) for T_min ≥ 4.4°C

The accumulated daily Crop Heat Units (CHU) within the overwintering season.

Daily CHU = (Y_max + Y_min)/2
where Y_max = 3.33(T_max - 10) - 0.084(T_max - 10)² for
T_max ≥ 10°C, and Y_min = $\frac{9}{5}$(T_min - 4.4) for T_min ≥ 4.4°C

The accumulated daily growing degree days (GDD) values within the cool growing season multiplied by a day length factor (DLF) that equals 1.0 when the latitude (LAT) is below 49°N and 1.18 higher than 61°N. DLF = -19.3257 + 1.158643(LAT) - 0.022107689(LAT)² + 0.0001413685(LAT)³

Daily growing degree days (GDD): $GDD=\frac{T_{max}+T_{min}}{2}-C{T}_{min}$ if $\frac{T_{max}+T_{min}}{2}\ge C{T}_{min}$

CT_min: 5°C for cool season crops

The accumulated daily growing degree days (GDD) values within the warm growing season multiplied by a day length factor (DLF) that equals 1.0 when the latitude (LAT) is below 49°N and 1.18 higher than 61°N. DLF = -19.3257 + 1.158643(LAT) - 0.022107689(LAT)² + 0.0001413685(LAT)³

Daily growing degree days (GDD): $GDD=\frac{T_{max}+T_{min}}{2}-C{T}_{min}$ if $\frac{T_{max}+T_{min}}{2}\ge C{T}_{min}$

CT_min: 10°C for warm season crops

The accumulated daily growing degree days (GDD) values within the overwintering growing season multiplied by a day length factor (DLF) that equals 1.0 when the latitude (LAT) is below 49°N and 1.18 higher than 61°N. DLF = -19.3257 + 1.158643(LAT) - 0.022107689(LAT)² + 0.0001413685(LAT)³

Daily growing degree days (GDD): $GDD=\frac{T_{max}+T_{min}}{2}-C{T}_{min}$ if $\frac{T_{max}+T_{min}}{2}\ge C{T}_{min}$

CT_min: 5°C for overwintering crops