# Definitions of statistically downscaled climate indices

## There are 49 statistically downscaled climate indices

Index | Definition | Unit |
---|---|---|

Hot days (Tmax > 25°C) |
Number of days with maximum temperature above 25°C |
Days |

Hot days (Tmax > 30°C) |
Number of days with maximum temperature above 30°C |
Days |

Hot days (Tmax > 33°C) |
Number of days with maximum temperature above 33°C |
Days |

Hot days (Tmax > 35°C) |
Number of days with maximum temperature above 35°C |
Days |

Hot days (Tmax > 37°C) |
Number of days with maximum temperature above 37°C |
Days |

Hot nights (Tmin > 18°C) |
Number of days with minimum temperature above 18°C |
Days |

Hot nights (Tmin > 20°C) |
Number of days with minimum temperature above 20°C |
Days |

Hot nights (Tmin > 22°C) |
Number of days with minimum temperature above 22°C |
Days |

Hot nights (Tmin > 25°C) |
Number of days with minimum temperature above 25°C |
Days |

Cold days (Tmin < -15°C) |
Number of days with minimum temperature below -15°C |
Days |

Cold days (Tmin < -20°C) |
Number of days with minimum temperature below -20°C |
Days |

Cold days (Tmin < -25°C) |
Number of days with minimum temperature below -25°C |
Days |

Cold days (Tmin < -30°C) |
Number of days with minimum temperature below -30°C |
Days |

Hot spell days (Tmax consecutive 3 day > 25°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. |
Days |

Hot spell days (Tmax consecutive 3 day > 30°C) |
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. |
Days |

Hot spell days (Tmax consecutive 3 day > 33°C) |
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. |
Days |

Hot spell days (Tmax consecutive 3 day > 35°C) |
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. |
Days |

Hot spell days (Tmax consecutive 3 day > 37°C) |
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. |
Days |

Longest hot spell days (where Tmax > 25°C) |
The number of days of the longest hot spell where the maximum temperature was consecutively above 25°C. |
Days |

Longest hot spell days (where Tmax > 30°C) |
The number of days of the longest hot spell where the maximum temperature was consecutively above 30°C. |
Days |

Longest hot spell days (where Tmax > 33°C) |
The number of days of the longest hot spell where the maximum temperature was consecutively above 33°C. |
Days |

Longest hot spell days (where Tmax > 35°C) |
The number of days of the longest hot spell where the maximum temperature was consecutively above 35°C. |
Days |

Longest hot spell days (where Tmax > 37°C) |
The number of days of the longest hot spell where the maximum temperature was consecutively above 37°C. |
Days |

Longest hot spell nights (where Tmin > 18°C) |
The number of days of the longest hot spell where the minimum temperature was consecutively above 18°C. |
Days |

Longest hot spell nights (where Tmin > 20°C) |
The number of days of the longest hot spell where the minimum temperature was consecutively above 20°C. |
Days |

Longest hot spell nights (where Tmin > 22°C) |
The number of days of the longest hot spell where the minimum temperature was consecutively above 22°C. |
Days |

Longest hot spell nights (where Tmin > 25°C) |
The number of days of the longest hot spell where the minimum temperature was consecutively above 25°C. |
Days |

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

Frost free days |
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 |
Days |

Killing frost free days |
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 |
Days |

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

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

Number of days with precipitation > 1mm |
Number of days with precipitation > 1mm /day |
Days |

Number of days with precipitation ≥ 10mm |
Number of days with precipitation ≥ 10mm/day |
Days |

Cool season annual one-day maximum precipitation |
The maximum precipitation in one day per annual cool season. |
mm/day |

Warm season annual one-day maximum precipitation |
The maximum precipitation in one day per annual warm season. |
mm/day |

Overwintering annual one-day maximum precipitation |
The maximum precipitation in one day per annual overwintering. |
mm/day |

Cool season annual ten-day maximum precipitation |
The maximum precipitation accumulated over ten days per annual cool season. |
mm/10d |

Warm season annual ten-day maximum precipitation |
The maximum precipitation accumulated over ten days per annual warm season. |
mm/10d |

Overwintering annual ten-day maximum precipitation |
The maximum precipitation accumulated over ten days per annual overwintering. |
mm/10d |

Length of growing season for cool season crops |
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. |
Days |

Length of growing season for warm season crops |
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. |
Days |

Length of growing season for overwintering crops |
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. |
Days |

Cool season crop heat units |
The accumulated daily Crop Heat Units (CHU) within the cool growing season.
Daily CHU = (Y |
Heat unit |

Warm season crop heat units |
The accumulated daily Crop Heat Units (CHU) within the warm growing season.
Daily CHU = (Y |
Heat unit |

Overwintering crop heat units |
The accumulated daily Crop Heat Units (CHU) within the overwintering season.
Daily CHU = (Y |
Heat unit |

Cool season effective growing degree days |
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) 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 |
°C-day |

Warm season effective growing degree days |
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) 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 |
°C-day |

Overwintering effective growing degree days |
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) 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 |
°C-day |