Definitions of statistically downscaled agroclimatic indices
Statistically downscaled agroclimatic indices for CMIP5 (CanDCS-U5, 49 indices) and CMIP6 (CanDCS-U6 and CanDCS-M6, 67 indices) are defined below. Note that the 18 indices in the list, marked with a ‘*’, are only available for the CMIP6 datasets.
| Index | Definition | Unit |
|---|---|---|
| Hot days (Tmax > 25 °C) (tx25) |
Number of days with maximum temperature above 25 °C |
Days |
| Hot days (Tmax > 30 °C) (tx30) |
Number of days with maximum temperature above 30 °C |
Days |
| Hot days (Tmax > 33 °C) (tx33) |
Number of days with maximum temperature above 33 °C |
Days |
| Hot days (Tmax > 35 °C) (tx35) |
Number of days with maximum temperature above 35 °C |
Days |
| Hot days (Tmax > 37 °C) (tx37) |
Number of days with maximum temperature above 37 °C |
Days |
| Hot nights (Tmin > 18 °C) (tn18) |
Number of days with minimum temperature above 18 °C |
Days |
| Hot nights (Tmin > 20 °C) (tn20) |
Number of days with minimum temperature above 20 °C |
Days |
| Hot nights (Tmin > 22 °C) (tn22) |
Number of days with minimum temperature above 22 °C |
Days |
| Hot nights (Tmin > 25 °C) (tn25) |
Number of days with minimum temperature above 25 °C |
Days |
| Cold days (Tmin < -15 °C) (tnm15) |
Number of days with minimum temperature below -15 °C |
Days |
| Cold days (Tmin < -20 °C) (tnm20) |
Number of days with minimum temperature below -20 °C |
Days |
| Cold days (Tmin < -25 °C) (tnm25) |
Number of days with minimum temperature below -25 °C |
Days |
| Cold days (Tmin < -30 °C) (tnm30) |
Number of days with minimum temperature below -30 °C |
Days |
| Hot spell days (Tmax consecutive 3 day > 25 °C) (txc25) |
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) (txc30) |
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) (txc33) |
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) (txc35) |
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) (txc37) |
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) (txlc25) |
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) (txlc30) |
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) (txlc33) |
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) (txlc35) |
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) (txlc37) |
The number of days of the longest hot spell where the maximum temperature was consecutively above 37 °C. |
Days |
| * Hot spell nights (TN > 18 °C, for 3-Days) (tnc18) |
The total number of days with a minimum temperature above 18 °C during a hot spell. A hot spell is defined as 3 or more consecutive hot days. |
Days |
| * Hot spell nights (TN > 20 °C, for 3-Days) (tnc20) |
The total number of days with a minimum temperature above 20 °C during a hot spell. A hot spell is defined as 3 or more consecutive hot days. |
Days |
| * Hot spell nights (TN > 22 °C, for 3-Days) (tnc22) |
The total number of days with a minimum temperature above 22 °C during a hot spell. A hot spell is defined as 3 or more consecutive hot days. |
Days |
| * Hot spell nights (TN > 25 °C, for 3-Days) (tnc25) |
The total number of days with a minimum temperature above 25 °C during a hot spell. A hot spell is defined as 3 or more consecutive hot days. |
Days |
| Longest hot spell nights (where Tmin > 18 °C) (tnlc18) |
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) (tnlc20) |
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) (tnlc22) |
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) (tnlc25) |
The number of days of the longest hot spell where the minimum temperature was consecutively above 25 °C. |
Days |
| * Cold spell nights (TN < -15 °C, for 3-Days) (tnmc15) |
The total number of days with a minimum temperature below 15 °C during a cold spell. A cold spell is defined as 3 or more consecutive cold days. |
Days |
| * Cold spell nights (TN < -20 °C, for 3-Days) (tnmc20) |
The total number of days with a minimum temperature below 20 °C during a cold spell. A cold spell is defined as 3 or more consecutive cold days. |
Days |
| * Cold spell nights (TN < -25 °C, for 3-Days) (tnmc25) |
The total number of days with a minimum temperature below 25 °C during a cold spell. A cold spell is defined as 3 or more consecutive cold days. |
Days |
| * Cold spell nights (TN < -30 °C, for 3-Days) (tnmc30) |
The total number of days with a minimum temperature below 30 °C during a cold spell. A cold spell is defined as 3 or more consecutive cold days. |
Days |
| * Longest cold spell length nights (TN < -15 °C, for 3-Days) ( tnlm15) |
The number of days of the longest cold spell where the minimum temperature was consecutively below 15 °C. |
Days |
| * Longest cold spell length nights (TN < -20 °C, for 3-Days) ( tnlm20) |
The number of days of the longest cold spell where the minimum temperature was consecutively below 20 °C. |
Days |
| * Longest cold spell length nights (TN < -25 °C, for 3-Days) ( tnlm25) |
The number of days of the longest cold spell where the minimum temperature was consecutively below 25 °C. |
Days |
| * Longest cold spell length nights (TN < -30 °C, for 3-Days) ( tnlm30) |
The number of days of the longest cold spell where the minimum temperature was consecutively below 30 °C. |
Days |
| Hot day and night (hot) |
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 (ff) |
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 (kff) |
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 (hdd) |
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 (cdd) |
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 (prep1) |
Number of days with precipitation > 1mm /day |
Days |
| Number of days with precipitation ≥ 10mm (prep10) |
Number of days with precipitation ≥ 10mm/day |
Days |
| Cool season annual one-day maximum precipitation (p1d_gsc) |
The maximum precipitation in one day per annual cool season. |
mm/day |
| Warm season annual one-day maximum precipitation (p1d_gsw) |
The maximum precipitation in one day per annual warm season. |
mm/day |
| Overwintering annual one-day maximum precipitation (p1d_gso) |
The maximum precipitation in one day per annual overwintering. |
mm/day |
| Cool season annual ten-day maximum precipitation (p10d_gsc) |
The maximum precipitation accumulated over ten days per annual cool season. |
mm/10d |
| Warm season annual ten-day maximum precipitation p10d_gsw) |
The maximum precipitation accumulated over ten days per annual warm season. |
mm/10d |
| Overwintering annual ten-day maximum precipitation p10d_gso |
The maximum precipitation accumulated over ten days per annual overwintering. |
mm/10d |
| Length of growing season for cool season crops (gsc) |
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 |
| * Cool growing season start (gscs) |
Start: When the weighted 5-day mean temperature ≥ 5 °C has been reached for five consecutive days in first half of the year. |
Day of the year |
| * Cool growing season end (gsce) |
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. |
Day of the year |
| Length of growing season for cool season crops (gsc) |
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 |
| * Warm growing season start (gsws) |
Start: When the weighted 5-day mean temperature ≥ 5 °C has been reached for five consecutive days in first half of the year. |
Day of the year |
| * Warm growing season end (gswe) |
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. |
Day of the year |
| Length of growing season for warm season crops (gsw) |
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 |
| * Overwinter growing season start (gsos) |
Start: When the weighted 5-day mean temperature ≥ 10 °C has been reached for five consecutive days in first half of the year. |
Day of the year |
| * Overwinter growing season end (gsoe) |
End: When the weighted 5-day mean temperature has dropped and stayed below 10 °C in second half of the year. |
Day of the year |
| Length of growing season for overwintering crops (gso) |
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 (cchu_gsc) |
The accumulated daily Crop Heat Units (CHU) within the cool growing season.
Daily CHU = (Ymax + Ymin)/2 |
Heat unit |
| Warm season crop heat units (cchu_gsw) |
The accumulated daily Crop Heat Units (CHU) within the warm growing season.
Daily CHU = (Ymax + Ymin)/2 |
Heat unit |
| Overwintering crop heat units (cchu_gso) |
The accumulated daily Crop Heat Units (CHU) within the overwintering season.
Daily CHU = (Ymax + Ymin)/2 |
Heat unit |
| Cool season effective growing degree days (egdd_gsc) |
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): if CTmin: 5 °C for cool season crops |
°C-day |
| Warm season effective growing degree days (egdd_gsw) |
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): if CTmin: 10 °C for warm season crops |
°C-day |
| Overwintering effective growing degree days (egdd_gso) |
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): if CTmin: 5 °C for overwintering crops |
°C-day |