diff --git a/CHANGELOG.md b/CHANGELOG.md
index e5a5b829f..48ceea6a0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,6 +33,13 @@
 
 ## 2025
 
+### 5 Dec 2025
+
+- [change] Removed `BaseTMethod` parameter from HDD/CDD calculations (#144)
+  - Model now always uses weekday/weekend-specific base temperatures (`BaseT_Heating`, `BaseT_Cooling`)
+  - Simplifies anthropogenic heat flux calculation logic
+  - `BaseTMethod` in legacy input files is now ignored
+
 ### 3 Dec 2025
 - [feature] Improved albedos ranges (ge=0.0 and le=1.0) in Field of Pydantic classes for alb_id, air_ssa_lw, air_ssa_sw, veg_ssa_lw, veg_ssa_sw (PR #978)
 - [feature] Improved ranges (ge=0.0) in Field of Pydantic classes for preciplimitalb, roof_albedo_dir_mult_fact, and ground_albedo_dir_mult_fact. (PR #978)
diff --git a/docs/source/inputs/tables/RunControl/scheme_options.rst b/docs/source/inputs/tables/RunControl/scheme_options.rst
index af7b36d94..585906969 100644
--- a/docs/source/inputs/tables/RunControl/scheme_options.rst
+++ b/docs/source/inputs/tables/RunControl/scheme_options.rst
@@ -46,15 +46,17 @@ Scheme options
 
 .. option:: BaseTMethod
 
+	.. deprecated:: v2025a
+
+		This option has been removed. The model now always uses weekday/weekend-specific
+		base temperatures (``BaseT_Heating`` and ``BaseT_Cooling``) for HDD/CDD calculations.
+		If present in legacy input files, this parameter is ignored.
+
 	:Requirement:
-		Required
+		Optional (ignored)
 	:Description:
-		Determines method for base temperature used in HDD/CDD calculations.
-	:Configuration:
-		.. csv-table::
-			:file: csv-table/BaseTMethod.csv
-			:header-rows: 1
-			:widths: 10 80
+		Previously determined method for base temperature used in HDD/CDD calculations.
+		Now deprecated in favour of always using weekday/weekend-specific base temperatures.
 
 .. option:: EmissionsMethod
 
diff --git a/src/suews/src/suews_ctrl_const.f95 b/src/suews/src/suews_ctrl_const.f95
index 1b1ff8ca3..655179de9 100644
--- a/src/suews/src/suews_ctrl_const.f95
+++ b/src/suews/src/suews_ctrl_const.f95
@@ -1143,7 +1143,6 @@ MODULE module_ctrl_const_datain
 
    ! ---- Model options set in RunControl --------------------------------------------------------
    INTEGER :: EmissionsMethod, & ! anthropogenic emissions method
-              BaseTMethod, & ! base temperature method for HDD/CDD calculations used in QF module
               CBLuse, & !CBL slab model used (1) or not used (0)
               MultipleMetFiles, & !Indicates whether a single met file is used for all grids (0) or one for each grid (1)
               MultipleInitFiles, & !Indicates whether a single initial conditions file is used for all grids (0) or one for each grid (1)
diff --git a/src/suews/src/suews_phys_dailystate.f95 b/src/suews/src/suews_phys_dailystate.f95
index 6581ac7a3..f07f6853f 100644
--- a/src/suews/src/suews_phys_dailystate.f95
+++ b/src/suews/src/suews_phys_dailystate.f95
@@ -83,8 +83,6 @@ SUBROUTINE SUEWS_cal_DailyState( &
       TYPE(SUEWS_STATE), INTENT(INOUT) :: modState
 
       ! INTEGER :: WaterUseMethod
-      INTEGER, PARAMETER :: BaseTMethod = 2 ! base t method [-]
-      REAL(KIND(1D0)), PARAMETER :: BaseT_HC = 18.2 !base temperature for heating degree dayb [degC] ! to be fully removed TODO
 
       ! TYPE(IRRIGATION_PRM), INTENT(IN) :: irrPrm
       ! INTEGER :: Ie_start !Starting time of water use (DOY)
@@ -504,12 +502,10 @@ SUBROUTINE SUEWS_cal_DailyState( &
                ! regular update at all timesteps of a day
                IF (execute_subroutines) THEN
                   CALL update_DailyState_Day( &
-                     BaseTMethod, &
                      DayofWeek_id, &
                      avkdn, & !input
                      Tair, &
                      Precip, &
-                     BaseT_HC, &
                      BaseT_Heating, BaseT_Cooling, &
                      nsh_real, &
                      Tmin_id, Tmax_id, lenDay_id, & !inout
@@ -747,12 +743,10 @@ END SUBROUTINE SUEWS_cal_DailyState
    ! END SUBROUTINE update_DailyState_End
 
    SUBROUTINE update_DailyState_Day( &
-      BaseTMethod, &
       DayofWeek_id, &
       avkdn, & !input
       Tair, &
       Precip, &
-      BaseT_HC, &
       BaseT_Heating, BaseT_Cooling, &
       nsh_real, &
       Tmin_id, Tmax_id, lenDay_id, & !inout
@@ -760,13 +754,11 @@ SUBROUTINE update_DailyState_Day( &
       ! use time, only: id, id_prev_t
       IMPLICIT NONE
 
-      INTEGER, INTENT(IN) :: BaseTMethod
       INTEGER, DIMENSION(3), INTENT(in) :: DayofWeek_id
 
       REAL(KIND(1D0)), INTENT(IN) :: avkdn
       REAL(KIND(1D0)), INTENT(IN) :: Tair ! Ambient air temperature [degC], this can be from either forcing or diagnostic
       REAL(KIND(1D0)), INTENT(IN) :: Precip
-      REAL(KIND(1D0)), INTENT(IN) :: BaseT_HC
       REAL(KIND(1D0)), DIMENSION(2), INTENT(IN) :: BaseT_Heating
       REAL(KIND(1D0)), DIMENSION(2), INTENT(IN) :: BaseT_Cooling
       REAL(KIND(1D0)), INTENT(IN) :: nsh_real
@@ -794,18 +786,9 @@ SUBROUTINE update_DailyState_Day( &
       iu = 1 !Set to 1=weekday
       IF (DayofWeek_id(1) == 1 .OR. DayofWeek_id(1) == 7) iu = 2 !Set to 2=weekend
 
-      SELECT CASE (BaseTMethod)
-      CASE (1)
-         BaseT_Heating_use = BaseT_HC
-         BaseT_Cooling_use = BaseT_HC
-      CASE (2)
-         BaseT_Heating_use = BaseT_Heating(iu)
-         BaseT_Cooling_use = BaseT_Cooling(iu)
-
-      CASE default
-         CALL ErrorHint(75, "RunControl.nml", -999, -999, -999)
-
-      END SELECT
+      ! Use weekday/weekend-specific base temperatures for heating/cooling degree day calculations
+      BaseT_Heating_use = BaseT_Heating(iu)
+      BaseT_Cooling_use = BaseT_Cooling(iu)
 
       ! Daily min and max temp (these get updated through the day) ---------------------
       Tmin_id = MIN(Tair, Tmin_id) !Daily min T in column 3