diff --git a/pyaerocom/aeroval/experiment_output.py b/pyaerocom/aeroval/experiment_output.py
index 7c975b46f..cffdab848 100644
--- a/pyaerocom/aeroval/experiment_output.py
+++ b/pyaerocom/aeroval/experiment_output.py
@@ -21,6 +21,7 @@
 from pyaerocom.aeroval.setupclasses import EvalSetup
 from pyaerocom.aeroval.varinfo_web import VarinfoWeb
 from pyaerocom.exceptions import EntryNotAvailable, VariableDefinitionError
+from pyaerocom.stats.mda8.const import MDA8_INPUT_VARS, MDA8_OUTPUT_VARS
 from pyaerocom.stats.stats import _init_stats_dummy
 from pyaerocom.variable_helpers import get_aliases
 
@@ -698,6 +699,12 @@ def _is_part_of_experiment(self, obs_name, obs_var, mod_name, mod_var) -> bool:
             True if this combination is valid, else False.
 
         """
+
+        # MDA8 is computed on-the-fly ONLY if a MDA8_INPUT_VAR at hourly freq is detected.
+        # Consequently, it is not specified in a config but should be included as part of the experiment.
+        if obs_var in MDA8_OUTPUT_VARS and mod_var in MDA8_OUTPUT_VARS:
+            return True
+
         # get model entry for model name
         try:
             mcfg = self.cfg.model_cfg.get_entry(mod_name)
diff --git a/pyaerocom/aeroval/glob_defaults.py b/pyaerocom/aeroval/glob_defaults.py
index ff3aca270..28c1d87d5 100644
--- a/pyaerocom/aeroval/glob_defaults.py
+++ b/pyaerocom/aeroval/glob_defaults.py
@@ -629,6 +629,7 @@
     vmrso2=["SO2", "3D", "Gas volume mixing ratio"],
     concso4=["SO4", "3D", "Particle concentrations"],
     vmro3=["O3", "3D", "Volume mixing ratios"],
+    vmro3mda8=["O3 (MDA8)", "3D", "Valume mixing ratios"],
     vmro3max=["O3Max", "3D", "Volume mixing ratios"],
     vmrox=["OX", "3D", "Gas volume mixing ratio"],
     concco=["CO", "3D", "Particle concentration"],
diff --git a/pyaerocom/colocation/colocator.py b/pyaerocom/colocation/colocator.py
index c4ac05db9..fcf5e10ec 100644
--- a/pyaerocom/colocation/colocator.py
+++ b/pyaerocom/colocation/colocator.py
@@ -31,7 +31,7 @@
 from pyaerocom.io import ReadCAMS2_83, ReadGridded, ReadUngridded
 from pyaerocom.io.helpers import get_all_supported_ids_ungridded
 from pyaerocom.io.mscw_ctm.reader import ReadMscwCtm
-from pyaerocom.stats.mda8.const import MDA_VARS
+from pyaerocom.stats.mda8.const import MDA8_INPUT_VARS
 from pyaerocom.stats.mda8.mda8 import mda8_colocated_data
 
 from .colocated_data import ColocatedData
@@ -383,17 +383,16 @@ def run(self, var_list: list = None):
                 )  # note this can be ColocatedData or ColocatedDataLists
                 data_out[mod_var][obs_var] = coldata
 
-                if obs_var in MDA_VARS:
-                    mda8 = None
+                if obs_var in MDA8_INPUT_VARS:
                     try:
                         mda8 = mda8_colocated_data(
                             coldata, obs_var=f"{obs_var}mda8", mod_var=f"{mod_var}mda8"
                         )
-                    except ValueError:
-                        logger.warning(
-                            "Tried calculating mda8 for [%s, %s], but failed.", obs_var, mod_var
-                        )
-                    finally:
+                    except ValueError as e:
+                        logger.debug(e)
+                    else:
+                        self._save_coldata(mda8)
+                        logger.info("Successfully calculated mda8 for [%s, %s].", obs_var, mod_var)
                         data_out[f"{mod_var}mda8"][f"{obs_var}mda8"] = mda8
 
                 self._processing_status.append([mod_var, obs_var, 1])
diff --git a/pyaerocom/data/variables.ini b/pyaerocom/data/variables.ini
index 4d1477281..23dd82cb5 100644
--- a/pyaerocom/data/variables.ini
+++ b/pyaerocom/data/variables.ini
@@ -3105,6 +3105,10 @@ unit = ug m-3
 description=Mass concentration of ozone
 unit = ug m-3
 
+[vmro3mda8]
+description=MDA8 of O3 VMR.
+unit = nmol mol-1
+
 [concco]
 description=Mass concentration of organic carbon
 unit = ug m-3
diff --git a/pyaerocom/stats/mda8/const.py b/pyaerocom/stats/mda8/const.py
index 8c32ac409..e0e6dc2fd 100644
--- a/pyaerocom/stats/mda8/const.py
+++ b/pyaerocom/stats/mda8/const.py
@@ -1,2 +1,3 @@
 # Variable names for which mda8 values are to be calculated.
-MDA_VARS = ("conco3", "vmro3")
+MDA8_INPUT_VARS = ("conco3", "vmro3")
+MDA8_OUTPUT_VARS = ("vmro3mda8",)
diff --git a/pyaerocom/stats/mda8/mda8.py b/pyaerocom/stats/mda8/mda8.py
index 471708fae..c7a63fd9b 100644
--- a/pyaerocom/stats/mda8/mda8.py
+++ b/pyaerocom/stats/mda8/mda8.py
@@ -1,8 +1,12 @@
+import logging
+
 import numpy as np
 import xarray as xr
 
 from pyaerocom.colocation.colocated_data import ColocatedData
 
+logger = logging.getLogger(__name__)
+
 
 def min_periods_max(x: np.ndarray, /, min_periods=1) -> float:
     """Calculates the max of a 1-dimensional array, returning
@@ -44,6 +48,7 @@ def mda8_colocated_data(coldat: ColocatedData, /, obs_var: str, mod_var: str) ->
 
     cd = ColocatedData(_calc_mda8(coldat.data))
     cd.data.attrs["var_name"] = [obs_var, mod_var]
+    cd.metadata["var_name_input"] = [obs_var, mod_var]
     return cd