diff --git a/doc/release_notes.md b/doc/release_notes.md
index a57130d3c1..56787b911e 100644
--- a/doc/release_notes.md
+++ b/doc/release_notes.md
@@ -49,6 +49,7 @@
 
 - doc: Disable root TOC entries in order to declutter the table of contents for the rules overview ([2216](https://github.com/PyPSA/pypsa-eur/pull/2216)).
 
+* fix: Ensure `inflow_t` is always defined in `attach_hydro`, resolving a pylint use-before-assignment issue ([#2224](https://github.com/PyPSA/pypsa-eur/pull/2224)).
 * Add missing regex anchor with `re.fullmatch` to `create_zenodo_deposition_cli` utils script ([#2225](https://github.com/PyPSA/pypsa-eur/pull/2225)).
 
 ## PyPSA-Eur v2026.02.0 (18th February 2026)
diff --git a/scripts/add_electricity.py b/scripts/add_electricity.py
index 492c50e934..e7d824eb62 100755
--- a/scripts/add_electricity.py
+++ b/scripts/add_electricity.py
@@ -770,6 +770,7 @@ def attach_hydro(
     country = ppl["bus"].map(n.buses.country).rename("country")
 
     inflow_idx = ror.index.union(hydro.index)
+    inflow_t = pd.DataFrame()
     if not inflow_idx.empty:
         dist_key = ppl.loc[inflow_idx, "p_nom"].groupby(country).transform(normed)
 
@@ -803,7 +804,7 @@ def attach_hydro(
             capital_cost=costs.at["ror", "capital_cost"],
             weight=ror["p_nom"],
             p_max_pu=(
-                inflow_t[ror.index]  # pylint: disable=E0606
+                inflow_t[ror.index]
                 .divide(ror["p_nom"], axis=1)
                 .where(lambda df: df <= 1.0, other=1.0)
             ),