diff --git a/homeassistant/components/open_meteo/weather.py b/homeassistant/components/open_meteo/weather.py
index a2be81f0928..efaee28a448 100644
--- a/homeassistant/components/open_meteo/weather.py
+++ b/homeassistant/components/open_meteo/weather.py
@@ -156,6 +156,8 @@ class OpenMeteoWeatherEntity(
 
         hourly = self.coordinator.data.hourly
         for index, datetime in enumerate(self.coordinator.data.hourly.time):
+            if datetime.tzinfo is None:
+                datetime = datetime.replace(tzinfo=dt_util.UTC)
             if dt_util.as_utc(datetime) < today:
                 continue