diff --git a/backend/weather.py b/backend/weather.py
index cdf09d8..9bec358 100644
--- a/backend/weather.py
+++ b/backend/weather.py
@@ -239,7 +239,9 @@ def _wind_dir(deg: float) -> str:
 
 
 def _asphalt_temp(air_max: float, uv_max: float) -> tuple[float, str]:
-    bonus = min(uv_max * 3.0, 30.0)
+    # UV-Bonus skaliert mit Temperatur: unter 10°C kaum Aufheizung, ab 30°C voll
+    t_factor = max(0.0, min(1.0, (air_max - 5) / 25))
+    bonus = min(uv_max * 3.0 * t_factor, 30.0)
     asphalt = air_max + bonus
     if asphalt <= 30:
         warn = 'safe'