diff --git a/scheduler.py b/scheduler.py
index 03b8d6d..e81fb38 100644
--- a/scheduler.py
+++ b/scheduler.py
@@ -88,6 +88,18 @@ class Scheduler:
         self.config.resume_rotation()
         self._wake.set()
 
+    def invalidate_screen(self, screen_id: str):
+        """Force the next tick to re-check() this screen instead of reusing
+        its cached state, however much of its poll_interval is left.
+        Without this, a settings change (e.g. weather's forecast_days) sits
+        in config.json immediately but the screen keeps rendering whatever
+        it last fetched under the *old* settings until its own poll_interval
+        happens to elapse -- up to 30 minutes for weather's default."""
+        cache = self._caches.get(screen_id)
+        if cache is not None:
+            cache.checked_at = 0.0
+        self._wake.set()
+
     def get_status(self) -> dict:
         with self._status_lock:
             status = dict(self._status)
diff --git a/web/app.py b/web/app.py
index 54ed337..64fdbd8 100644
--- a/web/app.py
+++ b/web/app.py
@@ -55,6 +55,7 @@ def create_app(config, screens: dict, scheduler) -> Flask:
                 "boost_cover": "boost_cover" in request.form,
                 "grayscale_cover": "grayscale_cover" in request.form,
             })
+            scheduler.invalidate_screen("navidrome")
             return redirect(url_for("settings_navidrome", saved=1))
         return render_template("settings_navidrome.html", settings=config.get_screen_settings("navidrome"))
 
@@ -92,6 +93,7 @@ def create_app(config, screens: dict, scheduler) -> Flask:
                         "update_minutes": update_minutes,
                         **display_toggles,
                     })
+                    scheduler.invalidate_screen("weather")
                     return redirect(url_for("settings_weather", saved=1))
             else:
                 config.update_screen_settings("weather", {
@@ -102,6 +104,7 @@ def create_app(config, screens: dict, scheduler) -> Flask:
                     "update_minutes": update_minutes,
                     **display_toggles,
                 })
+                scheduler.invalidate_screen("weather")
                 return redirect(url_for("settings_weather", saved=1))
 
         return render_template("settings_weather.html", settings=config.get_screen_settings("weather"), error=error)
@@ -131,9 +134,11 @@ def create_app(config, screens: dict, scheduler) -> Flask:
                         "results": results,
                         "update_minutes": update_minutes,
                     })
+                    scheduler.invalidate_screen("departures")
                     return redirect(url_for("settings_departures", found=found["name"]))
             else:
                 config.update_screen_settings("departures", {"results": results, "update_minutes": update_minutes})
+                scheduler.invalidate_screen("departures")
                 return redirect(url_for("settings_departures", saved=1))
 
         return render_template("settings_departures.html", settings=config.get_screen_settings("departures"), error=error)
@@ -188,6 +193,7 @@ def create_app(config, screens: dict, scheduler) -> Flask:
 
             if not error:
                 config.update_screen_settings("journey", updates)
+                scheduler.invalidate_screen("journey")
                 found_parts = [v for k, v in (("origin", origin_query), ("destination", destination_query)) if v]
                 if found_parts:
                     current = config.get_screen_settings("journey")
@@ -236,13 +242,16 @@ def create_app(config, screens: dict, scheduler) -> Flask:
                             "uploaded_filename": dest.name,
                             **common_updates,
                         })
+                        scheduler.invalidate_screen("picture")
                         return redirect(url_for("settings_picture", saved=1))
             elif url:
                 config.update_screen_settings("picture", {"mode": "url", "image_url": url, **common_updates})
+                scheduler.invalidate_screen("picture")
                 return redirect(url_for("settings_picture", saved=1))
             else:
                 # Neither a new upload nor a URL change -- just update fit/boost/grayscale.
                 config.update_screen_settings("picture", common_updates)
+                scheduler.invalidate_screen("picture")
                 return redirect(url_for("settings_picture", saved=1))
 
         return render_template("settings_picture.html", settings=config.get_screen_settings("picture"), error=error)