Weather changes on time; repeat rolls lengthen the spell

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_game.py

@@ -302,6 +302,7 @@ class CityTest(unittest.TestCase):
         world = world_with()
         city = world["city"]
         city["stockpile"] = {"bread": 5}
+        world["next_fortune_at"] = None  # no lucky wagon of bread
         game.tick(world, T0 + 4 * game.DAY, random.Random(1))
         self.assertTrue(city["starving"])
         self.assertNotIn("bread", city["stockpile"])
@@ -953,6 +954,18 @@ class HappeningsTest(unittest.TestCase):
         self.assertEqual(game.season(self.world, T0 + 8 * game.DAY)["name"], "Summer")
         self.assertEqual(game.season(self.world, T0 + 22 * game.DAY)["name"], "Winter")
 
+    def test_weather_changes_on_time_and_always_to_something_new(self):
+        weather = self.city["weather"]
+        weather.update(kind="rain", next="clear", until=T0 + 10 * 60)
+        self.city["last_tick"] = T0
+        game.tick(self.world, T0 + 11 * 60, self.rng)  # well inside the hour
+        self.assertEqual(weather["kind"], "clear")
+        for _ in range(50):
+            spell = weather["until"]
+            game.tick(self.world, spell, self.rng)
+            self.assertNotEqual(weather["next"], weather["kind"])
+            self.assertGreater(weather["until"], spell)
+
     def test_days_count_midnights_not_24_hour_stretches(self):
         from datetime import datetime
         late = datetime(2026, 10, 18, 23, 0).timestamp()