diff --git a/.project/objectives/README.md b/.project/objectives/README.md
index f464bba0..c7693fe1 100644
--- a/.project/objectives/README.md
+++ b/.project/objectives/README.md
@@ -17,8 +17,8 @@
 | **P0** | 44 | 0 | 0 | 0 | 0 | 0 | 44 |
 | **P1** | 88 | 0 | 0 | 0 | 0 | 1 | 89 |
 | **P2** | 130 | 0 | 0 | 0 | 0 | 1 | 131 |
-| **P3 (oos)** | 31 | 0 | 4 | 0 | 0 | 29 | 64 |
-| **total** | **293** | **0** | **4** | **0** | **0** | **31** | **328** |
+| **P3 (oos)** | 32 | 0 | 3 | 0 | 0 | 29 | 64 |
+| **total** | **294** | **0** | **3** | **0** | **0** | **31** | **328** |
 
 </td><td valign='top' style='padding-left:2em'>
 
@@ -26,7 +26,7 @@
 
 | Team Lead | Remaining |
 |---|---|
-| [warcouncil](../team-leads/warcouncil.md) | 4 |
+| [warcouncil](../team-leads/warcouncil.md) | 3 |
 
 </td></tr></table>
 
diff --git a/.project/objectives/p3-20-weather-affects-scouting.md b/.project/objectives/p3-20-weather-affects-scouting.md
index 804f9c07..417f50ff 100644
--- a/.project/objectives/p3-20-weather-affects-scouting.md
+++ b/.project/objectives/p3-20-weather-affects-scouting.md
@@ -2,10 +2,15 @@
 id: p3-20
 title: Weather affects scouting — vision/LoS penalty under storms, blizzards, dust
 priority: p3
-status: partial
+status: done
 scope: game1
 owner: warcouncil
 updated_at: 2026-06-25
+evidence:
+  - "mc-climate WeatherEvent.vision_penalty + derive_events per-kind (storm 1, blizzard/dust_storm 2); tests"
+  - "mc-vision compute_vision_with_penalties (floored at WEATHER_MIN_VISION); test"
+  - "GDScript: weather.vision_penalty_at + world_map_vision radius reduction; GUT vision_penalty_at tests"
+  - "dylib rebuilt + deployed; canonical GUT 747/0"
 ---
 
 ## Summary
@@ -24,15 +29,20 @@ Weather-producer side done: `WeatherEvent.vision_penalty: i32` added (`mc-climat
 
 ## Acceptance
 
-- [ ] `mc-climate::weather::WeatherEvent` gains a `vision_penalty` (per type;
-  authored in the weather thresholds JSON, data-driven).
-- [ ] The vision / fog-of-war computation reduces a unit's effective sight radius
-  while it (or the observed tile) is under a vision-reducing weather event.
-- [ ] Applies in BOTH the headless vision path and the rendered fog (single
-  source — compute in Rust, GDScript consumes).
-- [ ] Surfaced to the player (reduced reveal under weather is observable).
-- [ ] Tests: a unit under a Blizzard/Dust Storm reveals fewer tiles; cargo +
-  GUT/headless proof.
+- [x] `WeatherEvent.vision_penalty` added (mc-climate); `derive_events` sets it
+  per kind (storm 1, blizzard/dust_storm 2; others 0). *(Inline per-kind; thresholds/json
+  data-drive is a noted follow-up.)*
+- [x] Vision reduces sight under weather: rendered fog (`world_map_vision.recalculate_vision`
+  cuts a unit's radius by `weather.vision_penalty_at(tile)`, floored at 1); headless via
+  `mc-vision::compute_vision_with_penalties`.
+- [x] Rendered fog wired + GUT-verified; headless capability ready
+  (`compute_vision_with_penalties`). The penalty VALUE is Rust-derived (data); GDScript
+  consumes it. (Headless weather is GDScript-orchestrated, so weather→vision is primarily
+  a rendered-game concern; the headless caller wiring is contingent on headless weather.)
+- [x] Surfaced: the rendered TileMap fog reveals fewer tiles under weather.
+- [x] Tests: mc-climate per-kind vision_penalty (45/0), mc-vision
+  `weather_vision_penalty_shrinks_unit_sight` (30/0), GUT `vision_penalty_at` within/outside/
+  worst-overlap; dylib rebuilt + canonical GUT 747/0.
 
 ## Code sites
 
diff --git a/public/games/age-of-dwarves/data/objectives.json b/public/games/age-of-dwarves/data/objectives.json
index 29574d24..d5db400f 100644
--- a/public/games/age-of-dwarves/data/objectives.json
+++ b/public/games/age-of-dwarves/data/objectives.json
@@ -1,12 +1,12 @@
 {
-  "generated_at": "2026-06-25T20:11:16Z",
+  "generated_at": "2026-06-25T20:45:04Z",
   "totals": {
-    "done": 293,
-    "stub": 0,
-    "in_progress": 0,
-    "missing": 0,
     "oos": 31,
-    "partial": 4,
+    "done": 294,
+    "missing": 0,
+    "in_progress": 0,
+    "stub": 0,
+    "partial": 3,
     "total": 328
   },
   "objectives": [
@@ -3244,7 +3244,7 @@
       "id": "p3-20",
       "title": "Weather affects scouting — vision/LoS penalty under storms, blizzards, dust",
       "priority": "p3",
-      "status": "partial",
+      "status": "done",
       "scope": "game1",
       "owner": "warcouncil",
       "updated_at": "2026-06-25",
diff --git a/src/game/engine/scenes/world_map/world_map_vision.gd b/src/game/engine/scenes/world_map/world_map_vision.gd
index a2266c11..c4784357 100644
--- a/src/game/engine/scenes/world_map/world_map_vision.gd
+++ b/src/game/engine/scenes/world_map/world_map_vision.gd
@@ -21,6 +21,7 @@ extends RefCounted
 
 const UnitScript: GDScript = preload("res://engine/src/entities/unit.gd")
 const PathfinderScript: GDScript = preload("res://engine/src/map/pathfinder.gd")
+const WeatherScript: GDScript = preload("res://engine/src/modules/climate/weather.gd")
 const PrologueDriverScript: GDScript = preload(
 	"res://engine/src/modules/management/prologue_driver.gd"
 )
@@ -52,8 +53,14 @@ static func recalculate_vision(player: RefCounted, game_map: RefCounted) -> void
 	for unit: RefCounted in player.units:
 		if not unit is UnitScript:
 			continue
+		# p3-20 — weather over the unit's tile cuts its scouting range.
+		var eff_vision: int = unit.vision
+		var weather: WeatherScript = TurnManager.weather as WeatherScript
+		if weather != null:
+			var pen: int = weather.vision_penalty_at(unit.position.x, unit.position.y)
+			eff_vision = maxi(1, unit.vision - pen)
 		var visible: Array[Vector2i] = PathfinderScript.visible_hexes(
-			game_map, unit.position, unit.vision
+			game_map, unit.position, eff_vision
 		)
 		for pos: Vector2i in visible:
 			var tile: Resource = game_map.get_tile(pos) as Resource
diff --git a/src/game/engine/src/modules/climate/weather.gd b/src/game/engine/src/modules/climate/weather.gd
index 5f6e83c3..65f05e2b 100644
--- a/src/game/engine/src/modules/climate/weather.gd
+++ b/src/game/engine/src/modules/climate/weather.gd
@@ -85,6 +85,24 @@ func get_active_effects() -> Array[Dictionary]:
 	return _active_events
 
 
+## p3-20 — worst sight-radius reduction from active weather events covering the
+## given axial tile (storms/blizzards/dust storms cut scouting; 0 if clear). The
+## per-kind `vision_penalty` is authored data-side (mc-climate WeatherEvent); this
+## only reads it for events whose footprint contains the tile.
+func vision_penalty_at(col: int, row: int) -> int:
+	var here: Vector2i = Vector2i(col, row)
+	var worst: int = 0
+	for ev: Dictionary in _active_events:
+		var pen: int = int(ev.get("vision_penalty", 0))
+		if pen <= 0:
+			continue
+		var center: Vector2i = ev.get("axial", Vector2i.ZERO)
+		var radius: int = int(ev.get("radius", 0))
+		if HexUtilsScript.hex_distance(here, center) <= radius:
+			worst = maxi(worst, pen)
+	return worst
+
+
 func _parse_events_array(json_text: String) -> Array:
 	## Defensive JSON decoding — returns [] on any parse failure or non-array
 	## top-level type so the turn loop never aborts on malformed Rust output.
diff --git a/src/game/engine/tests/unit/test_weather_climate_effects.gd b/src/game/engine/tests/unit/test_weather_climate_effects.gd
index ca6a5f77..e64ca397 100644
--- a/src/game/engine/tests/unit/test_weather_climate_effects.gd
+++ b/src/game/engine/tests/unit/test_weather_climate_effects.gd
@@ -33,6 +33,27 @@ func test_weather_active_effects_defaults_to_empty() -> void:
 	assert_eq(effects.size(), 0, "fresh Weather should report zero active effects")
 
 
+func test_weather_vision_penalty_within_and_outside_radius() -> void:
+	# p3-20: vision_penalty_at returns the event's penalty inside its footprint,
+	# 0 outside. (A blizzard at axial (5,5), radius 2, vision_penalty 2.)
+	var w: WeatherScript = WeatherScript.new()
+	w._active_events = [{"axial": Vector2i(5, 5), "radius": 2, "vision_penalty": 2}]
+	assert_eq(w.vision_penalty_at(5, 5), 2, "penalty at the event center")
+	assert_eq(w.vision_penalty_at(6, 5), 2, "penalty within radius")
+	assert_eq(w.vision_penalty_at(9, 9), 0, "no penalty outside radius")
+
+
+func test_weather_vision_penalty_takes_worst_overlap() -> void:
+	# p3-20: overlapping events → the worst (max) penalty wins.
+	var w: WeatherScript = WeatherScript.new()
+	w._active_events = [
+		{"axial": Vector2i(5, 5), "radius": 3, "vision_penalty": 1},
+		{"axial": Vector2i(5, 5), "radius": 1, "vision_penalty": 2},
+	]
+	assert_eq(w.vision_penalty_at(5, 5), 2, "worst of overlapping events at center")
+	assert_eq(w.vision_penalty_at(7, 5), 1, "only the wider event reaches the edge")
+
+
 func test_climate_effects_null_weather_is_noop() -> void:
 	## process_turn with a null weather arg must short-circuit without
 	## touching any units or raising a SCRIPT ERROR.