diff --git a/.project/objectives/p3-26-complete-headless-simulator.md b/.project/objectives/p3-26-complete-headless-simulator.md
index 6d5e26a0..216d42fe 100644
--- a/.project/objectives/p3-26-complete-headless-simulator.md
+++ b/.project/objectives/p3-26-complete-headless-simulator.md
@@ -25,7 +25,7 @@ expansion, tech/science, fauna encounters, combat/siege, diplomacy. Verified liv
 
 ## Acceptance (sequenced; each gap closed in bounded, cargo+e2e-verified increments)
 
-- [ ] **Gap 1 — Climate / environment runtime.** Port the live per-turn chain
+- [~] **Gap 1 — Climate / environment runtime.** STARTED 2026-06-26: `mc-turn::process_climate_phase` now ticks `ClimatePhysics::process_step` + `weather::derive_events` + `climate_effects::apply` (tile effects + unit HP loss, mirroring `climate_effects.gd`: `hp=max(0,hp-loss)`) each round on `state.grid`. Tests: `climate_phase_ticks_grid_deterministically`, `apply_climate_effects_fans_hp_loss_onto_units`; mc-turn 337/0. **Remaining:** `marine_harvest` (ocean_dead_fraction feeding climate). ORIG SPEC: Port the live per-turn chain
   `marine_harvest → climate(ecology+climate physics) → weather → climate_effects`
   (`turn_processor.gd::_process_climate`) into a `mc-turn` climate phase. The PHYSICS is
   already Rust (`mc-climate`: `physics.process_step`, `climate_effects::apply`,
diff --git a/public/games/age-of-dwarves/data/objectives.json b/public/games/age-of-dwarves/data/objectives.json
index 99613431..b6cd4d77 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": "2026-06-26T12:25:01Z",
+  "generated_at": "2026-06-26T14:25:33Z",
   "totals": {
-    "missing": 0,
-    "partial": 3,
-    "oos": 31,
     "in_progress": 0,
+    "partial": 3,
     "stub": 0,
     "done": 296,
+    "oos": 31,
+    "missing": 0,
     "total": 330
   },
   "objectives": [
diff --git a/src/simulator/Cargo.lock b/src/simulator/Cargo.lock
index 5f3712f7..7dd32c99 100644
--- a/src/simulator/Cargo.lock
+++ b/src/simulator/Cargo.lock
@@ -2043,6 +2043,7 @@ dependencies = [
  "mc-ai",
  "mc-city",
  "mc-civics",
+ "mc-climate",
  "mc-combat",
  "mc-comms",
  "mc-core",
diff --git a/src/simulator/crates/mc-turn/src/processor.rs b/src/simulator/crates/mc-turn/src/processor.rs
index d90576eb..485d3a22 100644
--- a/src/simulator/crates/mc-turn/src/processor.rs
+++ b/src/simulator/crates/mc-turn/src/processor.rs
@@ -1023,10 +1023,70 @@ impl TurnProcessor {
     fn process_climate_phase(&self, state: &mut GameState) {
         let turn = state.turn;
         let seed = state.map_seed;
-        if let Some(grid) = state.grid.as_mut() {
+        if state.grid.is_none() {
+            return;
+        }
+        // 1. Climate physics: evolve temperature / aerosol / precipitation on the grid.
+        {
+            let grid = state.grid.as_mut().unwrap();
             let mut climate = mc_climate::physics::ClimatePhysics::new("{}", "[]", "{}");
             climate.process_step(grid, turn, seed, 1.0);
         }
+        // 2. Derive this round's weather events (storms / heat waves / blizzards) from
+        //    the updated grid. Default thresholds match the live `GdWeatherPhysics`.
+        let events = mc_climate::weather::derive_events(
+            state.grid.as_ref().unwrap(),
+            &mc_climate::weather::WeatherThresholds::default(),
+            turn as i32,
+            seed,
+        );
+        if events.is_empty() {
+            return;
+        }
+        // 3. Apply tile + unit effects from this round's weather.
+        Self::apply_climate_effects(state, &events);
+    }
+
+    /// p3-26 gap 1: apply a round's weather events to the grid + fan per-unit HP loss
+    /// onto the units. Split out of `process_climate_phase` so the unit-effect wiring is
+    /// testable without the physics/RNG. Mirrors `climate_effects.gd`: `hp = max(0, hp -
+    /// hp_loss)`; `movement_penalty` is surfaced in the result but not applied to units
+    /// (the live game doesn't apply it either).
+    fn apply_climate_effects(
+        state: &mut GameState,
+        events: &[mc_climate::weather::WeatherEvent],
+    ) {
+        if events.is_empty() || state.grid.is_none() {
+            return;
+        }
+        let units: Vec<mc_climate::climate_effects::UnitInput> = state
+            .players
+            .iter()
+            .flat_map(|p| p.units.iter())
+            .map(|u| mc_climate::climate_effects::UnitInput {
+                id: u.id as i64,
+                q: u.col,
+                r: u.row,
+            })
+            .collect();
+        let result =
+            mc_climate::climate_effects::apply(state.grid.as_mut().unwrap(), events, &units);
+        if result.unit_effects.is_empty() {
+            return;
+        }
+        let losses: std::collections::HashMap<i64, i32> = result
+            .unit_effects
+            .iter()
+            .filter(|e| e.hp_loss > 0)
+            .map(|e| (e.id, e.hp_loss))
+            .collect();
+        for p in &mut state.players {
+            for u in &mut p.units {
+                if let Some(&loss) = losses.get(&(u.id as i64)) {
+                    u.hp = (u.hp - loss).max(0);
+                }
+            }
+        }
     }
 
     fn process_culture(&self, state: &mut GameState, pi: usize) {
@@ -5854,6 +5914,56 @@ mod tests {
         processor.process_climate_phase(&mut empty);
     }
 
+    #[test]
+    fn apply_climate_effects_fans_hp_loss_onto_units() {
+        // p3-26 gap 1: a heat-wave event in a unit's radius reduces that unit's HP via
+        // the headless climate wiring; a unit outside the radius is untouched.
+        // Deterministic — a hand-built event, no physics/RNG.
+        use mc_core::grid::GridState;
+        let mut state = GameState::default();
+        state.grid = Some(GridState::new(12, 12));
+        let mut p = crate::game_state::PlayerState::default();
+        p.player_index = 0;
+        p.units.push(MapUnit {
+            id: 7,
+            col: 5,
+            row: 5,
+            hp: 60,
+            max_hp: 60,
+            unit_id: "warrior".into(),
+            ..MapUnit::default()
+        });
+        p.units.push(MapUnit {
+            id: 8,
+            col: 0,
+            row: 0,
+            hp: 60,
+            max_hp: 60,
+            unit_id: "warrior".into(),
+            ..MapUnit::default()
+        });
+        state.players.push(p);
+
+        let event = mc_climate::weather::WeatherEvent {
+            kind: "heat_wave".into(),
+            col: 5,
+            row: 5,
+            radius: 2,
+            severity: 1.0,
+            moisture_delta: -0.02,
+            temperature_delta: 0.02,
+            movement_penalty: 0.0,
+            unit_damage: 4,
+            vision_penalty: 0,
+        };
+        TurnProcessor::apply_climate_effects(&mut state, &[event]);
+
+        let u7 = state.players[0].units.iter().find(|u| u.id == 7).unwrap();
+        let u8 = state.players[0].units.iter().find(|u| u.id == 8).unwrap();
+        assert!(u7.hp < 60, "unit in the heat-wave radius must lose HP (got {})", u7.hp);
+        assert_eq!(u8.hp, 60, "unit outside the radius is unharmed");
+    }
+
     #[test]
     fn processor_is_deterministic() {
         use mc_core::grid::GridState;