diff --git a/assets/js/contact_map_hook.ts b/assets/js/contact_map_hook.ts
index 31809704..036060a6 100644
--- a/assets/js/contact_map_hook.ts
+++ b/assets/js/contact_map_hook.ts
@@ -13,13 +13,13 @@ export const ContactMap = {
   },
 
   initMap(this: ContactMapHook) {
-    const pos1 = JSON.parse(this.el.dataset.pos1!) as { lat: number; lon?: number; lng?: number }
-    const pos2 = JSON.parse(this.el.dataset.pos2!) as { lat: number; lon?: number; lng?: number }
+    const pos1 = JSON.parse(this.el.dataset.pos1!) as { lat: number; lon: number }
+    const pos2 = JSON.parse(this.el.dataset.pos2!) as { lat: number; lon: number }
 
     const lat1 = pos1.lat
-    const lon1 = (pos1.lon || pos1.lng)!
+    const lon1 = pos1.lon
     const lat2 = pos2.lat
-    const lon2 = (pos2.lon || pos2.lng)!
+    const lon2 = pos2.lon
 
     const bounds = L.latLngBounds([[lat1, lon1], [lat2, lon2]])
 
diff --git a/lib/microwaveprop/backtest.ex b/lib/microwaveprop/backtest.ex
index c6f7d94a..e46fbef0 100644
--- a/lib/microwaveprop/backtest.ex
+++ b/lib/microwaveprop/backtest.ex
@@ -384,11 +384,8 @@ defmodule Microwaveprop.Backtest do
 
   defp eval_feature_for_contact(_feature, _contact), do: nil
 
-  # pos1 is sometimes stored with "lon" and sometimes with "lng".
   defp pos_to_latlon(%{"lat" => lat, "lon" => lon}) when is_number(lat) and is_number(lon), do: {lat * 1.0, lon * 1.0}
 
-  defp pos_to_latlon(%{"lat" => lat, "lng" => lon}) when is_number(lat) and is_number(lon), do: {lat * 1.0, lon * 1.0}
-
   defp pos_to_latlon(_), do: nil
 
   # Matched random baseline: pick a random contact, perturb its
diff --git a/lib/microwaveprop/propagation/recalibrator.ex b/lib/microwaveprop/propagation/recalibrator.ex
index 23a0ff81..1a3c2491 100644
--- a/lib/microwaveprop/propagation/recalibrator.ex
+++ b/lib/microwaveprop/propagation/recalibrator.ex
@@ -159,7 +159,7 @@ defmodule Microwaveprop.Propagation.Recalibrator do
 
   defp contact_to_factors(%Contact{pos1: pos, qso_timestamp: ts}) do
     lat = pos["lat"]
-    lon = pos["lon"] || pos["lng"]
+    lon = pos["lon"]
 
     if lat && lon do
       case Weather.find_nearest_hrrr(lat, lon, ts) do
diff --git a/lib/microwaveprop/propagation/scorer.ex b/lib/microwaveprop/propagation/scorer.ex
index b07c6863..c25208e0 100644
--- a/lib/microwaveprop/propagation/scorer.ex
+++ b/lib/microwaveprop/propagation/scorer.ex
@@ -532,7 +532,7 @@ defmodule Microwaveprop.Propagation.Scorer do
        when dewpoints == [], do: nil
 
   defp build_path_conditions({temps, dewpoints, pressures, gradients, bl_depths, pwats}, contact) do
-    lon = Kernel.||(contact.pos1["lon"] || contact.pos1["lng"], -97.0)
+    lon = contact.pos1["lon"] || -97.0
     avg_temp_c = Enum.sum(temps) / length(temps)
     avg_dewpoint_c = Enum.sum(dewpoints) / length(dewpoints)
 
diff --git a/lib/microwaveprop/radio.ex b/lib/microwaveprop/radio.ex
index a09b2eb8..16e1f6d7 100644
--- a/lib/microwaveprop/radio.ex
+++ b/lib/microwaveprop/radio.ex
@@ -77,9 +77,9 @@ defmodule Microwaveprop.Radio do
 
   defp format_map_contact(c) do
     lat1 = c.pos1["lat"]
-    lon1 = c.pos1["lon"] || c.pos1["lng"]
+    lon1 = c.pos1["lon"]
     lat2 = c.pos2["lat"]
-    lon2 = c.pos2["lon"] || c.pos2["lng"]
+    lon2 = c.pos2["lon"]
 
     if lat1 && lon1 && lat2 && lon2 do
       [
@@ -328,7 +328,7 @@ defmodule Microwaveprop.Radio do
 
   def contact_path_points(%{pos1: pos1, pos2: nil}) do
     lat = pos1["lat"]
-    lon = pos1["lon"] || pos1["lng"]
+    lon = pos1["lon"]
     if lat && lon, do: [{lat, lon}], else: []
   end
 
@@ -337,7 +337,7 @@ defmodule Microwaveprop.Radio do
   end
 
   defp extract_latlon(%{"lat" => lat} = pos) when is_number(lat) do
-    lon = pos["lon"] || pos["lng"]
+    lon = pos["lon"]
     if lon, do: {lat, lon}
   end
 
@@ -374,9 +374,9 @@ defmodule Microwaveprop.Radio do
       for contact <- contacts,
           is_nil(contact.distance_km) && contact.pos1 && contact.pos2,
           lat1 = contact.pos1["lat"],
-          lon1 = contact.pos1["lon"] || contact.pos1["lng"],
+          lon1 = contact.pos1["lon"],
           lat2 = contact.pos2["lat"],
-          lon2 = contact.pos2["lon"] || contact.pos2["lng"],
+          lon2 = contact.pos2["lon"],
           lat1 && lon1 && lat2 && lon2 do
         dist = lat1 |> haversine_km(lon1, lat2, lon2) |> round()
         {contact.id, dist}
@@ -451,8 +451,8 @@ defmodule Microwaveprop.Radio do
   end
 
   defp compute_distance(pos1, pos2, _existing_distance) when not is_nil(pos1) and not is_nil(pos2) do
-    lon1 = pos1["lon"] || pos1["lng"]
-    lon2 = pos2["lon"] || pos2["lng"]
+    lon1 = pos1["lon"]
+    lon2 = pos2["lon"]
 
     pos1["lat"]
     |> haversine_km(lon1, pos2["lat"], lon2)
@@ -983,8 +983,8 @@ defmodule Microwaveprop.Radio do
   end
 
   defp compute_distance(pos1, pos2) when not is_nil(pos1) and not is_nil(pos2) do
-    lon1 = pos1["lon"] || pos1["lng"]
-    lon2 = pos2["lon"] || pos2["lng"]
+    lon1 = pos1["lon"]
+    lon2 = pos2["lon"]
     pos1["lat"] |> haversine_km(lon1, pos2["lat"], lon2) |> round() |> Decimal.new()
   end
 
diff --git a/lib/microwaveprop/weather.ex b/lib/microwaveprop/weather.ex
index ecb0c6a3..47748470 100644
--- a/lib/microwaveprop/weather.ex
+++ b/lib/microwaveprop/weather.ex
@@ -788,7 +788,7 @@ defmodule Microwaveprop.Weather do
 
   def hrrr_for_contact(contact) do
     lat = contact.pos1["lat"]
-    lon = contact.pos1["lon"] || contact.pos1["lng"]
+    lon = contact.pos1["lon"]
 
     if lat && lon do
       find_nearest_hrrr(lat, lon, contact.qso_timestamp)
@@ -893,7 +893,7 @@ defmodule Microwaveprop.Weather do
 
   def narr_for_contact(contact) do
     lat = contact.pos1["lat"]
-    lon = contact.pos1["lon"] || contact.pos1["lng"]
+    lon = contact.pos1["lon"]
 
     if lat && lon do
       find_nearest_narr(lat, lon, contact.qso_timestamp)
@@ -1051,7 +1051,7 @@ defmodule Microwaveprop.Weather do
 
   def iemre_for_contact(contact) do
     lat = contact.pos1["lat"]
-    lon = contact.pos1["lon"] || contact.pos1["lng"]
+    lon = contact.pos1["lon"]
 
     if lat && lon do
       find_nearest_iemre(lat, lon, contact.qso_timestamp)
diff --git a/lib/microwaveprop/workers/hrrr_native_grid_worker.ex b/lib/microwaveprop/workers/hrrr_native_grid_worker.ex
index 7ec5cfb6..6c42ae84 100644
--- a/lib/microwaveprop/workers/hrrr_native_grid_worker.ex
+++ b/lib/microwaveprop/workers/hrrr_native_grid_worker.ex
@@ -67,7 +67,7 @@ defmodule Microwaveprop.Workers.HrrrNativeGridWorker do
     |> select([c], c.pos1)
     |> Repo.all()
     |> Enum.flat_map(fn pos ->
-      case {pos["lat"], pos["lon"] || pos["lng"]} do
+      case {pos["lat"], pos["lon"]} do
         {lat, lon} when is_number(lat) and is_number(lon) -> [{snap(lat), snap(lon)}]
         _ -> []
       end
diff --git a/lib/microwaveprop/workers/nexrad_worker.ex b/lib/microwaveprop/workers/nexrad_worker.ex
index 0056dfbe..d569195c 100644
--- a/lib/microwaveprop/workers/nexrad_worker.ex
+++ b/lib/microwaveprop/workers/nexrad_worker.ex
@@ -55,7 +55,7 @@ defmodule Microwaveprop.Workers.NexradWorker do
     |> select([c], c.pos1)
     |> Repo.all()
     |> Enum.flat_map(fn pos ->
-      case {pos["lat"], pos["lon"] || pos["lng"]} do
+      case {pos["lat"], pos["lon"]} do
         {lat, lon} when is_number(lat) and is_number(lon) -> [{snap(lat), snap(lon)}]
         _ -> []
       end
diff --git a/lib/microwaveprop/workers/terrain_profile_worker.ex b/lib/microwaveprop/workers/terrain_profile_worker.ex
index 27cdf845..77406d11 100644
--- a/lib/microwaveprop/workers/terrain_profile_worker.ex
+++ b/lib/microwaveprop/workers/terrain_profile_worker.ex
@@ -30,9 +30,9 @@ defmodule Microwaveprop.Workers.TerrainProfileWorker do
     contact = Radio.get_contact!(contact_id)
 
     with %{"lat" => lat1} <- contact.pos1,
-         lon1 when is_number(lon1) <- contact.pos1["lon"] || contact.pos1["lng"],
+         lon1 when is_number(lon1) <- contact.pos1["lon"],
          %{"lat" => lat2} <- contact.pos2,
-         lon2 when is_number(lon2) <- contact.pos2["lon"] || contact.pos2["lng"] do
+         lon2 when is_number(lon2) <- contact.pos2["lon"] do
       fetch_and_store_profile(contact_id, contact, lat1, lon1, lat2, lon2)
     else
       _ ->
diff --git a/lib/microwaveprop_web/live/contact_live/show.ex b/lib/microwaveprop_web/live/contact_live/show.ex
index 404cd3b1..84e7f8d9 100644
--- a/lib/microwaveprop_web/live/contact_live/show.ex
+++ b/lib/microwaveprop_web/live/contact_live/show.ex
@@ -559,11 +559,11 @@ defmodule MicrowavepropWeb.ContactLive.Show do
 
   defp extract_contact_coords(contact) do
     lat1 = contact.pos1 && contact.pos1["lat"]
-    lon1 = contact.pos1 && (contact.pos1["lon"] || contact.pos1["lng"])
+    lon1 = contact.pos1 && contact.pos1["lon"]
 
     if lat1 && lon1 do
       lat2 = contact.pos2 && contact.pos2["lat"]
-      lon2 = contact.pos2 && (contact.pos2["lon"] || contact.pos2["lng"])
+      lon2 = contact.pos2 && contact.pos2["lon"]
       {:ok, lat1, lon1, lat2, lon2}
     else
       :error
@@ -634,7 +634,7 @@ defmodule MicrowavepropWeb.ContactLive.Show do
 
   defp maybe_enqueue_hrrr(nil, contact) do
     lat = contact.pos1 && contact.pos1["lat"]
-    lon = contact.pos1 && (contact.pos1["lon"] || contact.pos1["lng"])
+    lon = contact.pos1 && contact.pos1["lon"]
 
     if lat && lon && contact.hrrr_status != :queued do
       valid_time = HrrrClient.nearest_hrrr_hour(contact.qso_timestamp)
@@ -668,7 +668,7 @@ defmodule MicrowavepropWeb.ContactLive.Show do
 
   defp maybe_enqueue_narr(nil, %{hrrr_status: :unavailable} = contact) do
     lat = contact.pos1 && contact.pos1["lat"]
-    lon = contact.pos1 && (contact.pos1["lon"] || contact.pos1["lng"])
+    lon = contact.pos1 && contact.pos1["lon"]
     valid_time = NarrClient.snap_to_analysis_hour(contact.qso_timestamp)
 
     if lat && lon && NarrClient.in_coverage?(valid_time) do
@@ -1501,9 +1501,9 @@ defmodule MicrowavepropWeb.ContactLive.Show do
 
   defp compute_elevation_profile(contact, hrrr_path, soundings) do
     with %{"lat" => lat1} <- contact.pos1,
-         lon1 when is_number(lon1) <- contact.pos1["lon"] || contact.pos1["lng"],
+         lon1 when is_number(lon1) <- contact.pos1["lon"],
          %{"lat" => lat2} <- contact.pos2,
-         lon2 when is_number(lon2) <- contact.pos2["lon"] || contact.pos2["lng"],
+         lon2 when is_number(lon2) <- contact.pos2["lon"],
          {:ok, profile} <- safe_fetch_elevation(lat1, lon1, lat2, lon2) do
       freq_ghz = band_to_ghz(contact.band)
       dist_km = haversine_km(lat1, lon1, lat2, lon2)
diff --git a/lib_ml/propagation_analyze.ex b/lib_ml/propagation_analyze.ex
index ba64e799..0ae44517 100644
--- a/lib_ml/propagation_analyze.ex
+++ b/lib_ml/propagation_analyze.ex
@@ -92,18 +92,18 @@ defmodule Mix.Tasks.PropagationAnalyze do
       tp.verdict AS terrain_verdict,
 
       -- Longitude for solar time
-      ((q.pos1->>'lng')::float + (q.pos2->>'lng')::float) / 2.0 AS avg_longitude
+      ((q.pos1->>'lon')::float + (q.pos2->>'lon')::float) / 2.0 AS avg_longitude
 
     FROM qsos q
 
     INNER JOIN hrrr_profiles h1
       ON h1.lat = ROUND((q.pos1->>'lat')::numeric * 8) / 8
-      AND h1.lon = ROUND((q.pos1->>'lng')::numeric * 8) / 8
+      AND h1.lon = ROUND((q.pos1->>'lon')::numeric * 8) / 8
       AND h1.valid_time = date_trunc('hour', q.qso_timestamp)
 
     INNER JOIN hrrr_profiles h2
       ON h2.lat = ROUND((q.pos2->>'lat')::numeric * 8) / 8
-      AND h2.lon = ROUND((q.pos2->>'lng')::numeric * 8) / 8
+      AND h2.lon = ROUND((q.pos2->>'lon')::numeric * 8) / 8
       AND h2.valid_time = date_trunc('hour', q.qso_timestamp)
 
     LEFT JOIN terrain_profiles tp ON tp.qso_id = q.id
diff --git a/notebooks/algorithm_analysis.livemd b/notebooks/algorithm_analysis.livemd
index 5f9d593c..186dac0b 100644
--- a/notebooks/algorithm_analysis.livemd
+++ b/notebooks/algorithm_analysis.livemd
@@ -325,7 +325,7 @@ scored =
         utc_hour: contact.qso_timestamp.hour,
         utc_minute: contact.qso_timestamp.minute,
         month: contact.qso_timestamp.month,
-        longitude: (contact.pos1["lon"] || contact.pos1["lng"]) |> then(&(&1 || -97.0)),
+        longitude: contact.pos1["lon"] || -97.0,
         temp_f: temp_f,
         dewpoint_f: dewpoint_f,
         min_refractivity_gradient: hrrr.min_refractivity_gradient,
diff --git a/priv/repo/import_contacts.exs b/priv/repo/import_contacts.exs
index e557d4ed..4c5e6c9e 100644
--- a/priv/repo/import_contacts.exs
+++ b/priv/repo/import_contacts.exs
@@ -78,7 +78,7 @@ grid_coords =
     fn grid ->
       case Req.get("#{gridmap_base}#{grid}") do
         {:ok, %{status: 200, body: %{"latitude" => lat, "longitude" => lng}}} ->
-          {grid, %{lat: lat, lng: lng}}
+          {grid, %{"lat" => lat, "lon" => lng}}
 
         {:ok, resp} ->
           IO.puts("  Warning: grid #{grid} returned status #{resp.status}")
@@ -108,7 +108,7 @@ defmodule Haversine do
   def distance_km(nil, _), do: nil
   def distance_km(_, nil), do: nil
 
-  def distance_km(%{lat: lat1, lng: lng1}, %{lat: lat2, lng: lng2}) do
+  def distance_km(%{"lat" => lat1, "lon" => lng1}, %{"lat" => lat2, "lon" => lng2}) do
     dlat = deg_to_rad(lat2 - lat1)
     dlng = deg_to_rad(lng2 - lng1)
     lat1_r = deg_to_rad(lat1)
diff --git a/priv/repo/import_weather.exs b/priv/repo/import_weather.exs
index 9c91b9c9..ff2d59ee 100644
--- a/priv/repo/import_weather.exs
+++ b/priv/repo/import_weather.exs
@@ -198,7 +198,7 @@ Enum.with_index(qsos, 1)
   if rem(idx, 500) == 0, do: IO.puts("  Scanned #{idx}/#{total} QSOs")
 
   lat = qso.pos1["lat"] || qso.pos1["latitude"]
-  lon = qso.pos1["lng"] || qso.pos1["lon"] || qso.pos1["longitude"]
+  lon = qso.pos1["lon"] || qso.pos1["longitude"]
 
   if lat && lon do
     # Find nearby ASOS stations (within 150km)
diff --git a/priv/repo/migrations/20260417140525_normalize_pos_lng_to_lon.exs b/priv/repo/migrations/20260417140525_normalize_pos_lng_to_lon.exs
new file mode 100644
index 00000000..1d0c0c23
--- /dev/null
+++ b/priv/repo/migrations/20260417140525_normalize_pos_lng_to_lon.exs
@@ -0,0 +1,27 @@
+defmodule Microwaveprop.Repo.Migrations.NormalizePosLngToLon do
+  use Ecto.Migration
+
+  def up do
+    execute("""
+    UPDATE contacts SET pos1 = jsonb_set(pos1 - 'lng', '{lon}', pos1->'lng')
+     WHERE pos1 ? 'lng'
+    """)
+
+    execute("""
+    UPDATE contacts SET pos2 = jsonb_set(pos2 - 'lng', '{lon}', pos2->'lng')
+     WHERE pos2 ? 'lng'
+    """)
+  end
+
+  def down do
+    execute("""
+    UPDATE contacts SET pos1 = jsonb_set(pos1 - 'lon', '{lng}', pos1->'lon')
+     WHERE pos1 ? 'lon' AND NOT (pos1 ? 'lng')
+    """)
+
+    execute("""
+    UPDATE contacts SET pos2 = jsonb_set(pos2 - 'lon', '{lng}', pos2->'lon')
+     WHERE pos2 ? 'lon' AND NOT (pos2 ? 'lng')
+    """)
+  end
+end
diff --git a/test/microwaveprop/radio/contact_test.exs b/test/microwaveprop/radio/contact_test.exs
index e8dd4731..efa3279f 100644
--- a/test/microwaveprop/radio/contact_test.exs
+++ b/test/microwaveprop/radio/contact_test.exs
@@ -9,8 +9,8 @@ defmodule Microwaveprop.Radio.ContactTest do
     qso_timestamp: ~U[2026-03-28 12:00:00Z],
     grid1: "FN31pr",
     grid2: "EN91jm",
-    pos1: %{lat: 41.714, lng: -72.727},
-    pos2: %{lat: 41.049, lng: -80.166},
+    pos1: %{lat: 41.714, lon: -72.727},
+    pos2: %{lat: 41.049, lon: -80.166},
     mode: "SSB",
     band: Decimal.new("144.2"),
     distance_km: Decimal.new("623.4")
diff --git a/test/microwaveprop/radio_test.exs b/test/microwaveprop/radio_test.exs
index 9dfefae8..75d25c4c 100644
--- a/test/microwaveprop/radio_test.exs
+++ b/test/microwaveprop/radio_test.exs
@@ -382,11 +382,11 @@ defmodule Microwaveprop.RadioTest do
       assert Radio.contact_path_points(contact) == []
     end
 
-    test "handles lng key in position maps" do
+    test "handles lon key in position maps" do
       contact =
         create_contact(%{
-          pos1: %{"lat" => 32.9, "lng" => -97.0},
-          pos2: %{"lat" => 30.3, "lng" => -97.7}
+          pos1: %{"lat" => 32.9, "lon" => -97.0},
+          pos2: %{"lat" => 30.3, "lon" => -97.7}
         })
 
       points = Radio.contact_path_points(contact)
diff --git a/test/microwaveprop/workers/hrrr_native_grid_worker_test.exs b/test/microwaveprop/workers/hrrr_native_grid_worker_test.exs
index 0e34c1ec..526db62b 100644
--- a/test/microwaveprop/workers/hrrr_native_grid_worker_test.exs
+++ b/test/microwaveprop/workers/hrrr_native_grid_worker_test.exs
@@ -52,13 +52,6 @@ defmodule Microwaveprop.Workers.HrrrNativeGridWorkerTest do
       points = HrrrNativeGridWorker.points_of_interest_for_hour(~U[2026-03-28 18:00:00Z])
       assert points == [{32.9, -97.0}]
     end
-
-    test "handles contacts with pos1 stored as 'lng'" do
-      create_contact(%{pos1: %{"lat" => 32.9, "lng" => -97.0}})
-
-      points = HrrrNativeGridWorker.points_of_interest_for_hour(~U[2026-03-28 18:00:00Z])
-      assert points == [{32.9, -97.0}]
-    end
   end
 
   describe "perform/1" do
diff --git a/test/microwaveprop/workers/nexrad_worker_test.exs b/test/microwaveprop/workers/nexrad_worker_test.exs
index bca0a92f..e5057c28 100644
--- a/test/microwaveprop/workers/nexrad_worker_test.exs
+++ b/test/microwaveprop/workers/nexrad_worker_test.exs
@@ -259,23 +259,6 @@ defmodule Microwaveprop.Workers.NexradWorkerTest do
       assert row.lat == 32.9
       assert row.lon == -97.0
     end
-
-    test ~s(accepts legacy pos1 maps that use the "lng" key instead of "lon") do
-      stub_png_success()
-
-      insert_contact!(%{
-        qso_timestamp: ~U[2022-08-20 14:10:00Z],
-        pos1: %{"lat" => 32.9, "lng" => -97.0}
-      })
-
-      args = %{"year" => 2022, "month" => 8, "day" => 20, "hour" => 14, "minute" => 0}
-
-      assert :ok = NexradWorker.perform(%Oban.Job{args: args})
-
-      assert [row] = Repo.all(NexradObservation)
-      assert row.lat == 32.9
-      assert row.lon == -97.0
-    end
   end
 
   describe "unique constraint" do