diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2016a5b..8aebc41 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,17 @@
 
 ## Unreleased
 
+## [1.3.1] - 2026-08-20
+
+### Fixed
+
+- RAC活用型全館空調の暖房消費電力計算で、ダクトセントラル側の
+  デフロスト補正係数がRACモデル入力に残り、RAC側の能力補正と重複していた
+  責務を修正した。RACモデルには実際に処理した暖房熱量を渡し、外気温・湿度に
+  よる能力・デフロスト補正をRAC側で1回だけ適用する。
+- 地域2・断熱等級5の検証条件を回帰試験へ追加し、Excelとの差異について、
+  Excel側の湿度系列と補正係数処理の確認事項を差分台帳へ記録した。
+
 ## [1.3.0] - 2026-08-14
 
 ### Changed
diff --git a/README.md b/README.md
index ef37101..2eb1a31 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 
 ## 公開Web版
 
-**[Verification Platform Next ver.1.3.0をブラウザで開く](https://verification-platform-next-dnoeszca4a-an.a.run.app/)**
+**[Verification Platform Next ver.1.3.1をブラウザで開く](https://verification-platform-next-dnoeszca4a-an.a.run.app/)**
 
 公開Web版では、インストールせずに入力、計算、結果ファイルの取得を行えます。
 計算は1件ずつ処理するため、混雑時は画面に表示される順番をお待ちください。
@@ -14,7 +14,7 @@
 データはアップロードしないでください。
 
 住宅の省エネルギー性能を検証するための計算エンジン、入力スキーマ、Gradio UIを
-まとめたPythonモノレポです。正式版は **ver.1.3.0** です。
+まとめたPythonモノレポです。正式版は **ver.1.3.1** です。
 
 本リポジトリは、建築研究所が公開する住宅のエネルギー消費性能計算プログラム
 `pyhees`を基礎とし、検証用の入力画面、床下空調などの拡張計算、数値回帰試験を
diff --git a/apps/gradio/pyproject.toml b/apps/gradio/pyproject.toml
index 1e2d582..519de65 100644
--- a/apps/gradio/pyproject.toml
+++ b/apps/gradio/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "poetry.core.masonry.api"
 
 [tool.poetry]
 name = "verification-platform-app"
-version = "1.3.0"
+version = "1.3.1"
 description = "Gradio application for Verification Platform"
 authors = ["iguchi-lab"]
 packages = [{ include = "verification_app", from = "src" }]
diff --git a/docs/RELEASING.md b/docs/RELEASING.md
index 19364c7..40dfe17 100644
--- a/docs/RELEASING.md
+++ b/docs/RELEASING.md
@@ -5,10 +5,10 @@
 Verification Platform Nextは、製品全体を1つの
 [Semantic Versioning](https://semver.org/) で管理します。
 
-- Pythonパッケージ版: `1.3.0`
-- 表示名: `ver.1.3.0`
-- Gitタグ: `v1.3.0`
-- 成果物接尾辞: `_v1.3.0`
+- Pythonパッケージ版: `1.3.1`
+- 表示名: `ver.1.3.1`
+- Gitタグ: `v1.3.1`
+- 成果物接尾辞: `_v1.3.1`
 
 製品版の正本は
 `packages/pyhees-jjj/src/jjjexperiment/release.py`です。ルート、
@@ -23,10 +23,10 @@ Verification Platform Nextは、製品全体を1つの
 成果物名には安定した版接尾辞を付けます。
 
 ```text
-<case_name>_v1.3.0_input.json
-<case_name>_v1.3.0_output1.csv
-<case_name>_v1.3.0_output2.csv
-<case_name>_v1.3.0_manifest.json
+<case_name>_v1.3.1_input.json
+<case_name>_v1.3.1_output1.csv
+<case_name>_v1.3.1_output2.csv
+<case_name>_v1.3.1_manifest.json
 ```
 
 計算が正常終了すると、マニフェストへ次を記録します。
@@ -67,9 +67,9 @@ GitHub Actionsがすべて成功した後、PRをマージし、マージコミ
 ```bash
 git switch main
 git pull --ff-only
-git tag -a v1.3.0 -m "Verification Platform Next ver.1.3.0"
-git push origin v1.3.0
-gh release create v1.3.0 --title "Verification Platform Next ver.1.3.0"
+git tag -a v1.3.1 -m "Verification Platform Next ver.1.3.1"
+git push origin v1.3.1
+gh release create v1.3.1 --title "Verification Platform Next ver.1.3.1"
 ```
 
 GitHub Releaseには`CHANGELOG.md`の該当版、試験結果、既知の制約を記載します。
diff --git a/docs/calculation_differences.md b/docs/calculation_differences.md
index df9b52c..df98c94 100644
--- a/docs/calculation_differences.md
+++ b/docs/calculation_differences.md
@@ -20,7 +20,7 @@ Verification Platform Nextは、建築研究所等の技術的協力のもと公
 | --- | --- |
 | 建研本家 | `BRI-EES-House/pyhees` Ver.3.10、commit `d5224c4a01def00a8421bcd2fcc0d4b4a5b88644` |
 | 旧Verification Platform | Next移行時の基準commit `0f91ba8381df1b4960557b92b39339385cc9009f` |
-| Verification Platform Next | ver.1.3.0、入力仕様 `260812` |
+| Verification Platform Next | ver.1.3.1、入力仕様 `260812` |
 
 建研本家の版は[`packages/pyhees-jjj/UPSTREAM.md`](../packages/pyhees-jjj/UPSTREAM.md)、
 Nextの製品版は[`jjjexperiment/release.py`](../packages/pyhees-jjj/src/jjjexperiment/release.py)
diff --git a/packages/pyhees-jjj/UPSTREAM.md b/packages/pyhees-jjj/UPSTREAM.md
index 920872f..063c8bc 100644
--- a/packages/pyhees-jjj/UPSTREAM.md
+++ b/packages/pyhees-jjj/UPSTREAM.md
@@ -16,7 +16,7 @@
 - upstream commit: `d5224c4a01def00a8421bcd2fcc0d4b4a5b88644`
 - previous upstream commit: `2de59208427e719edacfeffaa47d46e964c4fc63`（Ver.3.9相当）
 - imported fork commit: `0f91ba8381df1b4960557b92b39339385cc9009f`
-- engine version: `_v1.3.0`
+- engine version: `_v1.3.1`
 - legacy form version: `260715`
 
 この値は `regression/phase5/manifest.json` と一致させます。
diff --git a/packages/pyhees-jjj/pyproject.toml b/packages/pyhees-jjj/pyproject.toml
index 7694e32..3452d11 100644
--- a/packages/pyhees-jjj/pyproject.toml
+++ b/packages/pyhees-jjj/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "poetry.core.masonry.api"
 
 [tool.poetry]
 name = "pyhees-jjj"
-version = "1.3.0"
+version = "1.3.1"
 description = "Pyheesの検証用のフォークプロジェクトです"
 homepage = "https://github.com/izumi-system-development/pyhees-jjj"
 authors = ["Pyhees Development Team"]
diff --git a/packages/pyhees-jjj/src/jjjexperiment/release.py b/packages/pyhees-jjj/src/jjjexperiment/release.py
index 3335b3f..144a4f8 100644
--- a/packages/pyhees-jjj/src/jjjexperiment/release.py
+++ b/packages/pyhees-jjj/src/jjjexperiment/release.py
@@ -11,10 +11,10 @@
 from typing import Any, Mapping
 
 
-VERSION = "1.3.0"
-DISPLAY_VERSION = "ver.1.3.0"
-RELEASE_DATE = "2026-08-14"
-ARTIFACT_VERSION = "_v1.3.0"
+VERSION = "1.3.1"
+DISPLAY_VERSION = "ver.1.3.1"
+RELEASE_DATE = "2026-08-20"
+ARTIFACT_VERSION = "_v1.3.1"
 
 UPSTREAM_PYHEES_VERSION = "3.10.0"
 UPSTREAM_PYHEES_COMMIT = "d5224c4a01def00a8421bcd2fcc0d4b4a5b88644"
diff --git a/packages/pyhees-jjj/src/tests/test_release.py b/packages/pyhees-jjj/src/tests/test_release.py
index 5c0b2d2..46f9c63 100644
--- a/packages/pyhees-jjj/src/tests/test_release.py
+++ b/packages/pyhees-jjj/src/tests/test_release.py
@@ -22,7 +22,7 @@ def test_source_commit_prefers_deployment_metadata(monkeypatch):
 def test_write_artifact_manifest_records_release_and_input(tmp_path, monkeypatch):
     monkeypatch.setenv("VERIFICATION_SOURCE_COMMIT", "0123456789abcdef")
     input_data = {"case_name": "case", "region": 6}
-    path = tmp_path / "case_v1.3.0_manifest.json"
+    path = tmp_path / "case_v1.3.1_manifest.json"
 
     release.write_artifact_manifest(path, input_data)
 
@@ -30,10 +30,10 @@ def test_write_artifact_manifest_records_release_and_input(tmp_path, monkeypatch
     assert manifest == {
         "schema_version": 1,
         "product": "Verification Platform Next",
-        "version": "1.3.0",
-        "display_version": "ver.1.3.0",
-        "release_date": "2026-08-14",
-        "artifact_version": "_v1.3.0",
+        "version": "1.3.1",
+        "display_version": "ver.1.3.1",
+        "release_date": "2026-08-20",
+        "artifact_version": "_v1.3.1",
         "source_commit": "0123456789abcdef",
         "upstream_pyhees_version": "3.10.0",
         "upstream_pyhees_commit": "d5224c4a01def00a8421bcd2fcc0d4b4a5b88644",
@@ -82,7 +82,7 @@ def test_calc_writes_manifest_only_after_success(tmp_path, monkeypatch):
 
     assert actual is result
     assert json.loads(
-        (tmp_path / "release-case_v1.3.0_input.json").read_text(encoding="utf-8")
+        (tmp_path / "release-case_v1.3.1_input.json").read_text(encoding="utf-8")
     ) == input_data
     assert events == [
         ("constants", input_data),
@@ -90,7 +90,7 @@ def test_calc_writes_manifest_only_after_success(tmp_path, monkeypatch):
         ("calculate", experiment_main.calc_main),
         (
             "manifest",
-            Path("release-case_v1.3.0_manifest.json"),
+            Path("release-case_v1.3.1_manifest.json"),
             input_data,
         ),
     ]
diff --git a/packages/verification-core/pyproject.toml b/packages/verification-core/pyproject.toml
index 4617d95..7decdfc 100644
--- a/packages/verification-core/pyproject.toml
+++ b/packages/verification-core/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "poetry.core.masonry.api"
 
 [tool.poetry]
 name = "verification-core"
-version = "1.3.0"
+version = "1.3.1"
 description = "Canonical input schema and shared contracts for Verification Platform"
 authors = ["iguchi-lab"]
 packages = [{ include = "verification_core", from = "src" }]
diff --git a/pyproject.toml b/pyproject.toml
index 4386548..4a3afe9 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "verification-platform-next"
-version = "1.3.0"
+version = "1.3.1"
 description = "Monorepo for the Verification Platform engine, schema, and UI"
 authors = ["iguchi-lab"]
 package-mode = false
diff --git a/regression/phase5/manifest.json b/regression/phase5/manifest.json
index 4e24697..e94fab1 100644
--- a/regression/phase5/manifest.json
+++ b/regression/phase5/manifest.json
@@ -2,7 +2,7 @@
   "schema_version": 1,
   "legacy_form_version": "260715",
   "engine_commit": "d5224c4a01def00a8421bcd2fcc0d4b4a5b88644",
-  "engine_version": "_v1.3.0",
+  "engine_version": "_v1.3.1",
   "tolerances": {
     "relative": 1e-09,
     "absolute": 1e-08
diff --git a/tests/test_gradio_app.py b/tests/test_gradio_app.py
index 408afa9..b909c22 100644
--- a/tests/test_gradio_app.py
+++ b/tests/test_gradio_app.py
@@ -59,7 +59,7 @@ def test_gradio_app_builds_all_schema_inputs_and_events() -> None:
     }
 
     assert gradio.__version__.startswith("6.")
-    assert config["title"] == "Verification Platform Next ver.1.3.0"
+    assert config["title"] == "Verification Platform Next ver.1.3.1"
     assert component_types["accordion"] == 8
     assert component_types["number"] == 156
     assert component_types["dropdown"] == 54
diff --git a/tests/test_release_version.py b/tests/test_release_version.py
index 897dcc5..6ba0ed1 100644
--- a/tests/test_release_version.py
+++ b/tests/test_release_version.py
@@ -13,9 +13,9 @@ def _project_version(path: str) -> str:
 
 
 def test_release_version_is_consistent_across_projects():
-    assert release.VERSION == "1.3.0"
-    assert release.DISPLAY_VERSION == "ver.1.3.0"
-    assert release.ARTIFACT_VERSION == "_v1.3.0"
+    assert release.VERSION == "1.3.1"
+    assert release.DISPLAY_VERSION == "ver.1.3.1"
+    assert release.ARTIFACT_VERSION == "_v1.3.1"
     assert {
         _project_version("pyproject.toml"),
         _project_version("packages/verification-core/pyproject.toml"),