diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index ae9d110fe..79b070190 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -16,7 +16,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v3
         with:
-          python-version: "3.9"
+          python-version: "3.10"
       - run: pip install cram nextstrain-augur
       - run: cram --shell=/bin/bash tests/sanitize-metadata.t
 
diff --git a/.github/workflows/rebuild-100k.yml b/.github/workflows/rebuild-100k.yml
index 529a3526d..4d695134e 100644
--- a/.github/workflows/rebuild-100k.yml
+++ b/.github/workflows/rebuild-100k.yml
@@ -9,9 +9,9 @@ on:
 
 jobs:
   gisaid:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - uses: nextstrain/.github/actions/setup-nextstrain-cli@master
       with:
diff --git a/.github/workflows/rebuild-country.yml b/.github/workflows/rebuild-country.yml
index ac74b0e29..365f2c6ad 100644
--- a/.github/workflows/rebuild-country.yml
+++ b/.github/workflows/rebuild-country.yml
@@ -23,13 +23,13 @@ env:
 
 jobs:
   gisaid:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
     - uses: nextstrain/.github/actions/setup-nextstrain-cli@master
       with:
-        python-version: "3.9"
+        python-version: "3.10"
 
     - name: Launch build
       run: |
diff --git a/.github/workflows/rebuild-gisaid-21L.yml b/.github/workflows/rebuild-gisaid-21L.yml
index e2146c682..156d51d38 100644
--- a/.github/workflows/rebuild-gisaid-21L.yml
+++ b/.github/workflows/rebuild-gisaid-21L.yml
@@ -23,13 +23,13 @@ env:
 
 jobs:
   gisaid-21L:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
     - uses: nextstrain/.github/actions/setup-nextstrain-cli@master
       with:
-        python-version: "3.9"
+        python-version: "3.10"
 
     - name: Launch build
       run: |
diff --git a/.github/workflows/rebuild-gisaid.yml b/.github/workflows/rebuild-gisaid.yml
index 98d276533..d7ab4d570 100644
--- a/.github/workflows/rebuild-gisaid.yml
+++ b/.github/workflows/rebuild-gisaid.yml
@@ -23,13 +23,13 @@ env:
 
 jobs:
   gisaid:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
     - uses: nextstrain/.github/actions/setup-nextstrain-cli@master
       with:
-        python-version: "3.9"
+        python-version: "3.10"
 
     - name: Launch build
       run: |
diff --git a/.github/workflows/rebuild-open.yml b/.github/workflows/rebuild-open.yml
index 8059690de..fb17b98e9 100644
--- a/.github/workflows/rebuild-open.yml
+++ b/.github/workflows/rebuild-open.yml
@@ -24,13 +24,13 @@ env:
 
 jobs:
   open:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
     - uses: nextstrain/.github/actions/setup-nextstrain-cli@master
       with:
-        python-version: "3.9"
+        python-version: "3.10"
 
     - name: Launch build
       run: |
diff --git a/.github/workflows/revert.yml b/.github/workflows/revert.yml
index e655c41ee..52709cac2 100644
--- a/.github/workflows/revert.yml
+++ b/.github/workflows/revert.yml
@@ -22,13 +22,13 @@ env:
 
 jobs:
   revert:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
     - uses: nextstrain/.github/actions/setup-nextstrain-cli@master
       with:
-        python-version: "3.9"
+        python-version: "3.10"
 
     - name: Revert build
       run: |
diff --git a/.github/workflows/sync-redirects.yaml b/.github/workflows/sync-redirects.yaml
index ed3043c61..56ee83e9a 100644
--- a/.github/workflows/sync-redirects.yaml
+++ b/.github/workflows/sync-redirects.yaml
@@ -17,7 +17,7 @@ jobs:
     if: github.repository_owner == 'nextstrain'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: actions/setup-python@v4
 
       - name: Upgrade Python toolchain