Python 3.10 reached end of life on October 1, 2026, according to the Python developer guide: the core team no longer ships security fixes for the 3.10 branch. On AWS, the python3.10 Lambda runtime follows on October 31, 2026, when it is deprecated; function creation is blocked from July 29, 2027 and updates from August 31, 2027.

AWS publishes calendar dates only, with no time of day or time zone.

Python 3.10 end of life: the upstream dates

Python 3.10.0 was released on October 4, 2021. Under the five-year support cycle used for CPython branches, 3.10 spent its final years in security-only mode, and the developer guide now lists it under unsupported versions with an end-of-life date of 2026-10-01.

The remaining branches, as of October 2026:

  • Python 3.11 - security fixes only, end of life scheduled for October 2027
  • Python 3.12 - security fixes only, end of life scheduled for October 2028
  • Python 3.13 - security fixes only, end of life scheduled for October 2029
  • Python 3.14 - bugfix releases, end of life scheduled for October 2030
  • Python 3.15 - released October 9, 2026, end of life scheduled for October 2031

Moving from 3.10 to 3.11 buys only one year. For most teams, 3.12 or 3.13 is the more practical target.

AWS Lambda python3.10 deprecation timeline

The Lambda runtimes page lists three dates for python3.10, which runs on Amazon Linux 2:

  1. October 31, 2026 - deprecation. AWS may stop applying security patches and other updates, functions lose eligibility for technical support, and the Lambda console no longer lets you create or update python3.10 functions. The AWS CLI, AWS SAM and CloudFormation still work.
  2. July 29, 2027 - block function create. New python3.10 functions can no longer be created by any method.
  3. August 31, 2027 - block function update. Code and configuration updates to existing python3.10 functions are blocked. Switching the runtime to a supported version is still allowed, but from that point you can no longer switch back to python3.10.

Existing functions keep running after all three dates; AWS says deprecated runtimes can still be invoked indefinitely. They are provided as-is, though, and AWS warns that problems such as certificate expiry can eventually break them.

There is also an operating system angle. Amazon Linux 2 reached end of life on June 30, 2026, and AWS states that AL2-based runtimes, including python3.10 and python3.11, receive critical and selected important AL2 security fixes only until their own deprecation dates. The python3.12 and later runtimes run on Amazon Linux 2023.

Lambda Python runtime deprecation dates

  • python3.10 (AL2): deprecated October 31, 2026
  • python3.11 (AL2): deprecated June 30, 2027
  • python3.12 (AL2023): deprecated October 31, 2028
  • python3.13 and python3.14 (AL2023): deprecated June 30, 2029
  • python3.15 (AL2023): in public preview, with general availability targeted for November 2026; AWS says preview runtimes are not for production

How to find affected functions

AWS sends deprecation notices by email and through the Health Dashboard at least 180 days ahead, but those lists cover only $LATEST versions. For a complete picture, use the Trusted Advisor check for Lambda functions using deprecated runtimes, which also covers published versions, or query each region with the AWS CLI, as shown in the AWS guide to listing deprecated-runtime functions:

aws lambda list-functions --function-version ALL --region us-east-1 --output text --query "Functions[?Runtime=='python3.10'].FunctionArn"

Repeat the command for every region and every account. Functions packaged as container images get no deprecation notices at all, so check your Dockerfiles for public.ecr.aws/lambda/python:3.10 base images separately.

Upgrading python3.10 functions to 3.12 or 3.13

  • Rebuild dependencies. Compiled extension modules built for CPython 3.10 (cp310 wheels) generally will not load on 3.12 or 3.13. Reinstall packages for the new Python version and the target architecture (x86_64 or arm64).
  • Rebuild layers. Layers with native code need new builds, and their compatible runtimes list should include the new identifier.
  • Bundle the SDK. AWS recommends shipping your own boto3 version instead of relying on the copy included in the runtime.
  • Deploy safely. Publish a version, shift an alias, and keep the previous version available until the new runtime is proven in production.

Other clouds: Google Cloud and Azure

Google Cloud's runtime support schedule lists python310 for Cloud Run functions and 1st gen functions as deprecated from October 4, 2026, with decommission on April 4, 2027. After decommission, Google says you can no longer create or update workloads on that runtime, and existing ones may be disabled.

Azure Functions gives October 2026 as the expected end of support for Python 3.10. It also notes that Python 3.12 is the last Python version added to the Linux Consumption plan, so apps there that need 3.13 or 3.14 have to move to another plan; Microsoft points to Flex Consumption.

For related platform deadlines this month, see our Kubernetes 1.34 end-of-life guide and OpenSSL 3.4 end of life, plus ongoing coverage in Cloud and DevOps tooling.

Frequently asked questions

When is Python 3.10 end of life?

October 1, 2026, per the Python developer guide. Upstream security fixes for the 3.10 branch have stopped.

Will my python3.10 Lambda functions stop working on October 31, 2026?

No. They keep running, and you can still deploy changes through the CLI, SAM or CloudFormation until August 31, 2027. What ends on October 31, 2026 is patching, technical support and console editing.