Proposed Release Schedule for SciPy 1.18.0

Announcements
1

Hi all,

I’m proposing the release schedule for SciPy 1.18.0 below and I’m happy to hear feedback/requests for adjustments if needed.

  • 2026-05-17T06:00:00Z branch maintenance/1.18.x
  • 2026-05-21T06:00:00Z SciPy 1.18.0rc1 release
  • 2026-06-04T06:00:00Z SciPy 1.18.0rc2 release (if needed)
  • 2026-06-18T06:00:00Z SciPy 1.18.0 “final” release

Current tallies for 1.18.0 milestone:

Major thrusts I’m aware of (let me know of any specific blockers for branching):

  • ILP64 linalg support
  • array API support
  • batching support
  • narrowing of supported linalg dtypes/deprecations related to that?
  • optional capability of building in absence of Fortran compiler

If we end up ahead of the NumPy schedule for whatever reason, we may delay slightly just to make sure everything is “ok” with their latest stable release first, but usually Chuck gets the stable release out faster than I each cycle as intended.

1 Like
2

Thanks Tyler!
The schedule looks good to me, and the list of major items looks good too.
One potentially high-profile item is AVX addition of ENH:linalg.bandwidth: Implement AVX2 SIMD enabled branches for GCC/Clang + X86_64 by ilayn · Pull Request #24994 · scipy/scipy · GitHub : not a release blocker of course, and a TBD, but if it lands in 1.18, it looks like a highlight to me.

Cheers,

Evgeni

3

Thanks Tyler! the schedule LGTM too.

One thing I have in mind as something that needs resolving before rc1 is the Cython ABI issue in BUG: ABI-breaking changes for `cython_special.bdtrik` & co in `main` · Issue #24937 · scipy/scipy · GitHub. Related: for whoever uses any Cython APIs (cython_blas, cython_lapack, cython_special, cython_optimize), it’d be great to test that everything looks fine - we’ve been testing with scikit-learn and statsmodels for linalg, but not with anything else. It seems like we’ve been breaking the ABI in minor ways with every release (Cython makes that very easy to do).