diff --git a/README.md b/README.md
index 231b168d1..897739f1b 100644
--- a/README.md
+++ b/README.md
@@ -22,21 +22,21 @@ A generic event data model for future HEP collider experiments.
 
 | | | |
 |-|-|-|
-| [EventHeader](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L148)         | [MCParticle](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L158)        | [SimTrackerHit](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L227)         |
-| [CaloHitContribution](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L261) | [SimCalorimeterHit](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L273) | [RawCalorimeterHit](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L285)     |
-| [CalorimeterHit](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L294)      | [ParticleID](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L306)        | [Cluster](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L319)               |
-| [TrackerHit](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L340)          | [TrackerHitPlane](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L357)   | [RawTimeSeries](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L378)                |
-| [Track](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L391)               | [Vertex](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L410)            | [ReconstructedParticle](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L427) |
-| [SimPrimaryIonizationCluster](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L531) | [TrackerPulse](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L549) | [RecIonizationCluster](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L562) |
-| [TimeSeries](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L573) | [RecDqdx](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L585) |                                                                                          |
+| [EventHeader](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L148)         | [MCParticle](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L160)        | [SimTrackerHit](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L229)         |
+| [CaloHitContribution](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L263) | [SimCalorimeterHit](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L275) | [RawCalorimeterHit](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L287)     |
+| [CalorimeterHit](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L296)      | [ParticleID](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L308)        | [Cluster](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L321)               |
+| [TrackerHit](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L342)          | [TrackerHitPlane](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L359)   | [RawTimeSeries](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L380)                |
+| [Track](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L393)               | [Vertex](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L412)            | [ReconstructedParticle](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L429) |
+| [SimPrimaryIonizationCluster](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L533) | [TrackerPulse](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L551) | [RecIonizationCluster](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L564) |
+| [TimeSeries](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L575) | [RecDqdx](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L587) |                                                                                          |
 
 **Associations**
 
 | | | |
 |-|-|-|
-| [MCRecoParticleAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L457)        | [MCRecoCaloAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L466)         | [MCRecoTrackerAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L475)         |
-| [MCRecoTrackerHitPlaneAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L484) | [MCRecoCaloParticleAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L493) | [MCRecoClusterParticleAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L502) |
-| [MCRecoTrackParticleAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L511)   | [RecoParticleVertexAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L520) |                                                                                                      |
+| [MCRecoParticleAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L459)        | [MCRecoCaloAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L468)         | [MCRecoTrackerAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L477)         |
+| [MCRecoTrackerHitPlaneAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L486) | [MCRecoCaloParticleAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L495) | [MCRecoClusterParticleAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L504) |
+| [MCRecoTrackParticleAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L513)   | [RecoParticleVertexAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L522) |                                                                                                      |
 
 The tests and examples in the `tests` directory show how to read, write, and use these types in your code.
 
diff --git a/edm4hep.yaml b/edm4hep.yaml
index cb930a968..44e8c0807 100644
--- a/edm4hep.yaml
+++ b/edm4hep.yaml
@@ -153,6 +153,8 @@ datatypes:
       - int32_t runNumber      //run number
       - uint64_t timeStamp     //time stamp
       - float weight       // event weight
+    VectorMembers:
+      - double weights       // event weights in case there are multiple. **NOTE that weights[0] might not be the same as weight!** Event weight names should be stored using the edm4hep::EventWeights name in the file level metadata.
 
 
   edm4hep::MCParticle:
diff --git a/include/edm4hep/Constants.h b/include/edm4hep/Constants.h
index 48b09d6dc..81dde40ea 100644
--- a/include/edm4hep/Constants.h
+++ b/include/edm4hep/Constants.h
@@ -22,6 +22,7 @@
 namespace edm4hep {
 static constexpr const char* CellIDEncoding = "CellIDEncoding";
 static constexpr const char* EventHeaderName = "EventHeader";
+static constexpr const char* EventWeights = "EventWeightNames";
 } // namespace edm4hep
 
 #endif // EDM4HEP_CONSTANTS_H