# TrendBaseline A type encapsulating everything there is to know about what a trend baseline is. ``` struct TrendBaseline where Dimension : Dimension ``` ## Topics ### Instance Properties [`let kind: TrendBaseline.Kind`](/documentation/WeatherKit/TrendBaseline/kind-swift.property) The manner in which the comparison between the baseline and current values are compared. [`let startDate: Date`](/documentation/WeatherKit/TrendBaseline/startDate) The year the statistics collection began. [`let value: Measurement`](/documentation/WeatherKit/TrendBaseline/value) The recorded baseline value for the condition in which the trend is comparing to. ### Enumerations [`enum Kind`](/documentation/WeatherKit/TrendBaseline/Kind-swift.enum) An enum describing what value is being compared between historical and current readings. ## Relationships ### Conforms To [`Equatable`](/documentation/Swift/Equatable) [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`Encodable`](/documentation/Swift/Encodable) [`Decodable`](/documentation/Swift/Decodable) [`Sendable`](/documentation/Swift/Sendable) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)