Paired air-water annual temperature patterns reveal hydrogeological controls on stream thermal regimes at watershed to continental scales

•Paired air-water annual signals are a promising tool for stream thermal regimes.•Air temperature adds critical information for water thermal regime classification.•Strong shallow to deep GW influence was indicated in small and large streams.•Local hydrogeological controls are important for stream temperature heterogeneity.•The methods described here can be efficiently applied to readily available data.