A system for improving vehicle efficiency in terms of fuel saving and/or time accuracy through onboard weather update, the system comprising: a processor; and a non-transitory processor readable medium including instructions, executable by the processor, to perform a method comprising: receiving weather data related to a vehicle traveling from an origin location to a destination location from an onboard vehicle data source; receiving real-time weather data from one or more weather data sources; detecting when onboard forecast weather data is different than the real-time weather data based on the weather data related to the vehicle for at least one segment of a plurality of segments of a vehicle travel path, wherein a segment comprises a climb, cruise, or descent segment; determining, based on the real-time weather data and the weather data related to the vehicle, a weather error for each of the at least one segment of a plurality of segments of the vehicle travel path; determining an error threshold for each of the at least one segment of a plurality of segments of the vehicle travel path, wherein if the weather error for a given flight segment of the at least one segment of a plurality of segments of the vehicle travel path is greater than a corresponding error threshold for the given flight segment, then: estimating based on the real-time weather data and the weather data related to the vehicle, one or more potential benefits in terms of fuel saving and/or time accuracy from an update of the onboard forecast weather data to the given flight segment; and updating when the one or more potential benefits is above a predefined threshold, the onboard forecast weather data to the real-time weather data for the at least one segment of a plurality of segments of the vehicle travel path a processor; and a non-transitory processor readable medium including instructions, executable by the processor, to perform a method comprising: receiving weather data related to a vehicle traveling from an origin location to a destination location from an onboard vehicle data source; receiving real-time weather data from one or more weather data sources; detecting when onboard forecast weather data is different than the real-time weather data based on the weather data related to the vehicle for at least one segment of a plurality of segments of a vehicle travel path, wherein a segment comprises a climb, cruise, or descent segment; determining, based on the real-time weather data and the weather data related to the vehicle, a weather error for each of the at least one segment of a plurality of segments of the vehicle travel path; determining an error threshold for each of the at least one segment of a plurality of segments of the vehicle travel path, wherein if the weather error for a given flight segment of the at least one segment of a plurality of segments of the vehicle travel path is greater than a corresponding error threshold for the given flight segment, then: estimating based on the real-time weather data and the weather data related to the vehicle, one or more potential benefits in terms of fuel saving and/or time accuracy from an update of the onboard forecast weather data to the given flight segment; and updating when the one or more potential benefits is above a predefined threshold, the onboard forecast weather data to the real-time weather data for the at least one segment of a plurality of segments of the vehicle travel path receiving weather data related to a vehicle traveling from an origin location to a destination location from an onboard vehicle data source; receiving real-time weather data from one or more weather data sources; detecting when onboard forecast weather data is different than the real-time weather data based on the weather data related to the vehicle for at least one segment of a plurality of segments of a vehicle travel path, wherein a segment comprises a climb, cruise, or descent segment; determining, based on the real-time weather data and the weather data related to the vehicle, a weather error for each of the at least one segment of a plurality of segments of the vehicle travel path; determining an error threshold for each of the at least one segment of a plurality of segments of the vehicle travel path, wherein if the weather error for a given flight segment of the at least one segment of a plurality of segments of the vehicle travel path is greater than a corresponding error threshold for the given flight segment, then: estimating based on the real-time weather data and the weather data related to the vehicle, one or more potential benefits in terms of fuel saving and/or time accuracy from an update of the onboard forecast weather data to the given flight segment; and updating when the one or more potential benefits is above a predefined threshold, the onboard forecast weather data to the real-time weather data for the at least one segment of a plurality of segments of the vehicle travel path estimating based on the real-time weather data and the weather data related to the vehicle, one or more potential benefits in terms of fuel saving and/or time accuracy from an update of the onboard forecast weather data to the given flight segment; and updating when the one or more potential benefits is above a predefined threshold, the onboard forecast weather data to the real-time weather data for the at least one segment of a plurality of segments of the vehicle travel path