Originally Posted by
Carbonfiberboy
Not my experience. Changing weather will only change it by maybe 100'. I get very accurate repeatable readouts from my Edge 800. Very accurate meaning compared with the estimate from any mapping website. You've had a different experience?
On my edge 305, I've got three routes last week that have 1080 feet elevation gain corrected (all within a couple of feet for different days). When I look at the uncorrected, I get a variation of more than 120 feet between days and 80 feet difference gain/drop for a round trip commute (where two legs were separated by about 10 hours).
I do find that my 305 is much more accurate in altitude gain/loss than either my Forerunner 301 (with no barometer) or my smartphones. And I use Garmin Connect and find that they sometimes do an iffy job correcting the elevation. So I don't really have a great solution.