On its website, NOAA has a wide selection of proxy studies, accompanied by the data on which they are based. Specifically, they have this to say on the MWP:
The idea of a global or hemispheric “Medieval Warm Period” that was warmer than today, however, has turned out to be incorrect.The linked NOAA page doesn't contain that statement, not even the word incorrect. What it does say, however is this
Medieval Warm Period - 9th to 13th Centuries
Norse seafaring and colonization around the North Atlantic at the end of the 9th century indicated that regional North Atlantic climate was warmer during medieval times than during the cooler "Little Ice Age" of the 15th - 19th centuries. As paleoclimatic records have become more numerous, it has become apparent that "Medieval Warm Period" or "Medieval Optimum" temperatures were warmer over the Northern Hemisphere than during the subsequent "Little Ice Age", and also comparable to temperatures during the early 20th century. The regional patterns and the magnitude of this warmth remain an area of active research because the data become sparse going back in time prior to the last four centuries.A paragraph which says the exact opposite to what Grist's Coby Beck says it does. A neat and total rebuttal of the lie, for that is what it is. I think the phrase "warmer over the Northern Hemisphere" is the clincher. The post is just a vehicle to direct readers to a realclimate "rebuttal" IMHO. Beck clearly thinks his readers just won't bother or are too dumb or trusting to check the source, but I'm the guy who wrote "The truth may be only a click away", and so it was.