Personally I find such talk strange, since here in Oregon it's been cold and rainy (and even snowed last night), but that's another matter.
But weirdest weather ever? Weirder than the Dust Bowl years? Than any of various "storms of the century," or 1972's Hurricane Agnes, a June hurricane that swept away all our lawn furniture and precipitated a 20-year feud between my grandmother and my great uncle-in-law when she suggested, as we were standing around watching the water come up, that he'd better get his Volkswagen Bug out of our driveway before it floated away. (I suspect there must have been bad feelings between them already, and this was just the last straw.) Me, I believe the absolutely weirdest weather in the U.S. occurred on August 25, 1814, when, just as the British were setting fire to Washington D.C. -- the Americans having all fled the day before, including Dolley Madison with some valuable paintings -- a hurricane appeared out of the blue and put out the fires, saving the city and, quite possibly, the nation.
Anyway it's certainly been a warm March in the U.S., but conveniently McKibben doesn't mention that the rest of the globe has had a fairly cold winter (Dec-Feb). Globally, UAH measured the lower troposphere to rank 19th out of 34 years; the USA48 ranking was 4th (last year it was 26th).
UAH's trend for USA48 over their 34-year record is 0.21 ± 0.04 C/decade. That's worrisome enough, and it what really he ought to cite, but I guess it's not scary enough and he needs to take advantage of a heat wave while its here.
McKibben does this a lot, like with last year's Hurricane Irene, which he attributed to warm water off the east coast. Yet the 2011 Atlantic hurricane season had a near normal number of major hurricanes, with an above average number of tropical storms with a near normal number of major hurricanes. Back then KcKibben picked off all the global hot spots:
"Last year was the warmest ever recorded on planet Earth. Arctic sea ice is near all-time record lows. Record floods from Pakistan to Queensland to the Mississippi basin; record drought from the steppes of Russia to the plains of Texas. Just about the only trauma we haven’t had are hurricanes plowing into the U.S., but that’s just luck—last year was a big storm year, but they all veered out to sea. This year we’re already on letter I—which in a normal year we don’t get to until well into October."Now he sticks to the US heat wave, with no mention of the recent deep freeze in eastern Europe. And if you want to cherry pick, Arctic sea ice is currently at it highest extent in several years.