In other respects, too, Sydney's climate varies significantly from that of other areas with humid continental climates. The most significant variations are that Sydney experiences unusually cool summers, and relatively windy, wet and stormy winters, relative to other humid-continental areas such as in the interior of North America. Annual temperatures are instead rather similar to areas around the Baltic Sea in north-eastern Europe at much higher latitudes, although Sydney's seasonal lag is stronger. Although Sydney has some maritime influence, similar latitudes on the other side of the Atlantic have significantly milder climates in all seasons except summer. Sydney is in the direct path of fall and winter storms (in the U.S., called nor'easters) migrating from the U.S. Northeastern and New England states; these storms can attain tremendous intensity by the time they approach Sydney, with high winds, heavy snow, ice and/or rain events common, primarily from October to March. Summer thunderstorms are rare in Sydney, because nearby bodies of cool water sharply inhibit the combination of heat and humidity that fuels summer-season thunderstorms elsewhere (for example, the United States' central and southeastern states, and east-central and northern China). In recent years, possibly due to a warming climate, this has changed. In 2013 and 2016 Sydney was under a tornado watch as a result of unusually powerful thunderstorms. On 8 August 2014, a funnel cloud appeared near the Sydney Airport although no tornado warning or tornado watch was issued and the funnel did not actually touch down.