Northern Thailand centres on Chiang Mai's old-city walls and Doi Suthep temple above, with Pai's mountain backpacker valley to the north, the Golden Triangle on the Mekong's Burmese frontier, and the elephant sanctuaries around Mae Taeng.
Cool dry season with Loi Krathong floating-lantern festival in November, Chiang Mai Flower Festival first weekend of February, and northern hill-tribe villages accessible.
Yi Peng lantern festival coincides with Loi Krathong with thousands of paper sky lanterns released over the moats and Ping River, the year's defining cultural moment.
Hot dry season with northern burning haze peaking March-April, but Songkran Thai New Year in mid-April brings the country's biggest water-fight celebrations.
Wet season with afternoon storms, Doi Inthanon's waterfalls at peak flow, and rates dropping across Chiang Mai's old-city guesthouses.