September definitely still sees its share of rain. It's monsoon season on the coast and places like Ngapali and other beaches on the Bay of Bengal are closed dues to washed-out roads. Yangon remains rainy, although it's mostly confined to the afternoons. The mornings can be dry (but humid) with temperatures around 90 degrees Fahrenheit.
In the north part of the central plains around Bagan and Mandalay, temperatures hover in the mid-80s and the weather is slightly drier (although these cities still see rainfall of 5 to 6 inches in September). The mountains around Inle Lake are cooler, averaging around 77 degrees.
Crowds and Costs
During this time of year, the crowds are minimal. You'll see people starting to arrive (there are definitely more visitors than in July or August) but it's nothing like the crowds that start in October and November when high season gets underway. The temples in Bagan, Mandalay, and Yangon will have tourists milling about but there aren't rows of tour buses lined up outside. Inle Lake will also have visitors starting to fill up the hotels and lodges, but you'll still be able to cruise around the water or check out the markets without fighting for room.
Where to Go
September is an excellent month to visit Mandalay, Bagan, or both (they're only about 30 minutes apart by plane)—as long as you can handle a little bit of rain. The temperature in these cities is about 84 to 86 degrees which is warm but not unbearably so, and the mornings are often dry. It's muggy this time of year so be prepared for that but overall the weather is decent. You'll likely experience rainstorms in the afternoons with intermittent breaks for sunshine.
If you have a good raincoat, the northern towns outside Mandalay can be beautiful this time of year, too. In places like Pyin Oo Lwin or Hsipaw, the hills are green and lush and, though it's still quite wet (you'll most likely get rained on of you go trekking), the landscape offers views you can't find during the high season. It's a wonderful time to bundle up and take a hike into the dewy, rainy forests to check out all of their splendor.
This is also a great time for visiting Kalaw and Inle Lake. Similarly to Mandalay and Bagan, these areas experience a combination of rainy and sunny conditions in September. The mornings tend to be misty and beautiful, and even the thunderstorms have a mystical quality over the water. The temperatures are generally in the high 70s.
Yangon will be the rainiest of Myanmar's "Big Four" destinations in September. It will also be the hottest at around 90 degrees Fahrenheit. However, it's much drier than July and August with plenty of breaks in the rain. Additionally, Yangon offers lots of indoor tourist attractions such as temples and museums, so even if it's rainy you'll have plenty to do.
The beaches of Ngapali, Ngwe Saung, and other parts of the coast will still be contending with monsoons in September so stay away from these areas.
What to Do
In Bagan, check out the temples and archaeological ruins, all of which are chock-full of ancient Burmese history. Just make sure to plan your tours in the morning so that if the rains roll in, you'll be done by then and can hunker down in one of the restaurants or hotel bars. If it's a clear morning, check out sunrise at the Shwezigon Temple or jump on a Grasshopper Adventures cycling tour to see a handful of ruins by bike.
Just 180 miles from Bagan is Mandalay, a charming Burmese city with a wide variety of tourist attractions. Check out the striking Hsinbyume Pagoda, a white-colored shrine in the Mingun area that's surrounded by rolling green hills. Just keep in mind that this is an outdoor temple so if the weather is wet, it may be best to save it for another day.
Hiking Mandalay Hill is a good rainy day option because you reach it via a Buddhist shrine. The shrine has 1,729 steps leading up to the lookout, most of which are outdoors but covered. North of Mandalay in Pyin Oo Lwin, the town's botanical garden will be in bloom in September, offering a rich array of plants and flowers. Around Hsipaw, also nearby, there are beautiful hiking trails.
As you move farther south and into the mountains of Inle Lake, take a long-boat ride through the markets and see the houses on stilts. You'll have the opportunity to visit the famous cigar ladies who can show you how they roll tobacco, or pop by the Nga Phe Kyaung Monastery where the cats roam freely with the monks. It's also a great time to visit the Red Mountain Estate Vineyards where you can sip Merlot at sunset with rolling hills in the background. In Yangon, drop by the Sule Pagoda where the monks will let you pour water over your birthday Buddha.
Events in September
Bo Bo Gyi Nat Festival: On the banks of Taungthaman Lake near the famous U Bein Bridge, the people of Amarapura hold a 10-day festival in late September (or sometimes early October) to honor the pagoda there. Participants toss tea leaves at each other and if you get hit, it's a tradition that you must return the following year. During the event, there is a large procession barge that travels from Taungthaman Village to Kun Taung Lake with villagers following in sampan boats.
Manuha Pagoda Festival: This three-day festival in Myanmar takes place in Bagan on the full month of Tawthalin (the sixth month of the Burmese calendar). This typically falls in late September or early October and involves a big papier-mache parade through the streets with music and festivities.
Phaung Daw Oo Pagoda Festival: Another event that occurs in late September or early October, this Inle Lake-based celebration honors the Phaung Daw Oo Pagoda. Celebrants partake in a procession of leg-rowed boats (the type that all of the fishermen row in the iconic Inle Lake postcards) while tugging giant Buddha statues across the lake. It's a memorable sight that draws thousands of spectators to the popular festival.
Traveling to Myanmar in September? Check out this great itinerary
Magnificent Myanmar – 8 Days: This eight-day itinerary, which includes visits to Yangon, Bagan, Mandalay, and Inle Lake, is an excellent choice for September travelers.