In the rainy season, mornings are the base of a Bangkok plan. The Damnoen Saduak half day leaves Siam MBK at 07:50 and is back in the early afternoon, and the 09:00 slot of the Grand Palace and Wat Pho tour clears the rest of the day. Showers often gather in the afternoon, so fix the morning first and fit the rest around it.
If you want a plan that looks the same in any weather, add a cooking class. Blue Elephant has a market visit in the morning session and none in the afternoon, and Siamese Cookery House has an 18:00 evening session you can switch to if the day is wet. Mango Cooking School says its market stage can be cancelled in rain.
For parents and children, choose by the amount of walking and by age rules. The Grand Palace and Wat Pho point tour includes a tuk-tuk transfer and ends in three and a half hours, while the lion park has no fixed route so you can set the pace. At Blue Elephant children aged 6 to 12 join with a parent and those aged 5 and under cannot.
Most outdoor tours share one rain rule. The Damnoen Saduak, Grand Palace and Muang Boran listings all say they run in the rain and give no refund if rain interrupts them. Pack raincoats, an umbrella and spare shoes, and carry baht for the products that charge entrance in cash.
If you can give up a whole day, the private Ayutthaya taxi is the flexible choice. Temple admissions and a longtail boat are included and it starts at your hotel, but no guide is provided. At 11 hours it suits one day of a four-day trip, with morning half days or classes on the others.