Answer
As you transition from the hot season, which peaks around April, into the rainy season by June, you can expect a shift in temperatures and humidity. Days will still be quite warm, often reaching around 32°C (90°F), but the evenings may start to feel a bit cooler as rain becomes more frequent.
• With the onset of the rainy season, expect afternoon showers to become common, usually short but quite intense. This means it's wise to carry an umbrella or raincoat, especially if you plan on outdoor activities.
• The humidity will rise, making it feel stickier than before, so light, breathable clothing is a must. However, the rain will also bring a refreshing change to the air and make the landscape incredibly lush and vibrant.
Practical Chiang Mai planning note: For weather and air quality, check a current forecast and a live air-quality source shortly before the activity. Northern Thailand can experience strong seasonal variation, and conditions differ between the city, foothills and higher mountains.