Fall in Chiang Rai really changes things up after the heavy summer rains. You’ll notice daytime temperatures drop from the mid-80s °F in September down to the low 80s °F by November, while nights cool off into the low 60s °F.
This season feels way more comfortable than the humid, rainy months before it.
Rainfall drops off fast during fall. September still brings frequent showers, but by November, it’s much drier.
Humidity falls too, so the air gets lighter as autumn rolls on. By late fall, you get clearer skies, shorter days, and a calm vibe that’s nothing like the tropical summer.
If you’re thinking of visiting, fall gives you warm days, cool evenings, and fewer rainy surprises. These weather changes affect everything, from what you pack to which activities make sense—maybe hiking in the hills, wandering through temples, or just enjoying a slower pace in the city.
Overview of Fall Weather in Chiang Rai
Chiang Rai’s fall brings cooler temps, lower humidity, and a sharp drop in rain compared to summer’s monsoon. You’ll really feel the seasonal shift as the wet season fades out and the dry season starts.
It’s honestly one of the most comfortable times to be here.
Typical Climate Patterns
During fall, daily highs gradually drop from about 87°F (31°C) in September to around 82°F (28°C) by the end of November.
Nights cool down even more, from the mid-70s°F (24°C) to the low 60s°F (16°C).
Humidity drops, too. Early fall feels muggy, but by November, the air is much drier. That makes mornings and evenings way more pleasant if you’re out and about.
Rainfall really decreases. September still brings regular showers, but by November, rain is rare. You’ll see more sunshine as the season goes on.
Key points:
- Highs: 82–87°F (28–31°C)
- Lows: 61–75°F (16–24°C)
- Humidity drops fast
- More sunny days late in the season
Transition from Wet to Dry Season
Fall is when Chiang Rai shifts from the Southwest Monsoon to the dry season. September still feels rainy, but by October, showers become less frequent. By November, it’s mostly dry.
Rainfall starts high, about 9 inches (23 cm) in early fall, but drops to under 1 inch (2 cm) by late November. That’s a big change and pretty noticeable if you’re here.
The skies clear up, too. Cloud cover drops from almost 90% in September to about 30% by November. You’ll get better mountain views and more chances to explore outdoors.
Key Weather Influences
Chiang Rai’s tropical savanna climate and its spot near the mountains shape fall weather. The retreat of the monsoon winds ends the heavy rain.
Winds shift direction as the season goes on. In September, they blow from the south, bringing moisture. By November, they come from the north, bringing cooler, drier air.
Days get shorter, too. You lose about 1.5 hours of daylight from September to November, so sunsets come earlier. It’s a gradual change, but it does affect when you’ll want to plan your outdoor time.
All these factors combine to make fall feel balanced—warm but not hot, humid at first but nicer as the weeks pass, and a lot less rainy than summer.
Temperature Trends During Fall
Fall in Chiang Rai means steady cooling from September to November. Highs ease down, nights get much cooler, and the gap between warm days and cool nights grows.
Average Highs and Lows
You’ll see high temperatures drop from around 87°F (31°C) in mid-September to about 82°F (28°C) by late November. Highs rarely dip below 75°F (24°C), so afternoons stay comfortable for being outside.
The average lows drop more noticeably. Early fall nights average near 75°F (24°C), but by late November, they’re down to about 61°F (16°C). Sometimes, it can get as cool as 54°F (12°C).
You’ll definitely feel the difference in mornings and evenings as fall moves along. Bringing a light jacket or sweater is smart if you’re out after sunset.
Monthly Temperature Changes
The temperature drop happens gradually but steadily over fall.
- September: Warmest, with highs near 87°F (31°C) and lows around 75°F (24°C).
- October: Transition month, highs about 85°F (29°C), lows around 68°F (20°C).
- November: Coolest, highs near 82°F (28°C), lows averaging 61°F (16°C).
This breakdown shows how Chiang Rai shifts from late-summer humidity to cooler, drier weather. By November, days are mild and nights are crisp—a great time to explore northern Thailand.
Nighttime Versus Daytime Temperatures
The gap between day and night temps gets bigger as fall goes on. In September, the difference is usually 10–12°F (5–6°C). By November, it’s almost 20°F (11°C).
Days stay warm, but after sunset, things cool quickly. Evenings are pleasant, but you might want warmer clothes if you’re out late or in the countryside.
These bigger swings between day and night really show the shift from rainy to dry season, and they matter for both comfort and planning your trip.
Rainfall and Humidity in Autumn Months
Autumn in Chiang Rai means a steady move from peak rainy season to drier, clearer weather. Rainfall, wet days, and humidity all change a lot between September and November.
Average Rainfall by Month
September still brings heavy rainfall, with 300–350 mm for the month. It’s one of the wettest times of the year, and downpours can last for hours.
By October, rainfall drops to about 120–150 mm. Showers get shorter and less intense, and you’ll see more sun between storms.
November marks a clear shift to the dry season. Rainfall drops to around 30–50 mm, and many days stay dry. This month usually brings some of the best weather for being outdoors.
| Month | Average Rainfall (mm) |
|---|---|
| September | 300–350 |
| October | 120–150 |
| November | 30–50 |
Rainy Days Frequency
Rainy days drop off as fall goes on. In September, expect 18–22 days with measurable rain. Most storms hit in the afternoon or evening, but some days stay overcast.
October usually has 8–12 rainy days, so you get more dry mornings and clearer skies. Rain is still possible, but it doesn’t rule your plans.
By November, rain falls on just 1–3 days most years, and showers are quick. November is one of the most reliable months for outdoor plans.
Relative Humidity Patterns
Humidity stays high in September, averaging 80–84%. The mix of rain and clouds keeps the air heavy, which can feel a bit much during hot afternoons.
In October, humidity drops to about 70–75%. That, plus cooler evenings, makes things feel a lot more comfortable.
By November, humidity falls further to around 65–70%. The drier air and lower rainfall make it nicer for walking, sightseeing, and being outside. This steady drop in humidity really signals the arrival of the dry season.
Wind and Sunshine Patterns
Fall in Chiang Rai brings light, steady winds and shorter days. You’ll notice calm breezes and less sunshine as the season moves along, which changes how comfy it feels and when you’ll want to be outdoors.
Typical Wind Speed in Fall
Wind speeds don’t change much in fall. They average around 3.1 miles per hour, which is light and not really noticeable.
Wind direction does shift, though. From early September to mid-October, winds mainly blow from the south. By late October, they come from the east, and in November, from the north.
Since winds stay gentle, you won’t get strong gusts or sudden changes. Outdoor conditions stay pretty predictable for walking, biking, or hitting up markets.
Even light winds help bring down humidity, especially as rain drops off. That’s part of why late November feels so much better than the soggy months before.
Average Daily Sunshine Hours
Sunlight decreases during fall. In early September, you get about 12 hours and 30 minutes of daylight. By late November, it’s just over 11 hours.
Cloudy days drop, too. At first, skies are mostly overcast, but by November, most days are clear or partly sunny. That means more reliable sunshine for sightseeing.
Daily sunshine averages 7–9 hours, depending on clouds and rain. The clearest days come at the end of November, with skies clear about two-thirds of the time.
This matters if you’re planning trips to temples, mountain viewpoints, or festivals. Shorter days mean earlier sunsets, so you’ll want to plan your activities accordingly.
Best Time for Travel in the Fall
Fall in Chiang Rai means a switch from rainy to cooler, drier weather. You get better days for sightseeing, with less humidity and fewer rainy afternoons compared to summer.
Comfort Levels for Outdoor Activities
From September to November, daytime temps drop from around 30°C to about 28°C. Nights can get down to 16°C, which might feel chillier than you’d expect in Thailand.
Rain falls off fast. Early September still has heavy showers, but by late November, average monthly rain can dip below 20 mm. That makes outdoor plans much more dependable.
Clouds clear, too. Skies go from mostly overcast in September to partly sunny by November.
Humidity drops as fall goes on. Early fall can feel muggy, but by late November, the air is much drier—perfect for walking tours, temple visits, or hiking. Even as days get a bit shorter, you’ll still have 11–12 hours of usable light.
These conditions make mid to late fall a great time to explore the Golden Triangle, visit mountain villages, or cycle through the countryside.
Travel Tips for Autumn Visits
Pack for warm days and cool nights. Lightweight shirts and shorts are fine for daytime, but bring a light jacket or sweater for evenings, especially if you’re heading into the hills.
If you come in early fall, bring an umbrella or rain jacket—September can still be wet. By November, you probably won’t need rain gear, but comfy walking shoes are always a good idea.
Plan your schedule with the weather in mind. Early mornings and late afternoons are usually the nicest for sightseeing, while midday can still feel warm.
If you’re into local culture, fall is festival season. Loy Krathong usually happens in November, and joining in gives you a chance to see Chiang Rai’s traditions while enjoying the milder weather.
What to Expect: Practical Tips for Visitors
When you visit Chiang Rai in the fall, mornings feel pretty cool, afternoons warm up nicely, and you might get caught in a rain shower or two. If you plan ahead with the right clothes and basic health stuff, you’ll probably avoid most of the usual travel headaches in northern Thailand.
Packing Recommendations
During fall, temperatures usually sit somewhere between 18°C and 28°C (64°F to 82°F). You’ll notice that mornings and evenings can get a bit chilly, but midday is still warm enough for short sleeves. I’d pack lightweight clothing for the daytime, but don’t forget a light jacket or sweater for when it cools down.
Since rain showers can pop up, especially in September and October, you’ll want a small umbrella or a rain jacket. If you’re planning to wander through temples or markets, wear shoes that dry quickly or just go with comfortable walking sandals.
Planning to hike? Bring breathable fabrics and make sure you have sturdy shoes with some grip. Trails get slippery after it rains, trust me.
Don’t skip a hat, sunglasses, and sunscreen—the sun might not feel as harsh, but it’s still strong even in cooler weather.
If you’re heading to religious sites, pack modest clothing that covers your shoulders and knees. Toss a scarf or shawl in your bag for quick cover-ups when you want to pop into a temple.
Health and Safety Considerations
You’ll probably notice the air feels fresher in fall compared to the dry season, but mosquitoes still show up—especially after it rains. I’d pack some insect repellent, and honestly, long sleeves and pants in the evenings can save you a lot of itching.
Don’t forget to stay hydrated. Those warm afternoons sneak up on you, and a little outdoor exploring can leave you drained fast. Bring a refillable water bottle, and stick to safe drinking water if you can.
If you deal with allergies, the humidity and all that new plant growth in fall might set you off a bit. Keep your meds on hand. Sure, pharmacies in Chiang Rai aren’t hard to find, but it’s just easier to have your own stash.
City traffic isn’t too bad, but rural roads get pretty narrow and slick when it’s wet. If you’re thinking about renting a motorbike or bicycle, just take it easy. Definitely wear a helmet, and I wouldn’t recommend riding after dark in quiet areas.