★ January30° · ☂ 1 February 33° · ☂ 1 March 35° · ☂ 2 April 37° · ☂ 5 May 35° · ☂ 12 June 33° · ☂ 11 July 32° · ☂ 15 August 32° · ☂ 17 September 32° · ☂ 14 October 32° · ☂ 10 November 31° · ☂ 4 ★ December29° · ☂ 1 Chiang Mai in September:seriously hot, rain on every second day Chiang Mai, Thailand · Records from 2006 to 2025. Not a forecast.
Mean high 32° Hottest day 36.4° (2009)
Mean low 24° Coldest night 21.1° (2007)
Rain days 14 days 9-23 by year
Rainfall 198mm Daylight 12.5 → 12.0 h
Chiang Mai's 12 months i Best: December and January
1 2 3 4 5 6 7 8 9 10 11 12
Trip types Sightseeing on foot Poorhot, frequent rain and muggy
Humidity 83% 30 muggy days
Clear days 0 days 22 overcast days
Mean wind 4 km/h Rarely windy
Sunrise / sunset (15th) 06:11 / 18:27 Daylight 12.5 → 12.0 h
Chiang Mai in September The rains continue and wet days are still common. Carry an umbrella through the day. The month moves closer to the dry season as it goes on, so watch whether wet days thin out later in the month.
September brought serious heat to Chiang Mai, 32°C on a typical afternoon and 24°C overnight. Early mornings were the best time to be outside. About 14 days a month saw rain, enough that a wet-weather plan was worth having. The average is 14, but individual years ran from 9 (2008) to 23 (2011).
Highs topped 30°C on 26 days of the month on average. Mixing in indoor stops at midday made sense.
Typhoons i Typhoons: May
Date by date i Sun
Mon
Tue
Wed
Thu
Fri
Sat
Week
September 1 Wednesday 1 rain in 11 of 20 yrs 11/20 31° 24° September 2 Thursday 2 rain in 9 of 20 yrs 9/20 32° 24° September 3 Friday 3 rain in 10 of 20 yrs 10/20 32° 24° September 4 Saturday 4 rain in 3 of 20 yrs 3/20 33° 24° 1-4 rain on 41% of days 32° 24°
September 5 Sunday 5 rain in 10 of 20 yrs 10/20 32° 24° September 6 Monday 6 rain in 12 of 20 yrs 12/20 32° 24° September 7 Tuesday 7 rain in 10 of 20 yrs 10/20 32° 24° September 8 Wednesday 8 rain in 10 of 20 yrs 10/20 32° 24° September 9 Thursday 9 rain in 12 of 20 yrs 12/20 32° 24° September 10 Friday 10 rain in 9 of 20 yrs 9/20 31° 24° September 11 Saturday 11 rain in 9 of 20 yrs 9/20 31° 24° 5-11 rain on 51% of days 32° 24°
September 12 Sunday 12 rain in 11 of 20 yrs 11/20 31° 24° September 13 Monday 13 rain in 8 of 20 yrs 8/20 32° 24° September 14 Tuesday 14 rain in 13 of 20 yrs 13/20 31° 24° September 15 Wednesday 15 rain in 11 of 20 yrs 11/20 32° 23° September 16 Thursday 16 rain in 7 of 20 yrs 7/20 32° 24° September 17 Friday 17 rain in 9 of 20 yrs 9/20 32° 24° September 18 Saturday 18 rain in 13 of 20 yrs 13/20 31° 24° 12-18 rain on 51% of days 32° 24°
September 19 Sunday 19 rain in 6 of 20 yrs 6/20 32° 24° September 20 Monday 20 rain in 9 of 20 yrs 9/20 32° 24° September 21 Tuesday 21 rain in 8 of 20 yrs 8/20 32° 24° September 22 Wednesday 22 rain in 9 of 20 yrs 9/20 32° 23° September 23 Thursday 23 rain in 7 of 20 yrs 7/20 32° 23° September 24 Friday 24 rain in 10 of 20 yrs 10/20 32° 24° September 25 Saturday 25 rain in 9 of 20 yrs 9/20 32° 23° 19-25 rain on 41% of days 32° 24°
September 26 Sunday 26 rain in 13 of 20 yrs 13/20 32° 24° September 27 Monday 27 rain in 9 of 20 yrs 9/20 31° 23° September 28 Tuesday 28 rain in 11 of 20 yrs 11/20 32° 23° September 29 Wednesday 29 rain in 10 of 20 yrs 10/20 32° 23° September 30 Thursday 30 rain in 7 of 20 yrs 7/20 32° 23°
26-30 rain on 50% of days 32° 23°
1-4 rain on 41% of days 32° 24° 5-11 rain on 51% of days 32° 24° 12-18 rain on 51% of days 32° 24° 19-25 rain on 41% of days 32° 24° 26-30 rain on 50% of days 32° 23°
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Week
September 1 Friday 1 rain in 11 of 20 yrs 11/20 31° 24° September 2 Saturday 2 rain in 9 of 20 yrs 9/20 32° 24° 1-2 rain on 50% of days 32° 24°
September 3 Sunday 3 rain in 10 of 20 yrs 10/20 32° 24° September 4 Monday 4 rain in 3 of 20 yrs 3/20 33° 24° September 5 Tuesday 5 rain in 10 of 20 yrs 10/20 32° 24° September 6 Wednesday 6 rain in 12 of 20 yrs 12/20 32° 24° September 7 Thursday 7 rain in 10 of 20 yrs 10/20 32° 24° September 8 Friday 8 rain in 10 of 20 yrs 10/20 32° 24° September 9 Saturday 9 rain in 12 of 20 yrs 12/20 32° 24° 3-9 rain on 48% of days 32° 24°
September 10 Sunday 10 rain in 9 of 20 yrs 9/20 31° 24° September 11 Monday 11 rain in 9 of 20 yrs 9/20 31° 24° September 12 Tuesday 12 rain in 11 of 20 yrs 11/20 31° 24° September 13 Wednesday 13 rain in 8 of 20 yrs 8/20 32° 24° September 14 Thursday 14 rain in 13 of 20 yrs 13/20 31° 24° September 15 Friday 15 rain in 11 of 20 yrs 11/20 32° 23° September 16 Saturday 16 rain in 7 of 20 yrs 7/20 32° 24° 10-16 rain on 49% of days 32° 24°
September 17 Sunday 17 rain in 9 of 20 yrs 9/20 32° 24° September 18 Monday 18 rain in 13 of 20 yrs 13/20 31° 24° September 19 Tuesday 19 rain in 6 of 20 yrs 6/20 32° 24° September 20 Wednesday 20 rain in 9 of 20 yrs 9/20 32° 24° September 21 Thursday 21 rain in 8 of 20 yrs 8/20 32° 24° September 22 Friday 22 rain in 9 of 20 yrs 9/20 32° 23° September 23 Saturday 23 rain in 7 of 20 yrs 7/20 32° 23° 17-23 rain on 44% of days 32° 24°
September 24 Sunday 24 rain in 10 of 20 yrs 10/20 32° 24° September 25 Monday 25 rain in 9 of 20 yrs 9/20 32° 23° September 26 Tuesday 26 rain in 13 of 20 yrs 13/20 32° 24° September 27 Wednesday 27 rain in 9 of 20 yrs 9/20 31° 23° September 28 Thursday 28 rain in 11 of 20 yrs 11/20 32° 23° September 29 Friday 29 rain in 10 of 20 yrs 10/20 32° 23° September 30 Saturday 30 rain in 7 of 20 yrs 7/20 32° 23° 24-30 rain on 49% of days 32° 23°
1-2 rain on 50% of days 32° 24° 3-9 rain on 48% of days 32° 24° 10-16 rain on 49% of days 32° 24° 17-23 rain on 44% of days 32° 24° 24-30 rain on 49% of days 32° 23°
Tap another date to change
2006 none
2007 3mm
2008 none
2009 9mm
2010 1mm
2011 7mm
2012 1mm
2013 4mm
2014 none
2015 5mm
2016 36mm
2017 none
2018 13mm
2019 5mm
2020 none
2021 20mm
2022 8mm
2023 12mm
2024 none
2025 none
Holidays in September (2027) 1 US holidays (flights fill up)
Holidays in September (2028)
Your trip dates, the past 20 years Trip dates September 1 (Wed) 2 (Thu) 3 (Fri) 4 (Sat) 5 (Sun) 6 (Mon) 7 (Tue) 8 (Wed) 9 (Thu) 10 (Fri) 11 (Sat) 12 (Sun) 13 (Mon) 14 (Tue) 15 (Wed) 16 (Thu) 17 (Fri) 18 (Sat) 19 (Sun) 20 (Mon) 21 (Tue) 22 (Wed) 23 (Thu) 24 (Fri) 25 (Sat) 26 (Sun) 27 (Mon) 28 (Tue) 29 (Wed) 30 (Thu) ~ September 1 (Wed) 2 (Thu) 3 (Fri) 4 (Sat) 5 (Sun) 6 (Mon) 7 (Tue) 8 (Wed) 9 (Thu) 10 (Fri) 11 (Sat) 12 (Sun) 13 (Mon) 14 (Tue) 15 (Wed) 16 (Thu) 17 (Fri) 18 (Sat) 19 (Sun) 20 (Mon) 21 (Tue) 22 (Wed) 23 (Thu) 24 (Fri) 25 (Sat) 26 (Sun) 27 (Mon) 28 (Tue) 29 (Wed) 30 (Thu) 1-7 8-14 15-21 22-end Whole month
You can also click two dates on the axis. Hover a cell to see that day's rain. By year Driest trips first
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Trip rain days Month rain days Tap a date to start, tap another to end. Each cell is that date in one year. '06 '07 '08 '09 '10 '11 '12 '13 '14 '15 '16 '17 '18 '19 '20 '21 '22 '23 '24 '25
of 20 1 Wed Pick September 1
11 3 Fri Pick September 3
10 5 Sun Pick September 5
10 6 Mon Pick September 6
12 7 Tue Pick September 7
10 8 Wed Pick September 8
10 9 Thu Pick September 9
12 10 Fri Pick September 10
9 11 Sat Pick September 11
9 12 Sun Pick September 12
11 13 Mon Pick September 13
8 14 Tue Pick September 14
13 15 Wed Pick September 15
11 16 Thu Pick September 16
7 17 Fri Pick September 17
9 18 Sat Pick September 18
13 19 Sun Pick September 19
6 20 Mon Pick September 20
9 21 Tue Pick September 21
8 22 Wed Pick September 22
9 23 Thu Pick September 23
7 24 Fri Pick September 24
10 25 Sat Pick September 25
9 26 Sun Pick September 26
13 27 Mon Pick September 27
9 28 Tue Pick September 28
11 29 Wed Pick September 29
10 30 Thu Pick September 30
7 Dates outside your trip are dimmed.
One row per year, one cell per day. 2008 had 9 rain days, 2011 had 23.
Chiang Mai through the year What to pack Loose linen or quick-dry cotton, a wide-brimmed hat and sunscreen were the basics. A water bottle stayed in the bag, and midday plans moved indoors.
Averaging 14 rain days, keep a light waterproof or a compact umbrella in the bag. In windy spots umbrellas flip easily.
Common questions Does it rain a lot in Chiang Mai in September? Over the past 20 years September averaged 14 rain days (1 mm or more) out of 30. Individual years ran from 9 in the driest to 23 in the wettest.
What should I wear in Chiang Mai in September? Days averaged 32°C and nights 24°C. Pack an umbrella, sandals that can get wet, T-shirts, sunscreen plus a hat, and insect repellent.
Is September a good time to visit Chiang Mai? On warmth and rain days alone, Chiang Mai's easiest months were December and January. September ranked 9 of 12.
Is Chiang Mai humid in September? Mean relative humidity was 83%, with about 30 muggy days (dew point of 20°C or more) in the month.
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