Alor Setar weather in September

In September, Alor Setar has daytime highs averaging 29 °C, nights around 24 °C, with 26 wet days, and a sea temperature of 30 °C. Figures are 1991–2020 climate normals.

  1. Jan 27°
  2. Feb 28°
  3. Mar 28°
  4. Apr 27°
  5. May 27°
  6. Jun 27°
  7. Jul 27°
  8. Aug 27°
  9. Sep 26°
  10. Oct 26°
  11. Nov 26°
  12. Dec 26°

Daily temperatures through September

22°27°32°18152229
Daily highDaily low Day of month on the horizontal axis. Highs peak at 29.8 °C and lows bottom out at 24.0 °C.

How September develops

Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.

DaysAvg highAvg lowChance of rain
1–10 September29.5 °C24.1 °C88 %
11–20 September29.4 °C24.2 °C85 %
21–30 September29.4 °C24.1 °C90 %
0%50%100%151015202530
Chance of a wet day (over 1 mm) by date in September. Wettest date over the 30 years: September 3, at 97 %. Single dates are noisy — read the shape, not the spikes.

What to expect

Measure Typical September Share of the month
Days above 25 °C 30 of 30 100 %
Days above 30 °C 9.4 of 30 31 %
Days below 0 °C 0 of 30 0 %
Days with more than 1 mm rain 26 of 30 88 %

Conditions in September

MeasureAverage
Mean temperature 26 °C
Record high (1991–2020) 33 °C
Record low (1991–2020) 22 °C
Relative humidity 88 %
Wind speed 13 km/h
Cloud cover 88 %

Where Alor Setar ranks in September

RankingPositionValue
Warmest sea temperatures in Asia in September26thof 5030 °C
Warmest sea temperatures in the world in September40thof 5030 °C

September compared with the months around it

Month Avg high Rainfall Cloud
July 29.8 °C 196 mm 84 %
August 29.7 °C 235 mm 85 %
September 29.4 °C 259 mm 88 %
October 29.2 °C 305 mm 89 %
November 29.2 °C 218 mm 85 %

See all twelve months for Alor Setar

Nearby destinations in September

Destination Avg high Wet days Sea
Alor Setar 29 °C 26 30
Sungai Petani 29 °C 27 30
Kota Kuala Muda 29 °C 26 30
George Town 29 °C 26 30
Paya Terubong 28 °C 26 30
Bukit Mertajam 29 °C 25 30
Kulim 29 °C 25
Hat Yai 30 °C 24 30

QuestionsSeptember in Alor Setar, answered

How warm is Alor Setar in September?

Daily highs average 29 °C and nights fall to about 24 °C, a spread of 5.3 °C between afternoon and dawn. That makes September the 9th warmest month of the year here.

Does it rain much in Alor Setar in September?

September averages 259 mm of rain, spread over about 26 of the 30 days — 88 % of the month. Cloud cover averages 88 % of the sky.

Is the sea warm enough to swim in September?

The sea averages 30 °C off Alor Setar in September. Most people find water below 20 °C bracing and above 25 °C comfortable for a long swim; this figure is a monthly surface average, so a sheltered bay on a still afternoon can be warmer.

How long are the days in September?

Alor Setar averages 12 hours between sunrise and sunset in September. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.

Data sources and method

Normal period
1991–2020
Dataset version
era5-1991-2020-scores1.1
Last processed

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.