Si Racha climate

Name: Si Racha
Address: TH

Si Racha is warmest in April, with average highs of 32 °C, and coldest in December, when nights average 23 °C. September is the wettest month (232 mm) and December the driest (11 mm). Figures are 1991–2020 climate normals.

Across a full year Si Racha averages 1,214 mm of rain and 364 days above 25 °C.

Thailand · population 178,916 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month April 32 °C
Coldest month December 23 °C
Driest month December 11 mm
Wettest month September 232 mm
Least cloud February 39 % cloud
Hottest on record May 36 °C
Coldest on record December 14 °C
Warmest sea May 31 °C

What to expectSi Racha through the year

Si Racha changes little through the year. Average daily highs stay between 30 and 32 °C, so no month stands out as a season in the way it would further from the equator.

Counted across a normal year, 364 days a year reach 25 °C, 216 of them reach 30 °C. The warmest reading in the 1991–2020 record is 36 °C, in May.

Rain is strongly seasonal. September averages 232 mm against 11 mm in December — 21 times as much. Planning around the dry months matters more here than planning around temperature.

The sea off Si Racha is warmest in May at 31 °C and coldest in January at 28 °C. Sea temperature lags the air by a month or two, which is why late summer swims warmer than early summer at the same air temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	30.1 °C	21 mm	44 %
February	30.6 °C	23 mm	39 %
March	31.3 °C	58 mm	45 %
April	31.9 °C	90 mm	58 %
May	31.2 °C	143 mm	81 %
June	30.5 °C	127 mm	88 %
July	30.0 °C	133 mm	88 %
August	29.8 °C	135 mm	90 %
September	29.5 °C	232 mm	89 %
October	29.6 °C	197 mm	77 %
November	30.1 °C	42 mm	56 %
December	29.9 °C	11 mm	50 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C
January	30.1 °C	22.9 °C	26.4 °C	34.1 °C	16.2 °C	31	17
February	30.6 °C	24.1 °C	27.1 °C	34.2 °C	16.2 °C	28	20
March	31.3 °C	25.5 °C	28.1 °C	34.4 °C	17.7 °C	31	26
April	31.9 °C	26.7 °C	29.0 °C	35.1 °C	21.7 °C	30	27
May	31.2 °C	26.8 °C	28.8 °C	35.5 °C	24.5 °C	31	25
June	30.5 °C	26.7 °C	28.4 °C	34.1 °C	24.7 °C	30	20
July	30.0 °C	26.3 °C	28.0 °C	32.6 °C	24.4 °C	31	14
August	29.8 °C	26.2 °C	27.8 °C	33.0 °C	24.6 °C	31	11
September	29.5 °C	25.6 °C	27.4 °C	32.0 °C	23.8 °C	30	9
October	29.6 °C	24.8 °C	26.9 °C	33.2 °C	20.3 °C	31	12
November	30.1 °C	24.0 °C	26.9 °C	33.4 °C	18.1 °C	30	17
December	29.9 °C	22.6 °C	26.2 °C	33.2 °C	14.3 °C	30	17

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind	Sea temp
January	21 mm	5	11 h/day	44 %	70 %	14 km/h	27.5 °C
February	23 mm	5	12 h/day	39 %	74 %	15 km/h	28.0 °C
March	58 mm	10	12 h/day	45 %	77 %	15 km/h	29.0 °C
April	90 mm	14	12 h/day	58 %	77 %	14 km/h	30.1 °C
May	143 mm	21	13 h/day	81 %	80 %	15 km/h	30.6 °C
June	127 mm	21	13 h/day	88 %	79 %	16 km/h	30.2 °C
July	133 mm	22	13 h/day	88 %	80 %	17 km/h	29.7 °C
August	135 mm	23	13 h/day	90 %	80 %	17 km/h	29.4 °C
September	232 mm	25	12 h/day	89 %	83 %	13 km/h	29.4 °C
October	197 mm	22	12 h/day	77 %	83 %	12 km/h	29.4 °C
November	42 mm	7	12 h/day	56 %	73 %	15 km/h	28.9 °C
December	11 mm	3	11 h/day	50 %	66 %	16 km/h	27.9 °C

Where Si Racha ranks

Ranking	Position	Value
Warmest sea temperatures in Asia in May	6th of 50	31 °C
Warmest sea temperatures in the world in May	7th of 50	31 °C
Warmest sea temperatures in Asia in April	16th of 50	30 °C
Warmest sea temperatures in the world in April	16th of 50	30 °C
Best beach destinations in Asia in December	36th of 50	95/100
Warmest sea temperatures in Asia in June	39th of 50	30 °C

Planning a trip? See the best time to visit Si Racha.

QuestionsCommon questions about Si Racha’s climate

When is the best time to visit Si Racha?

That depends on what you want, so the honest answer is a comparison rather than a single month. January, November, December sit closest to 20 °C on average, April is the warmest month and December the driest. The month-by-month table above has the full picture.

How hot does Si Racha get?

In April, the warmest month, daily highs average 32 °C. About 216 days a year pass 30 °C. The highest value in the 1991–2020 record is 36 °C.

How cold does it get in winter?

Nights average 23 °C in December, the coldest month. Freezing nights are not part of a normal year here.

Which month is wettest in Si Racha?

September, averaging 232 mm over 25 days with rain. The driest month is December with 11 mm. The year as a whole averages 1,214 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Si Racha rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Data point: 13.173°, 100.932° (the coordinates the reanalysis values are taken for)
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. 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.