Si Racha weather in May

In May, Si Racha has daytime highs averaging 31 °C, nights around 27 °C, with 21 wet days, and a sea temperature of 31 °C. Figures are 1991–2020 climate normals.

  1. Jan 26°
  2. Feb 27°
  3. Mar 28°
  4. Apr 29°
  5. May 29°
  6. Jun 28°
  7. Jul 28°
  8. Aug 28°
  9. Sep 27°
  10. Oct 27°
  11. Nov 27°
  12. Dec 26°

Daily temperatures through May

24°30°35°18152229
Daily highDaily low Day of month on the horizontal axis. Highs peak at 32.0 °C and lows bottom out at 26.4 °C.

How May 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 May31.8 °C27.0 °C56 %
11–20 May31.0 °C26.6 °C73 %
21–31 May30.8 °C26.7 °C72 %
0%50%100%151015202530
Chance of a wet day (over 1 mm) by date in May. Wettest date over the 30 years: May 18, at 90 %. Single dates are noisy — read the shape, not the spikes.

What to expect

Measure Typical May Share of the month
Days above 25 °C 31 of 31 100 %
Days above 30 °C 25 of 31 79 %
Days below 0 °C 0 of 31 0 %
Days with more than 1 mm rain 21 of 31 67 %

Conditions in May

MeasureAverage
Mean temperature 29 °C
Record high (1991–2020) 36 °C
Record low (1991–2020) 25 °C
Relative humidity 80 %
Wind speed 15 km/h
Cloud cover 81 %

Where Si Racha ranks in May

RankingPositionValue
Warmest sea temperatures in Asia in May6thof 5031 °C
Warmest sea temperatures in the world in May7thof 5031 °C

May compared with the months around it

Month Avg high Rainfall Cloud
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 %

See all twelve months for Si Racha

Nearby destinations in May

Destination Avg high Wet days Sea
Si Racha 31 °C 21 31
Chon Buri 32 °C 21 31
Samut Prakan 33 °C 19 31

QuestionsMay in Si Racha, answered

How warm is Si Racha in May?

Daily highs average 31 °C and nights fall to about 27 °C, a spread of 4.4 °C between afternoon and dawn. That makes May the 2nd warmest month of the year here.

Does it rain much in Si Racha in May?

May averages 143 mm of rain, spread over about 21 of the 31 days — 67 % of the month. Cloud cover averages 81 % of the sky.

Is the sea warm enough to swim in May?

The sea averages 31 °C off Si Racha in May. 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 May?

Si Racha averages 13 hours between sunrise and sunset in May. 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.