Plymouth weather in August

In August, Plymouth has daytime highs averaging 29 °C, nights around 26 °C, with 17 wet days, and a sea temperature of 29 °C. Figures are 1991–2020 climate normals.

  1. Jan 25°
  2. Feb 25°
  3. Mar 25°
  4. Apr 26°
  5. May 26°
  6. Jun 27°
  7. Jul 27°
  8. Aug 27°
  9. Sep 27°
  10. Oct 27°
  11. Nov 26°
  12. Dec 26°

Daily temperatures through August

23° 28° 32° 18152229
Daily high Daily low Day of month on the horizontal axis. Highs peak at 29.1 °C and lows bottom out at 25.7 °C.

How August 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.

Days Avg high Avg low Chance of rain
1–10 August 28.8 °C 25.9 °C 56 %
11–20 August 28.9 °C 26.0 °C 53 %
21–31 August 28.8 °C 26.0 °C 57 %
0% 50% 100% 1 5 10 15 20 25 30
Chance of a wet day (over 1 mm) by date in August. Wettest date over the 30 years: August 16, at 73 %. Single dates are noisy — read the shape, not the spikes.

What to expect

Measure Typical August Share of the month
Days above 25 °C 31 of 31 100 %
Days above 30 °C 1.3 of 31 4 %
Days below 0 °C 0 of 31 0 %
Days with more than 1 mm rain 17 of 31 55 %

Conditions in August

MeasureAverage
Mean temperature 27 °C
Record high (1991–2020) 31 °C
Record low (1991–2020) 24 °C
Relative humidity 78 %
Wind speed 31 km/h
Cloud cover 49 %

August compared with the months around it

Month Avg high Rainfall Cloud
June 28.6 °C 46 mm 54 %
July 28.6 °C 71 mm 47 %
August 28.8 °C 89 mm 49 %
September 28.7 °C 112 mm 59 %
October 28.3 °C 119 mm 55 %

See all twelve months for Plymouth

QuestionsAugust in Plymouth, answered

How warm is Plymouth in August?

Daily highs average 29 °C and nights fall to about 26 °C, a spread of 2.9 °C between afternoon and dawn. That makes August the 1st warmest month of the year here.

Does it rain much in Plymouth in August?

August averages 89 mm of rain, spread over about 17 of the 31 days — 55 % of the month. Cloud cover averages 49 % of the sky.

Is the sea warm enough to swim in August?

The sea averages 29 °C off Plymouth in August. 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 August?

Plymouth averages 13 hours between sunrise and sunset in August. 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.