Tomakomai weather in August

In August, Tomakomai has daytime highs averaging 23 °C, nights around 18 °C, with 15 wet days, and a sea temperature of 20 °C. Figures are 1991–2020 climate normals.

  1. Jan -5°
  2. Feb -4°
  3. Mar -1°
  4. Apr
  5. May 10°
  6. Jun 14°
  7. Jul 18°
  8. Aug 20°
  9. Sep 18°
  10. Oct 12°
  11. Nov
  12. Dec -2°

Daily temperatures through August

15°21°26°18152229
Daily highDaily low Day of month on the horizontal axis. Highs peak at 23.3 °C and lows bottom out at 17.6 °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.

DaysAvg highAvg lowChance of rain
1–10 August23.0 °C18.7 °C44 %
11–20 August22.6 °C18.5 °C48 %
21–31 August22.4 °C18.0 °C49 %
0%50%100%151015202530
Chance of a wet day (over 1 mm) by date in August. Wettest date over the 30 years: August 21, at 70 %. Single dates are noisy — read the shape, not the spikes.

What to expect

Measure Typical August Share of the month
Days above 25 °C 4.5 of 31 15 %
Days above 30 °C 0.03 of 31 0 %
Days below 0 °C 0 of 31 0 %
Days with more than 1 mm rain 15 of 31 47 %

Conditions in August

MeasureAverage
Mean temperature 20 °C
Record high (1991–2020) 30 °C
Record low (1991–2020) 11 °C
Relative humidity 88 %
Wind speed 15 km/h
Cloud cover 74 %

Where Tomakomai ranks in August

RankingPositionValue
The coolest places in Asia in August19thof 5023 °C

August compared with the months around it

Month Avg high Rainfall Cloud
June 16.9 °C 103 mm 72 %
July 20.7 °C 139 mm 77 %
August 22.6 °C 196 mm 74 %
September 20.2 °C 179 mm 66 %
October 14.4 °C 114 mm 55 %

See all twelve months for Tomakomai

Nearby destinations in August

Destination Avg high Wet days Sea
Tomakomai 23 °C 15 20
Sapporo 24 °C 14
Hakodate 24 °C 13 23
Obihiro 24 °C 13
Asahikawa 24 °C 15
Aomori 27 °C 15 23
Kushiro 20 °C 12 17
Hachinohe 26 °C 13 21
Hirosaki 27 °C 16

QuestionsAugust in Tomakomai, answered

How warm is Tomakomai in August?

Daily highs average 23 °C and nights fall to about 18 °C, a spread of 4.3 °C between afternoon and dawn. That makes August the 1st warmest month of the year here.

Does it rain much in Tomakomai in August?

August averages 196 mm of rain, spread over about 15 of the 31 days — 47 % of the month. Cloud cover averages 74 % of the sky.

Is the sea warm enough to swim in August?

The sea averages 20 °C off Tomakomai 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?

Tomakomai averages 14 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.