Kumagaya weather in September

In September, Kumagaya has daytime highs averaging 26 °C, nights around 19 °C, with 16 wet days. Figures are 1991–2020 climate normals.

  1. Jan 3°
  2. Feb 4°
  3. Mar 7°
  4. Apr 13°
  5. May 18°
  6. Jun 21°
  7. Jul 25°
  8. Aug 26°
  9. Sep 22°
  10. Oct 17°
  11. Nov 11°
  12. Dec 5°

Daily temperatures through September

13° 22° 31° 18152229
Daily high Daily low Day of month on the horizontal axis. Highs peak at 28.8 °C and lows bottom out at 15.9 °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.

Days Avg high Avg low Chance of rain
1–10 September 28.1 °C 21.5 °C 54 %
11–20 September 26.3 °C 19.7 °C 53 %
21–30 September 23.7 °C 17.2 °C 50 %
0% 50% 100% 1 5 10 15 20 25 30
Chance of a wet day (over 1 mm) by date in September. Wettest date over the 30 years: September 8, at 70 %. Single dates are noisy — read the shape, not the spikes.

What to expect

Measure Typical September Share of the month
Days above 25 °C 18 of 30 60 %
Days above 30 °C 3.4 of 30 11 %
Days below 0 °C 0 of 30 0 %
Days with more than 1 mm rain 16 of 30 52 %

Conditions in September

MeasureAverage
Mean temperature 22 °C
Record high (1991–2020) 35 °C
Record low (1991–2020) 9.7 °C
Relative humidity 81 %
Wind speed 12 km/h
Cloud cover 70 %

September compared with the months around it

Month Avg high Rainfall Cloud
July 28.6 °C 211 mm 78 %
August 29.9 °C 170 mm 70 %
September 26.0 °C 225 mm 70 %
October 20.4 °C 211 mm 61 %
November 15.2 °C 79 mm 47 %

See all twelve months for Kumagaya

QuestionsSeptember in Kumagaya, answered

How warm is Kumagaya in September?

Daily highs average 26 °C and nights fall to about 19 °C, a spread of 6.6 °C between afternoon and dawn. That makes September the 3rd warmest month of the year here.

Does it rain much in Kumagaya in September?

September averages 225 mm of rain, spread over about 16 of the 30 days — 52 % of the month. Cloud cover averages 70 % of the sky.

How long are the days in September?

Kumagaya 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.