Temperature observation results

Last Updated October 27, 2023

The Institute of Environmental Science conducts temperature observations at multiple elementary schools in the city every year in order to understand the heat situation in the city, which has become hot due to global warming and the heat island phenomenon.
This page contains the temperature observation results for 2023 and past observations.
For more information on measures taken by the Institute of Environmental Science's efforts to combat urban heat, please also see the City Heat Countermeasures page.

Temperature Observation Results in 2023

Observation results from July to August (summer)

The average temperature from July to August at all observation points reached the highest level of the past 10 years - The number of days in midsummer, hot days, and tropical nights have updated records at the most observation points ~

From July to August, all points observed for each point compared with the observations over the past 10 years (1925 to 4) for each point. ※The average temperature was the highest, and the heat was severe throughout the city.
In addition, records have been updated at locations where the highest number of summer days, hot days, and tropical nights have been updated.
(* We observed at 36 locations in the city from July to August, but this is the result of 34 locations in the city due to missing two locations.)

Click here for details on the observation results from July to August (summer).

Press release document "Average temperature from July to August at all observation points has reached the highest value over the past 10 years-Renew records at the most observation points for midsummer, hot days, and tropical nights are updated at the most observation points-" (PDF: 2,012KB) )

Temperature Observation Results in September

The average temperature in Yokohama City in September was the highest since the start of observation-~ The number of days in midsummer and tropical nights have reached the highest record.

Since the temperature observation in September, the monthly average temperature has been the highest since 2014, and the heat was severe in September, following the heat was severe in September, following the July-August, when the entire city was intense.
Especially in mid-September, the hot time zone became longer.

Click here for more information about the results of the observations in September.

Press release document "The average temperature in Yokohama City in September was the highest since the start of observation-The number of days in midsummer and tropical nights have updated the highest record-" (PDF: 1,593KB)

List of 2023 and Past Temperature Observation Results

Temperature observation results from July to August (summer) in 2023 and the past 10 years (2013-4)

Temperature observation results from July to August (summer) in 2023 and the past 10 years (2013-4)
Year	Number of observation points	Temperature (°C)						Number of days by index (Sun) (*1)
		Average temperature by month		Average temperature(*2)			Maximum temperature	Midsummer days		Days of hot days		Tropical night days
		July	August	Average	Best	Minimum	Maximum temperature	Maximum number	Minimum	Maximum number	Minimum	Maximum number	Minimum
2013	43	26.6	28.5	27.6	28.3	26.7	39.9	50	37	18	2	39	16
2014	43	26.1	26.9	26.5	27.1	25.7	37.0	41	26	13	0	31	7
2015	43	26.2	27.0	26.6	27.2	25.8	38.0	40	31	13	0	40	11
2016	44	25.5	27.4	26.5	27.4	25.6	40.2	43	24	9	1	32	4
2017	44	27.2	26.7	27.0	27.8	26.1	38.0	49	29	8	0	37	10
2018	44	28.2	28.3	28.2	29.1	27.3	39.4	53	40	19	1	51	25
2019	44	24.4	28.6	26.5	27.1	25.6	37.9	40	26	14	0	37	19
2020	43	24.5	29.4	26.9	27.8	26.0	38.3	38	29	20	0	36	8
2021	41	26.1	27.6	26.9	27.7	25.9	37.8	46	30	10	0	40	9
2022	36	27.3	27.7	27.5	28.3	26.6	37.8	48	33	9	0	44	22
2023	36	28.5	29.2	28.8	29.6	28.0	39.4	60	51	26	2	54	20

（※１） Minimize the number of days at the highest point in each year and the lowest number of days at the lowest point.
（※２） The average temperature at the highest point in each year and the lowest average temperature at the lowest point.

Temperature observation results for 2023 and the last nine years (2014-4)

Temperature observation results for 2023 and the last nine years (2014-4)
Year	Number of observation points	Number of points to be analyzed	Temperature (°C)				Number of days by index (Sun) (*3)
			Average temperature(*4)			Maximum temperature	Midsummer days		Tropical night days
			Average	Best	Minimum	Maximum temperature	Maximum number	Minimum	Maximum number	Minimum
2014	43	41	22.8	23.6	21.9	32.6	9	0	2	0
2015	43	43	22.9	23.7	21.9	32.1	9	0	1	0
2016	44	44	24.6	25.5	23.9	35.1	14	5	11	0
2017	44	42	23.0	23.9	22.1	34.0	8	1	0	0
2018	44	41	23.1	23.8	22.4	34.0	10	2	5	1
2019	44	44	25.4	26.1	24.4	36.3	16	8	7	0
2020	43	43	24.6	25.3	23.8	36.3	14	9	12	2
2021	41	41	22.7	23.3	21.9	33.7	6	1	1	0
2022	36	36	24.8	25.4	23.9	35.1	18	1	6	1
2023	34	34	26.9	27.5	26.1	36.1	24	17	20	2

（※３） Minimize the number of days at the highest point in each year and the lowest number of days at the lowest point.
（※４） The average temperature at the highest point in each year and the lowest average temperature at the lowest point.