Heat wave in Japan and 2 other countries, 22 June to 5 July 2018

Name: Heat wave in Japan and 2 other countries, 22 June to 5 July 2018
Start: 2018-06-22
End: 2018-07-05
Location: Japan, Russia, Korea, South

Heat wave in Japan and 2 other countries, 22 June to 5 July 2018: 306 records at 117 stations, peak on 2 July 2018. Closed.

Data as of 2026-10-17. Last revised 17 October 2026 (2026-10-17).

Key Facts

Heat wave in Japan and 2 other countries, 22 June to 5 July 2018 set or tied 306 station records at 117 stations.
It ran from 22 June 2018 to 5 July 2018 (14 days) and its peak day was 2 July 2018.
Status: closed.
Shirakawa set a monthly record high minimum temperature of 23.1 C (73.6 F) on 30 June 2018.
The busiest day was 2 July 2018 with 66 records.
The oldest broken record in the ranked list had stood for 65 years.

Footprint

22 June to 5 July 2018

The area covered by Heat wave in Japan and 2 other countries, 22 June to 5 July 2018 is outlined, with 17 of the stations that set records marked, coloured by record type. Made with Natural Earth.

Footprint of Heat wave in Japan and 2 other countries, 22 June to 5 July 2018: stations that set records in the event
Station	Type	Value	Date
Shirakawa	Record high minimum temperature	23.1 C (73.6 F)	2018-06-30
Yamagata	Record high maximum temperature	37.5 C (99.5 F)	2018-06-29
Aikawa	Record high minimum temperature	22.6 C (72.7 F)	2018-06-30
Katsuura	Record high minimum temperature	23.0 C (73.4 F)	2018-06-30
Tokushima	Record high maximum temperature	34.9 C (94.8 F)	2018-06-27
Kawaguchiko	Record high minimum temperature	20.6 C (69.1 F)	2018-06-29
Nagano	Record high maximum temperature	36.4 C (97.5 F)	2018-07-02
Aomori	Record high maximum temperature	30.4 C (86.7 F)	2018-06-23
Sumoto	Record high minimum temperature	24.8 C (76.6 F)	2018-06-27
Kutchan	Record high minimum temperature	18.6 C (65.5 F)	2018-06-29
Hachinohe	Record high minimum temperature	21.1 C (70.0 F)	2018-06-29
Morioka	Record high maximum temperature	33.5 C (92.3 F)	2018-07-01
Izuhara	Record high maximum temperature	31.6 C (88.9 F)	2018-06-24
Onahama	Record high maximum temperature	32.3 C (90.1 F)	2018-06-25
Matsuyama	Record high minimum temperature	27.0 C (80.6 F)	2018-06-28
Wakamatsu	Record high maximum temperature	35.6 C (96.1 F)	2018-06-29
Chiba	Record high minimum temperature	26.2 C (79.2 F)	2018-06-30

Records per Day

Peak day 66

Records set or tied each day from 22 June 2018 to 5 July 2018. The most in one day was 66 on 2 July 2018.

Records per day during Heat wave in Japan and 2 other countries, 22 June to 5 July 2018
Date	Records
2018-06-22	1
2018-06-23	8
2018-06-24	3
2018-06-25	12
2018-06-26	3
2018-06-27	25
2018-06-28	13
2018-06-29	26
2018-06-30	48
2018-07-01	64
2018-07-02	66
2018-07-03	31
2018-07-04	3
2018-07-05	3

Top Records by Margin

Margin over the record replaced

Top records of Heat wave in Japan and 2 other countries, 22 June to 5 July 2018 ranked by margin
Onahama, 06-25	4.1 C (7.4 F)
Yamagata, 06-29	3.5 C (6.3 F)
Shirakawa, 07-02	3.4 C (6.1 F)
Nagano, 07-02	3.3 C (5.9 F)
Morioka, 07-03	3.2 C (5.8 F)
Aomori, 06-23	3.1 C (5.6 F)
Yamagata, 07-02	2.9 C (5.2 F)
Morioka, 07-01	2.8 C (5.0 F)
Matsuyama, 06-28	1.9 C (3.4 F)
Izuhara, 06-24	1.8 C (3.2 F)
Wakamatsu, 06-29	1.3 C (2.3 F)
Chiba, 06-30	1.1 C (2.0 F)
Shirakawa, 06-30	0.9 C (1.6 F)
Tokushima, 06-27	0.3 C (0.5 F)
Kutchan, 06-29	0.3 C (0.5 F)

Margin is how far the new value is beyond the record it replaced. Ties are not shown.

Margin Against Age of the Broken Record

306 records plotted by how far they beat the old record (across) and how many years the old record had stood (up). Long standing records beaten by a wide margin sit in the top right.

Margin against age of the broken record in Heat wave in Japan and 2 other countries, 22 June to 5 July 2018
Margin (C)	Years the old record stood
0.9	63
3.5	31
0.1	63
0.2	62
3.3	63
0.2	56
0.3	55
0.3	55
3.1	60
0.1	54
2.8	64
3.2	63
3.4	63
0.2	54
1.3	40
2.9	63
4.1	39
1.1	40
1.8	60
1.9	60
2.7	63
3.2	48
1.9	63
1.4	56
1.4	63
1.6	63
1.6	55
2.0	63
0.1	40
1.4	63
0.4	39
2.0	55
0.9	60
1.0	57
0.2	39
1.1	53
1.1	60
2.3	55
1.0	57
1.1	57
0.3	65
0.7	60
1.3	57
2.3	52
1.7	55
1.7	55
0.6	59
0.7	57
0.6	57
0.6	60
0.4	63
0.4	60
0.3	60
0.5	56
0.5	56
0.5	57
0.6	56
0.4	63
0.6	56
1.8	44
2.4	36
0.1	57
0.9	56
0.3	57
0.3	60
0.4	57
0.2	60
0.9	52
0.5	56
0.2	57
0.4	57
0.3	57
0.4	55
2.3	40
0.4	56
1.2	51
0.1	57
0.1	57
0.3	57
0.7	56
0.1	57
0.3	55
0.7	52
2.9	31
0.1	56
1.1	44
0.3	53
0.4	52
0.3	52
0.2	55
0.2	55
0.1	55
0.1	20
0.3	53
0.2	55
1.0	40
0.8	47
2.8	24
0.1	55
1.2	33
0.7	47
0.2	52
0.2	20
0.7	40
0.3	48
1.2	33
1.9	31
3.4	17
0.3	40
0.5	40
0.6	9
4.1	7
2.9	17
3.1	20
2.0	20
0.8	39
0.1	39
0.4	45
2.2	17
3.7	8
0.3	39
2.3	20
3.4	4
0.2	40
2.6	20
2.5	12
0.7	39
0.4	40
2.8	20
0.3	39
0.1	40
1.3	27
3.4	7
0.1	39
0.1	39
1.4	27
1.1	27
1.6	17
0.5	0
0.3	0
1.7	20
1.9	16
0.4	31
0.5	28
1.3	20
1.3	20
1.9	7
2.3	8
2.0	17
1.9	17
0.8	20
1.4	17
0.8	20
0.1	39
0.7	20
2.5	8
3.0	7
1.0	17
0.8	17
0.8	23
2.1	7
0.1	27
1.6	13
1.2	17
1.3	21
0.1	27
1.5	16
0.9	17
0.3	24
0.5	27
0.2	27
1.2	17
0.4	24
0.3	24
0.7	20
0.5	20
0.1	27
1.9	8
0.8	17
1.2	7
1.6	8
0.5	20
0.7	20
0.6	17
0.5	17
0.3	20
0.6	20
0.8	17
0.9	17
0.3	20
0.6	17
0.8	17
0.9	17
1.1	12
0.4	20
1.5	8
0.4	17
0.6	19
1.0	16
1.8	0

Compared With Other Events

Station records per event

Station records in Heat wave in Japan and 2 other countries, 22 June to 5 July 2018 compared with similar events
Heat wave in United States and Mexico, 16 January to 14 February 2024	9,869 records
Heat wave in United States, 28 January to 24 February 2026	6,528 records
Heat wave in United States and Mexico, 24 May to 19 June 2020	5,047 records
Heat wave in United States and Mexico, 26 March to 17 April 2021	3,669 records
Heat wave in Germany and 49 other countries, 18 December 2021 to 15 January 2022	3,626 records
Heat wave in Japan and 2 other countries, 22 June to 5 July 2018 (this event)	306 records

Every Record Set

20 of 306

Every record set or tied during Heat wave in Japan and 2 other countries, 22 June to 5 July 2018, in date order
Date	Station	Record	Value	Margin	Years stood	Significance
2018-06-23	Aomori	Record high maximum temperature	30.4 C (86.7 F)	3.1 C (5.6 F)	60	32 of 100 (Routine)
2018-06-24	Izuhara	Record high maximum temperature	31.6 C (88.9 F)	1.8 C (3.2 F)	60	31 of 100 (Routine)
2018-06-25	Onahama	Record high maximum temperature	32.3 C (90.1 F)	4.1 C (7.4 F)	39	31 of 100 (Routine)
2018-06-27	Tokushima	Record high maximum temperature	34.9 C (94.8 F)	0.3 C (0.5 F)	55	33 of 100 (Routine)
2018-06-27	Sumoto	Record high minimum temperature	24.8 C (76.6 F)	0.2 C (0.4 F)	54	32 of 100 (Routine)
2018-06-28	Matsuyama	Record high minimum temperature	27.0 C (80.6 F)	1.9 C (3.4 F)	60	31 of 100 (Routine)
2018-06-29	Yamagata	Record high maximum temperature	37.5 C (99.5 F)	3.5 C (6.3 F)	31	34 of 100 (Routine)
2018-06-29	Kawaguchiko	Record high minimum temperature	20.6 C (69.1 F)	0.2 C (0.4 F)	56	33 of 100 (Routine)
2018-06-29	Kutchan	Record high minimum temperature	18.6 C (65.5 F)	0.3 C (0.5 F)	55	32 of 100 (Routine)
2018-06-29	Hachinohe	Record high minimum temperature	21.1 C (70.0 F)	0.1 C (0.2 F)	54	32 of 100 (Routine)
2018-06-29	Wakamatsu	Record high maximum temperature	35.6 C (96.1 F)	1.3 C (2.3 F)	40	31 of 100 (Routine)
2018-06-30	Shirakawa	Record high minimum temperature	23.1 C (73.6 F)	0.9 C (1.6 F)	63	37 of 100 (Notable)
2018-06-30	Aikawa	Record high minimum temperature	22.6 C (72.7 F)	0.1 C (0.2 F)	63	34 of 100 (Routine)
2018-06-30	Katsuura	Record high minimum temperature	23.0 C (73.4 F)	0.2 C (0.4 F)	62	34 of 100 (Routine)
2018-06-30	Chiba	Record high minimum temperature	26.2 C (79.2 F)	1.1 C (2.0 F)	40	31 of 100 (Routine)
2018-07-01	Morioka	Record high maximum temperature	33.5 C (92.3 F)	2.8 C (5.0 F)	64	32 of 100 (Routine)
2018-07-02	Nagano	Record high maximum temperature	36.4 C (97.5 F)	3.3 C (5.9 F)	63	33 of 100 (Routine)
2018-07-02	Shirakawa	Record high maximum temperature	34.5 C (94.1 F)	3.4 C (6.1 F)	63	32 of 100 (Routine)
2018-07-02	Yamagata	Record high maximum temperature	36.0 C (96.8 F)	2.9 C (5.2 F)	63	31 of 100 (Routine)
2018-07-03	Morioka	Record high maximum temperature	33.9 C (93.0 F)	3.2 C (5.8 F)	63	32 of 100 (Routine)

The daily ledgers keep a limited number of records per day, so this list has 20 of the 306 records the event counts. The counts above use the full total.

Download the Data

Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-17. Events are found by this site from station records and are not official designations. Records are provisional until reprocessed.

Margin (C)	Years the old record stood
0.9	63
3.5	31
0.1	63
0.2	62
3.3	63
0.2	56
0.3	55
0.3	55
3.1	60
0.1	54
2.8	64
3.2	63
3.4	63
0.2	54
1.3	40
2.9	63
4.1	39
1.1	40
1.8	60
1.9	60
2.7	63
3.2	48
1.9	63
1.4	56
1.4	63
1.6	63
1.6	55
2.0	63
0.1	40
1.4	63
0.4	39
2.0	55
0.9	60
1.0	57
0.2	39
1.1	53
1.1	60
2.3	55
1.0	57
1.1	57
0.3	65
0.7	60
1.3	57
2.3	52
1.7	55
1.7	55
0.6	59
0.7	57
0.6	57
0.6	60
0.4	63
0.4	60
0.3	60
0.5	56
0.5	56
0.5	57
0.6	56
0.4	63
0.6	56
1.8	44
2.4	36
0.1	57
0.9	56
0.3	57
0.3	60
0.4	57
0.2	60
0.9	52
0.5	56
0.2	57
0.4	57
0.3	57
0.4	55
2.3	40
0.4	56
1.2	51
0.1	57
0.1	57
0.3	57
0.7	56
0.1	57
0.3	55
0.7	52
2.9	31
0.1	56
1.1	44
0.3	53
0.4	52
0.3	52
0.2	55
0.2	55
0.1	55
0.1	20
0.3	53
0.2	55
1.0	40
0.8	47
2.8	24
0.1	55
1.2	33
0.7	47
0.2	52
0.2	20
0.7	40
0.3	48
1.2	33
1.9	31
3.4	17
0.3	40
0.5	40
0.6	9
4.1	7
2.9	17
3.1	20
2.0	20
0.8	39
0.1	39
0.4	45
2.2	17
3.7	8
0.3	39
2.3	20
3.4	4
0.2	40
2.6	20
2.5	12
0.7	39
0.4	40
2.8	20
0.3	39
0.1	40
1.3	27
3.4	7
0.1	39
0.1	39
1.4	27
1.1	27
1.6	17
0.5	0
0.3	0
1.7	20
1.9	16
0.4	31
0.5	28
1.3	20
1.3	20
1.9	7
2.3	8
2.0	17
1.9	17
0.8	20
1.4	17
0.8	20
0.1	39
0.7	20
2.5	8
3.0	7
1.0	17
0.8	17
0.8	23
2.1	7
0.1	27
1.6	13
1.2	17
1.3	21
0.1	27
1.5	16
0.9	17
0.3	24
0.5	27
0.2	27
1.2	17
0.4	24
0.3	24
0.7	20
0.5	20
0.1	27
1.9	8
0.8	17
1.2	7
1.6	8
0.5	20
0.7	20
0.6	17
0.5	17
0.3	20
0.6	20
0.8	17
0.9	17
0.3	20
0.6	17
0.8	17
0.9	17
1.1	12
0.4	20
1.5	8
0.4	17
0.6	19
1.0	16
1.8	0

Margin (C)	Years the old record stood
0.9	63
3.5	31
0.1	63
0.2	62
3.3	63
0.2	56
0.3	55
0.3	55
3.1	60
0.1	54
2.8	64
3.2	63
3.4	63
0.2	54
1.3	40
2.9	63
4.1	39
1.1	40
1.8	60
1.9	60
2.7	63
3.2	48
1.9	63
1.4	56
1.4	63
1.6	63
1.6	55
2.0	63
0.1	40
1.4	63
0.4	39
2.0	55
0.9	60
1.0	57
0.2	39
1.1	53
1.1	60
2.3	55
1.0	57
1.1	57
0.3	65
0.7	60
1.3	57
2.3	52
1.7	55
1.7	55
0.6	59
0.7	57
0.6	57
0.6	60
0.4	63
0.4	60
0.3	60
0.5	56
0.5	56
0.5	57
0.6	56
0.4	63
0.6	56
1.8	44
2.4	36
0.1	57
0.9	56
0.3	57
0.3	60
0.4	57
0.2	60
0.9	52
0.5	56
0.2	57
0.4	57
0.3	57
0.4	55
2.3	40
0.4	56
1.2	51
0.1	57
0.1	57
0.3	57
0.7	56
0.1	57
0.3	55
0.7	52
2.9	31
0.1	56
1.1	44
0.3	53
0.4	52
0.3	52
0.2	55
0.2	55
0.1	55
0.1	20
0.3	53
0.2	55
1.0	40
0.8	47
2.8	24
0.1	55
1.2	33
0.7	47
0.2	52
0.2	20
0.7	40
0.3	48
1.2	33
1.9	31
3.4	17
0.3	40
0.5	40
0.6	9
4.1	7
2.9	17
3.1	20
2.0	20
0.8	39
0.1	39
0.4	45
2.2	17
3.7	8
0.3	39
2.3	20
3.4	4
0.2	40
2.6	20
2.5	12
0.7	39
0.4	40
2.8	20
0.3	39
0.1	40
1.3	27
3.4	7
0.1	39
0.1	39
1.4	27
1.1	27
1.6	17
0.5	0
0.3	0
1.7	20
1.9	16
0.4	31
0.5	28
1.3	20
1.3	20
1.9	7
2.3	8
2.0	17
1.9	17
0.8	20
1.4	17
0.8	20
0.1	39
0.7	20
2.5	8
3.0	7
1.0	17
0.8	17
0.8	23
2.1	7
0.1	27
1.6	13
1.2	17
1.3	21
0.1	27
1.5	16
0.9	17
0.3	24
0.5	27
0.2	27
1.2	17
0.4	24
0.3	24
0.7	20
0.5	20
0.1	27
1.9	8
0.8	17
1.2	7
1.6	8
0.5	20
0.7	20
0.6	17
0.5	17
0.3	20
0.6	20
0.8	17
0.9	17
0.3	20
0.6	17
0.8	17
0.9	17
1.1	12
0.4	20
1.5	8
0.4	17
0.6	19
1.0	16
1.8	0