Heat wave in Japan and 5 other countries, 21 March to 5 April 2021

Name: Heat wave in Japan and 5 other countries, 21 March to 5 April 2021
Start: 2021-03-21
End: 2021-04-05
Location: Japan, Russia, China, Korea, North, Mongolia, Korea, South

Heat wave in Japan and 5 other countries, 21 March to 5 April 2021: 480 records at 226 stations, peak on 2 April 2021. Closed.

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

Key Facts

Heat wave in Japan and 5 other countries, 21 March to 5 April 2021 set or tied 480 station records at 226 stations.
It ran from 21 March 2021 to 5 April 2021 (16 days) and its peak day was 2 April 2021.
Status: closed.
Ternej set a daily record high minimum temperature of 4.1 C (39.4 F) on 30 March 2021.
The busiest day was 2 April 2021 with 70 records.
The oldest broken record in the ranked list had stood for 83 years.

Footprint

21 March to 5 April 2021

The area covered by Heat wave in Japan and 5 other countries, 21 March to 5 April 2021 is outlined, with 19 of the stations that set records marked, coloured by record type. Made with Natural Earth.

Footprint of Heat wave in Japan and 5 other countries, 21 March to 5 April 2021: stations that set records in the event
Station	Type	Value	Date
Ternej	Record high minimum temperature	4.1 C (39.4 F)	2021-03-30
Fukuyama	Record high maximum temperature	24.1 C (75.4 F)	2021-03-26
Takayama	Record high minimum temperature	9.5 C (49.1 F)	2021-03-28
Ishinomaki	Record high minimum temperature	11.2 C (52.2 F)	2021-03-29
Muroran	Record high minimum temperature	5.1 C (41.2 F)	2021-03-24
Babuskin	Record high maximum temperature	10.2 C (50.4 F)	2021-03-22
Ust-Njukzha	Record high minimum temperature	-2.7 C (27.1 F)	2021-03-27
Mito	Record high minimum temperature	13.7 C (56.7 F)	2021-03-29
Onahama	Record high minimum temperature	13.2 C (55.8 F)	2021-03-30
Timiryazevskij	Record high minimum temperature	5.0 C (41.0 F)	2021-04-02
Tsu	Record high minimum temperature	13.7 C (56.7 F)	2021-03-28
Bikin	Record high minimum temperature	5.7 C (42.3 F)	2021-04-02
Hamar-Daban	Record high maximum temperature	9.2 C (48.6 F)	2021-03-21
Saga	Record high maximum temperature	24.6 C (76.3 F)	2021-03-26
Aleksandrovsk-Sahalinskij	Record high minimum temperature	0.5 C (32.9 F)	2021-03-29
Pogranichnoe	Record high minimum temperature	-1.0 C (30.2 F)	2021-03-29
Ushibuka	Record high minimum temperature	18.3 C (64.9 F)	2021-04-02
Tomakomai	Record high minimum temperature	3.4 C (38.1 F)	2021-03-25
Utsunomiya	Record high minimum temperature	12.5 C (54.5 F)	2021-03-29

Records per Day

Peak day 70

Records set or tied each day from 21 March 2021 to 5 April 2021. The most in one day was 70 on 2 April 2021.

Records per day during Heat wave in Japan and 5 other countries, 21 March to 5 April 2021
Date	Records
2021-03-21	4
2021-03-22	14
2021-03-23	17
2021-03-24	38
2021-03-25	29
2021-03-26	25
2021-03-27	26
2021-03-28	62
2021-03-29	56
2021-03-30	29
2021-03-31	12
2021-04-01	33
2021-04-02	70
2021-04-03	51
2021-04-04	11
2021-04-05	3

Top Records by Margin

Margin over the record replaced

Top records of Heat wave in Japan and 5 other countries, 21 March to 5 April 2021 ranked by margin
Ternej, 03-30	3.7 C (6.7 F)
Bikin, 04-02	3.5 C (6.3 F)
Ust-Njukzha, 03-27	3.0 C (5.4 F)
Ushibuka, 04-02	2.7 C (4.9 F)
Utsunomiya, 03-29	2.7 C (4.9 F)
Muroran, 03-24	2.1 C (3.8 F)
Saga, 03-26	1.9 C (3.4 F)
Timiryazevskij, 04-02	1.8 C (3.2 F)
Tomakomai, 03-25	1.6 C (2.9 F)
Mito, 03-29	1.2 C (2.2 F)
Pogranichnoe, 03-29	1.2 C (2.2 F)
Ishinomaki, 03-29	1.0 C (1.8 F)
Tsu, 03-28	0.7 C (1.3 F)
Onahama, 03-30	0.6 C (1.1 F)
Takayama, 03-28	0.5 C (0.9 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

480 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 5 other countries, 21 March to 5 April 2021
Margin (C)	Years the old record stood
3.7	75
0.1	66
1.0	53
0.5	61
2.1	68
0.6	55
1.2	49
3.0	75
0.1	83
1.8	68
0.7	47
3.5	62
0.3	52
1.9	67
2.7	56
0.2	83
0.5	75
1.2	76
1.6	68
2.7	58
2.9	56
1.7	67
2.7	56
2.0	67
1.3	67
1.8	67
2.1	60
1.1	45
0.6	76
1.5	68
1.3	68
1.3	67
1.1	67
2.5	56
1.3	67
1.2	67
1.0	67
2.6	62
2.3	50
1.1	64
0.8	67
1.3	67
2.1	56
1.7	56
0.7	62
3.6	52
1.5	67
0.5	68
0.6	67
2.5	48
0.6	67
0.6	67
0.5	67
2.4	48
1.9	54
1.6	56
1.7	56
0.2	70
4.2	34
0.2	68
0.8	62
1.0	59
2.0	54
1.9	48
1.1	56
1.3	56
1.2	56
2.3	54
0.3	67
0.3	67
0.7	62
1.8	56
1.1	58
0.3	67
1.5	55
1.5	48
0.7	59
1.6	54
0.5	60
0.9	58
0.9	24
0.4	63
1.2	56
0.1	62
0.7	62
0.4	62
0.1	62
0.7	58
1.5	50
0.4	59
0.8	54
0.7	54
0.6	56
0.6	56
0.8	56
0.6	56
0.6	62
0.4	58
1.6	52
3.4	28
0.3	58
0.3	59
1.2	54
3.1	34
0.5	54
0.6	54
0.6	54
0.4	58
1.1	50
0.4	54
0.5	54
1.7	48
0.2	56
0.6	54
6.5	31
2.3	46
0.5	54
1.8	34
2.3	40
0.8	55
2.8	36
0.3	54
0.8	48
0.2	54
1.9	48
1.1	54
1.5	50
1.3	50
1.2	51
2.7	42
4.3	18
0.2	52
2.9	24
0.2	52
0.9	44
0.3	56
2.8	28
1.0	52
0.4	48
0.6	48
1.2	46
2.2	40
1.0	39
0.3	48
1.3	6
2.3	23
1.3	36
0.2	48
2.0	36
0.4	38
1.0	40
1.1	39
0.7	43
0.5	38
2.9	27
0.9	5
1.4	0
1.7	27
1.8	28
2.6	24
1.5	28
2.5	28
1.7	28
1.3	42
1.4	32
4.0	18
0.2	43
0.7	38
4.0	28
3.3	19
3.0	18
0.8	34
0.6	36
2.7	23
1.9	32
0.7	36
0.4	43
2.2	28
3.3	31
0.3	39
0.9	4
1.1	32
0.9	40
0.4	31
1.8	0
0.2	46
0.3	40
0.1	39
1.7	27
0.9	1
1.1	28
0.9	31
0.4	42
0.7	36
0.8	36
0.9	2
2.3	28
0.4	32
1.2	24
1.1	31

Compared With Other Events

Station records per event

Station records in Heat wave in Japan and 5 other countries, 21 March to 5 April 2021 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 5 other countries, 21 March to 5 April 2021 (this event)	480 records

Every Record Set

20 of 480

Every record set or tied during Heat wave in Japan and 5 other countries, 21 March to 5 April 2021, in date order
Date	Station	Record	Value	Margin	Years stood	Significance
2021-03-21	Hamar-Daban	Record high maximum temperature	9.2 C (48.6 F)	0.2 C (0.4 F)	83	32 of 100 (Routine)
2021-03-22	Babuskin	Record high maximum temperature	10.2 C (50.4 F)	0.1 C (0.2 F)	83	34 of 100 (Routine)
2021-03-24	Muroran	Record high minimum temperature	5.1 C (41.2 F)	2.1 C (3.8 F)	68	35 of 100 (Notable)
2021-03-25	Tomakomai	Record high minimum temperature	3.4 C (38.1 F)	1.6 C (2.9 F)	68	31 of 100 (Routine)
2021-03-26	Fukuyama	Record high maximum temperature	24.1 C (75.4 F)	0.1 C (0.2 F)	66	37 of 100 (Notable)
2021-03-26	Saga	Record high maximum temperature	24.6 C (76.3 F)	1.9 C (3.4 F)	67	32 of 100 (Routine)
2021-03-27	Ust-Njukzha	Record high minimum temperature	-2.7 C (27.1 F)	3.0 C (5.4 F)	75	34 of 100 (Routine)
2021-03-28	Takayama	Record high minimum temperature	9.5 C (49.1 F)	0.5 C (0.9 F)	61	36 of 100 (Notable)
2021-03-28	Tsu	Record high minimum temperature	13.7 C (56.7 F)	0.7 C (1.3 F)	47	33 of 100 (Routine)
2021-03-29	Ishinomaki	Record high minimum temperature	11.2 C (52.2 F)	1.0 C (1.8 F)	53	36 of 100 (Notable)
2021-03-29	Mito	Record high minimum temperature	13.7 C (56.7 F)	1.2 C (2.2 F)	49	34 of 100 (Routine)
2021-03-29	Ishinomaki	Record high maximum temperature	20.7 C (69.3 F)	0.3 C (0.5 F)	52	32 of 100 (Routine)
2021-03-29	Aleksandrovsk-Sahalinskij	Record high minimum temperature	0.5 C (32.9 F)	0.5 C (0.9 F)	75	32 of 100 (Routine)
2021-03-29	Pogranichnoe	Record high minimum temperature	-1.0 C (30.2 F)	1.2 C (2.2 F)	76	32 of 100 (Routine)
2021-03-29	Utsunomiya	Record high minimum temperature	12.5 C (54.5 F)	2.7 C (4.9 F)	58	31 of 100 (Routine)
2021-03-30	Ternej	Record high minimum temperature	4.1 C (39.4 F)	3.7 C (6.7 F)	75	39 of 100 (Notable)
2021-03-30	Onahama	Record high minimum temperature	13.2 C (55.8 F)	0.6 C (1.1 F)	55	34 of 100 (Routine)
2021-04-02	Timiryazevskij	Record high minimum temperature	5.0 C (41.0 F)	1.8 C (3.2 F)	68	34 of 100 (Routine)
2021-04-02	Bikin	Record high minimum temperature	5.7 C (42.3 F)	3.5 C (6.3 F)	62	33 of 100 (Routine)
2021-04-02	Ushibuka	Record high minimum temperature	18.3 C (64.9 F)	2.7 C (4.9 F)	56	32 of 100 (Routine)

The daily ledgers keep a limited number of records per day, so this list has 20 of the 480 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
3.7	75
0.1	66
1.0	53
0.5	61
2.1	68
0.6	55
1.2	49
3.0	75
0.1	83
1.8	68
0.7	47
3.5	62
0.3	52
1.9	67
2.7	56
0.2	83
0.5	75
1.2	76
1.6	68
2.7	58
2.9	56
1.7	67
2.7	56
2.0	67
1.3	67
1.8	67
2.1	60
1.1	45
0.6	76
1.5	68
1.3	68
1.3	67
1.1	67
2.5	56
1.3	67
1.2	67
1.0	67
2.6	62
2.3	50
1.1	64
0.8	67
1.3	67
2.1	56
1.7	56
0.7	62
3.6	52
1.5	67
0.5	68
0.6	67
2.5	48
0.6	67
0.6	67
0.5	67
2.4	48
1.9	54
1.6	56
1.7	56
0.2	70
4.2	34
0.2	68
0.8	62
1.0	59
2.0	54
1.9	48
1.1	56
1.3	56
1.2	56
2.3	54
0.3	67
0.3	67
0.7	62
1.8	56
1.1	58
0.3	67
1.5	55
1.5	48
0.7	59
1.6	54
0.5	60
0.9	58
0.9	24
0.4	63
1.2	56
0.1	62
0.7	62
0.4	62
0.1	62
0.7	58
1.5	50
0.4	59
0.8	54
0.7	54
0.6	56
0.6	56
0.8	56
0.6	56
0.6	62
0.4	58
1.6	52
3.4	28
0.3	58
0.3	59
1.2	54
3.1	34
0.5	54
0.6	54
0.6	54
0.4	58
1.1	50
0.4	54
0.5	54
1.7	48
0.2	56
0.6	54
6.5	31
2.3	46
0.5	54
1.8	34
2.3	40
0.8	55
2.8	36
0.3	54
0.8	48
0.2	54
1.9	48
1.1	54
1.5	50
1.3	50
1.2	51
2.7	42
4.3	18
0.2	52
2.9	24
0.2	52
0.9	44
0.3	56
2.8	28
1.0	52
0.4	48
0.6	48
1.2	46
2.2	40
1.0	39
0.3	48
1.3	6
2.3	23
1.3	36
0.2	48
2.0	36
0.4	38
1.0	40
1.1	39
0.7	43
0.5	38
2.9	27
0.9	5
1.4	0
1.7	27
1.8	28
2.6	24
1.5	28
2.5	28
1.7	28
1.3	42
1.4	32
4.0	18
0.2	43
0.7	38
4.0	28
3.3	19
3.0	18
0.8	34
0.6	36
2.7	23
1.9	32
0.7	36
0.4	43
2.2	28
3.3	31
0.3	39
0.9	4
1.1	32
0.9	40
0.4	31
1.8	0
0.2	46
0.3	40
0.1	39
1.7	27
0.9	1
1.1	28
0.9	31
0.4	42
0.7	36
0.8	36
0.9	2
2.3	28
0.4	32
1.2	24
1.1	31

Margin (C)	Years the old record stood
3.7	75
0.1	66
1.0	53
0.5	61
2.1	68
0.6	55
1.2	49
3.0	75
0.1	83
1.8	68
0.7	47
3.5	62
0.3	52
1.9	67
2.7	56
0.2	83
0.5	75
1.2	76
1.6	68
2.7	58
2.9	56
1.7	67
2.7	56
2.0	67
1.3	67
1.8	67
2.1	60
1.1	45
0.6	76
1.5	68
1.3	68
1.3	67
1.1	67
2.5	56
1.3	67
1.2	67
1.0	67
2.6	62
2.3	50
1.1	64
0.8	67
1.3	67
2.1	56
1.7	56
0.7	62
3.6	52
1.5	67
0.5	68
0.6	67
2.5	48
0.6	67
0.6	67
0.5	67
2.4	48
1.9	54
1.6	56
1.7	56
0.2	70
4.2	34
0.2	68
0.8	62
1.0	59
2.0	54
1.9	48
1.1	56
1.3	56
1.2	56
2.3	54
0.3	67
0.3	67
0.7	62
1.8	56
1.1	58
0.3	67
1.5	55
1.5	48
0.7	59
1.6	54
0.5	60
0.9	58
0.9	24
0.4	63
1.2	56
0.1	62
0.7	62
0.4	62
0.1	62
0.7	58
1.5	50
0.4	59
0.8	54
0.7	54
0.6	56
0.6	56
0.8	56
0.6	56
0.6	62
0.4	58
1.6	52
3.4	28
0.3	58
0.3	59
1.2	54
3.1	34
0.5	54
0.6	54
0.6	54
0.4	58
1.1	50
0.4	54
0.5	54
1.7	48
0.2	56
0.6	54
6.5	31
2.3	46
0.5	54
1.8	34
2.3	40
0.8	55
2.8	36
0.3	54
0.8	48
0.2	54
1.9	48
1.1	54
1.5	50
1.3	50
1.2	51
2.7	42
4.3	18
0.2	52
2.9	24
0.2	52
0.9	44
0.3	56
2.8	28
1.0	52
0.4	48
0.6	48
1.2	46
2.2	40
1.0	39
0.3	48
1.3	6
2.3	23
1.3	36
0.2	48
2.0	36
0.4	38
1.0	40
1.1	39
0.7	43
0.5	38
2.9	27
0.9	5
1.4	0
1.7	27
1.8	28
2.6	24
1.5	28
2.5	28
1.7	28
1.3	42
1.4	32
4.0	18
0.2	43
0.7	38
4.0	28
3.3	19
3.0	18
0.8	34
0.6	36
2.7	23
1.9	32
0.7	36
0.4	43
2.2	28
3.3	31
0.3	39
0.9	4
1.1	32
0.9	40
0.4	31
1.8	0
0.2	46
0.3	40
0.1	39
1.7	27
0.9	1
1.1	28
0.9	31
0.4	42
0.7	36
0.8	36
0.9	2
2.3	28
0.4	32
1.2	24
1.1	31