Heat wave in United States, 18 to 25 June 2020

Name: Heat wave in United States, 18 to 25 June 2020
Start: 2020-06-18
End: 2020-06-25
Location: United States

Heat wave in United States, 18 to 25 June 2020: 124 records at 71 stations, peak on 23 June 2020. Closed.

Data as of 2026-10-18. Last revised 18 October 2026 (2026-10-18).

Key Facts

Heat wave in United States, 18 to 25 June 2020 set or tied 124 station records at 71 stations.
It ran from 18 June 2020 to 25 June 2020 (8 days) and its peak day was 23 June 2020.
Status: closed.
Jackman set a daily record high maximum temperature of 33.3 C (91.9 F) on 22 June 2020.
The busiest day was 23 June 2020 with 25 records.
The oldest broken record in the ranked list had stood for 125 years.

Footprint

18 to 25 June 2020

The area covered by Heat wave in United States, 18 to 25 June 2020 is outlined, with 16 of the stations that set records marked, coloured by record type. Made with Natural Earth.

Footprint of Heat wave in United States, 18 to 25 June 2020: stations that set records in the event
Station	Type	Value	Date
Jackman	Record high maximum temperature	33.3 C (91.9 F)	2020-06-22
Greenville Muni AP	Record high maximum temperature	32.8 C (91.0 F)	2020-06-20
Canton 4 SE	Record high maximum temperature	33.9 C (93.0 F)	2020-06-23
Auburn	Record high maximum temperature	32.8 C (91.0 F)	2020-06-23
Cornwall	Record high minimum temperature	21.7 C (71.1 F)	2020-06-23
Millinocket Muni AP	Record high maximum temperature	35.6 C (96.1 F)	2020-06-20
Brassua Dam	Record high minimum temperature	18.3 C (64.9 F)	2020-06-23
Norton W	Record high minimum temperature	18.9 C (66.0 F)	2020-06-21
Ft Kent	Record high minimum temperature	18.3 C (64.9 F)	2020-06-20
Portland Jetport	Record high minimum temperature	20.6 C (69.1 F)	2020-06-20
Mt Mansfield	Record high maximum temperature	28.3 C (82.9 F)	2020-06-22
Norfolk 2 SW	Record high maximum temperature	32.2 C (90.0 F)	2020-06-23
Newport	Record high minimum temperature	19.4 C (66.9 F)	2020-06-23
Bridgewater	Record high maximum temperature	35.0 C (95.0 F)	2020-06-19
E Tawas	Record high minimum temperature	21.1 C (70.0 F)	2020-06-21
Sines Deep Creek	Record high minimum temperature	20.0 C (68.0 F)	2020-06-24

Records per Day

Peak day 25

Records set or tied each day from 18 June 2020 to 25 June 2020. The most in one day was 25 on 23 June 2020.

Top Records by Margin

Margin over the record replaced

Top records of Heat wave in United States, 18 to 25 June 2020 ranked by margin
Mt Mansfield, 06-22	4.4 C (7.9 F)
Brassua Dam, 06-23	2.7 C (4.9 F)
Jackman, 06-22	2.2 C (4.0 F)
Greenville Muni AP, 06-20	2.2 C (4.0 F)
Sines Deep Creek, 06-24	2.2 C (4.0 F)
Canton 4 SE, 06-23	1.7 C (3.1 F)
Portland Jetport, 06-20	1.2 C (2.2 F)
Cornwall, 06-23	1.1 C (2.0 F)
Brassua Dam, 06-20	1.1 C (2.0 F)
Canton 4 SE, 06-22	1.1 C (2.0 F)
Ft Kent, 06-20	1.1 C (2.0 F)
Auburn, 06-23	0.6 C (1.1 F)
Cornwall, 06-24	0.6 C (1.1 F)
Millinocket Muni AP, 06-20	0.6 C (1.1 F)
Norton W, 06-21	0.6 C (1.1 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

124 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 United States, 18 to 25 June 2020
Margin (C)	Years the old record stood
2.2	122
2.2	97
1.7	125
0.6	120
0.6	122
1.1	99
0.6	73
2.7	82
1.1	88
0.6	84
1.1	82
0.5	82
0.5	77
1.1	74
4.4	63
0.5	82
1.2	79
0.6	51
2.2	63
0.5	71
0.5	79
2.8	66
1.7	71
1.1	36
1.2	63
0.5	65
0.5	63
0.6	63
0.6	66
0.6	71
1.6	64
2.8	55
0.5	63
1.1	66
1.1	66
0.5	67
0.5	65
1.1	63
1.1	66
1.1	65
1.1	54
0.6	63
0.6	53
2.7	45
0.5	45
0.6	44
0.6	45
3.3	37
1.7	45
3.9	32
3.9	33
0.5	45
1.1	44
1.1	45
0.5	44
2.2	37
1.7	45
0.6	45
1.6	37
1.1	45
1.7	37
0.6	7
0.6	27
0.5	31
0.5	47
1.1	32
0.5	26
0.5	3
2.8	31
2.8	31
1.7	37
1.6	32
1.1	31
0.5	0
0.5	21
1.7	25
0.5	31
2.2	22
1.1	14
2.8	10
1.7	26
1.7	25
0.5	33
1.7	32
0.5	21
2.2	4
1.7	8
1.7	8
1.1	10
0.5	14
1.7	31
0.6	32
1.1	25
0.6	31
0.5	26
2.8	8
1.1	22
1.7	21
1.1	32
0.6	25
2.8	8
0.6	25
0.6	25
2.2	8
0.6	17
2.2	8
0.6	25
1.7	10
1.1	26
1.7	22
1.1	10
1.1	3
0.6	22
0.6	17
1.7	10
1.1	8
0.6	8
1.1	19
1.1	8
1.1	8
0.6	8
0.5	8
0.5	3
0.5	8

Compared With Other Events

Station records per event

Station records in Heat wave in United States, 18 to 25 June 2020 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 United States, 18 to 25 June 2020 (this event)	124 records

Every Record Set

20 of 124

Every record set or tied during Heat wave in United States, 18 to 25 June 2020, in date order
Date	Station	Record	Value	Margin	Years stood	Significance
2020-06-19	Bridgewater	Record high maximum temperature	35.0 C (95.0 F)	0.6 C (1.1 F)	51	32 of 100 (Routine)
2020-06-20	Greenville Muni AP	Record high maximum temperature	32.8 C (91.0 F)	2.2 C (4.0 F)	97	43 of 100 (Notable)
2020-06-20	Millinocket Muni AP	Record high maximum temperature	35.6 C (96.1 F)	0.6 C (1.1 F)	73	40 of 100 (Notable)
2020-06-20	Brassua Dam	Record high maximum temperature	33.3 C (91.9 F)	1.1 C (2.0 F)	88	37 of 100 (Notable)
2020-06-20	Ft Kent	Record high minimum temperature	18.3 C (64.9 F)	1.1 C (2.0 F)	74	34 of 100 (Routine)
2020-06-20	Portland Jetport	Record high minimum temperature	20.6 C (69.1 F)	1.2 C (2.2 F)	79	34 of 100 (Routine)
2020-06-21	Norton W	Record high minimum temperature	18.9 C (66.0 F)	0.6 C (1.1 F)	84	36 of 100 (Notable)
2020-06-21	E Tawas	Record high minimum temperature	21.1 C (70.0 F)	0.5 C (0.9 F)	71	32 of 100 (Routine)
2020-06-22	Jackman	Record high maximum temperature	33.3 C (91.9 F)	2.2 C (4.0 F)	122	44 of 100 (Notable)
2020-06-22	Canton 4 SE	Record high maximum temperature	33.3 C (91.9 F)	1.1 C (2.0 F)	82	36 of 100 (Notable)
2020-06-22	Mt Mansfield	Record high maximum temperature	28.3 C (82.9 F)	4.4 C (7.9 F)	63	34 of 100 (Routine)
2020-06-23	Canton 4 SE	Record high maximum temperature	33.9 C (93.0 F)	1.7 C (3.1 F)	125	43 of 100 (Notable)
2020-06-23	Auburn	Record high maximum temperature	32.8 C (91.0 F)	0.6 C (1.1 F)	120	41 of 100 (Notable)
2020-06-23	Cornwall	Record high minimum temperature	21.7 C (71.1 F)	1.1 C (2.0 F)	99	41 of 100 (Notable)
2020-06-23	Brassua Dam	Record high minimum temperature	18.3 C (64.9 F)	2.7 C (4.9 F)	82	39 of 100 (Notable)
2020-06-23	Norton W	Record high minimum temperature	19.4 C (66.9 F)	0.5 C (0.9 F)	82	35 of 100 (Notable)
2020-06-23	Norfolk 2 SW	Record high maximum temperature	32.2 C (90.0 F)	0.5 C (0.9 F)	77	34 of 100 (Routine)
2020-06-23	Newport	Record high minimum temperature	19.4 C (66.9 F)	0.5 C (0.9 F)	82	34 of 100 (Routine)
2020-06-24	Cornwall	Record high minimum temperature	22.8 C (73.0 F)	0.6 C (1.1 F)	122	41 of 100 (Notable)
2020-06-24	Sines Deep Creek	Record high minimum temperature	20.0 C (68.0 F)	2.2 C (4.0 F)	63	32 of 100 (Routine)

The daily ledgers keep a limited number of records per day, so this list has 20 of the 124 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 2026-10-18. Events are found by this site from station records and are not official designations. Records are provisional until reprocessed.

Date	Records
2020-06-18	4
2020-06-19	13
2020-06-20	22
2020-06-21	16
2020-06-22	22
2020-06-23	25
2020-06-24	21
2020-06-25	1

Margin (C)	Years the old record stood
2.2	122
2.2	97
1.7	125
0.6	120
0.6	122
1.1	99
0.6	73
2.7	82
1.1	88
0.6	84
1.1	82
0.5	82
0.5	77
1.1	74
4.4	63
0.5	82
1.2	79
0.6	51
2.2	63
0.5	71
0.5	79
2.8	66
1.7	71
1.1	36
1.2	63
0.5	65
0.5	63
0.6	63
0.6	66
0.6	71
1.6	64
2.8	55
0.5	63
1.1	66
1.1	66
0.5	67
0.5	65
1.1	63
1.1	66
1.1	65
1.1	54
0.6	63
0.6	53
2.7	45
0.5	45
0.6	44
0.6	45
3.3	37
1.7	45
3.9	32
3.9	33
0.5	45
1.1	44
1.1	45
0.5	44
2.2	37
1.7	45
0.6	45
1.6	37
1.1	45
1.7	37
0.6	7
0.6	27
0.5	31
0.5	47
1.1	32
0.5	26
0.5	3
2.8	31
2.8	31
1.7	37
1.6	32
1.1	31
0.5	0
0.5	21
1.7	25
0.5	31
2.2	22
1.1	14
2.8	10
1.7	26
1.7	25
0.5	33
1.7	32
0.5	21
2.2	4
1.7	8
1.7	8
1.1	10
0.5	14
1.7	31
0.6	32
1.1	25
0.6	31
0.5	26
2.8	8
1.1	22
1.7	21
1.1	32
0.6	25
2.8	8
0.6	25
0.6	25
2.2	8
0.6	17
2.2	8
0.6	25
1.7	10
1.1	26
1.7	22
1.1	10
1.1	3
0.6	22
0.6	17
1.7	10
1.1	8
0.6	8
1.1	19
1.1	8
1.1	8
0.6	8
0.5	8
0.5	3
0.5	8

Margin (C)	Years the old record stood
2.2	122
2.2	97
1.7	125
0.6	120
0.6	122
1.1	99
0.6	73
2.7	82
1.1	88
0.6	84
1.1	82
0.5	82
0.5	77
1.1	74
4.4	63
0.5	82
1.2	79
0.6	51
2.2	63
0.5	71
0.5	79
2.8	66
1.7	71
1.1	36
1.2	63
0.5	65
0.5	63
0.6	63
0.6	66
0.6	71
1.6	64
2.8	55
0.5	63
1.1	66
1.1	66
0.5	67
0.5	65
1.1	63
1.1	66
1.1	65
1.1	54
0.6	63
0.6	53
2.7	45
0.5	45
0.6	44
0.6	45
3.3	37
1.7	45
3.9	32
3.9	33
0.5	45
1.1	44
1.1	45
0.5	44
2.2	37
1.7	45
0.6	45
1.6	37
1.1	45
1.7	37
0.6	7
0.6	27
0.5	31
0.5	47
1.1	32
0.5	26
0.5	3
2.8	31
2.8	31
1.7	37
1.6	32
1.1	31
0.5	0
0.5	21
1.7	25
0.5	31
2.2	22
1.1	14
2.8	10
1.7	26
1.7	25
0.5	33
1.7	32
0.5	21
2.2	4
1.7	8
1.7	8
1.1	10
0.5	14
1.7	31
0.6	32
1.1	25
0.6	31
0.5	26
2.8	8
1.1	22
1.7	21
1.1	32
0.6	25
2.8	8
0.6	25
0.6	25
2.2	8
0.6	17
2.2	8
0.6	25
1.7	10
1.1	26
1.7	22
1.1	10
1.1	3
0.6	22
0.6	17
1.7	10
1.1	8
0.6	8
1.1	19
1.1	8
1.1	8
0.6	8
0.5	8
0.5	3
0.5	8